Serendipity, such as this case of prehistoric fossils being perfectly
preserved in a frozen climate, met with modern technology, allows for previous
records in scientific achievements to be surpassed. A 700,000 year-old ancestor to the modern
horse has recently had its DNA fully recovered allowing for the oldest genome
known to be fully sequenced. What do you
make of the use of DNA of other specimens assumed to be related to the ancestor
as references for completing the sequencing?
What other limitations should be considered should prehistoric hominid
DNA be recovered for sequencing? At what
point, if any, could older traditional methods for mapping related organisms
and their evolution become obsolete? Can
genomic sequencing become the sole method for determining how organisms evolve
and are related?
The use of DNA of other specimens assumed to be related to the ancestor as references for completing the sequencing is an interesting concept to me. I feel like that is such a guesswork way to go about things and while I realize there may not be better ways, this seems like a very questionable method. I feel like this method has many limitations including the way that the DNA fragments can break apart. Also, if the DNA is not located in a cold area in ice blocks, it would be even more destroyed and poorly formed. Also, this involves assuming the DNA that is found is from an animal already known in existence. I understand how important this technique would be though, since genomic sequencing is not a practical method when it comes to prehistoric bones.I do think that older traditional methods for mapping related organisms may become obsolete as science advances. With scientists making sure huge strides in genome sequencing, its hard to believe that we will be at a stand still with the process we currently have.
ReplyDeleteI find this article incredibly amazing. Just the fact that science has come this far to be able to sequence a species 700,000 years old is astounding, Obviously, since this method has many limitations it is not ideal. For the information to be as accurate as possible the artifact has to be naturally preserved in a perfect temperature and there has to be a relative of the species to serve as a DNA template. Although these conditions are limiting, they are still quite an improvement from previous methods.In my opinion I do not think genomic sequencing can play the part of the sole method for determining evolution, but, I do think it serves valuable information that sets a theory on the right path. Coupling this with another method could lead to a two-fold flawless process. With this being said, science is constantly improving and evolving so while this may be the most current and cutting edge technology who's to say there wont be something greater in years to come that will replace this.
ReplyDeleteIn terms of limitations, it seems silly but if we were to discover a homoerectus species would we not have to consider this persons autonomy? As funny as it sounds, technically no one received their consent to dip into and share their DNA sequence. I doubt this would ever be considered a limitation, but its something to think about. At what time frame or what cause does it make it ok to take a dead persons DNA without prior permission?
I had the same thought in terms of autonomy and a person's rights to their own genetic information. Autonomy rights and justice in genomic medicine is already a contentious topic and there are many gray areas already. I feel like if scientists ever get to the point of bringing dead species back to life, their autonomy would not be taken into consideration, for many would feel that it's nonexistent. Then of course there would be the debate over, what does one consider to be "life" and "living"? Additionally, can we really apply ethical considerations to the "undead"?
DeleteI hadn't considered this idea of autonomy as a limitation, but now that you bring it up I completely agree that it should be considered. I also agree with Isatu that their autonomy would likely not be taken into consideration because people would feel it was nonexistent. Can we really say this though? It seems to me that if we are ethically not allowed to take DNA from a person who died ten years ago without their consent, why are we allowed to take DNA from a person thousands of years ago without their consent? As Gianna said, where is the cut off for when it is no longer unethical to take someone's DNA without their consent?
DeleteA few decades ago, we would not have even dreamed of sequencing our own genomes. Today, 8 years after the completion of the Human Genome Project, we are able to sequence the genomes of ancient mammals that roamed our planet thousands of years before we even got here. That is absolutely amazing! As I was reading this article, the author stated that a modern day horse was used as a reference to sequence the genome of this ancient ancestor of the horse. I couldn’t help but think about what evolutionary changes may have occurred and if environmental changes in the ancestor of the horse could be seen in the modern-day horse that we know. For the technology that we have today, making use of other DNA specimens as a reference to map the genome of an ancient animals is a good foundation. As the article states, the DNA of this 700,000 year-old horse was preserved due to the frigid climate that it was in for so many years. However, as technology and science continues to advance, methods of sequencing the genomes of ancient plants and animals is also going to evolve. I think genomic sequencing definitely has a huge role in determining how organisms evolve and are related, because even the environment can be taken to account (though epigenetic) but I am not sure that genomic sequencing remain the sole method of determining evolutionary changes forever. I also think Gianna brings up an interesting question when she asks at what point is it permissible to take a deceased person or organism’s DNA without prior permission? As ethical issues are becoming more and more prevalent, the notion of informed consent is key to determining whether research is morally right, and genomic sequencing advances, do we have to start asking people if we can use their DNA? Should we ask them like we ask for organ donations (on drivers licenses)?
ReplyDeleteI believe that the use of current DNA as a reference is a create way to sequence ancient genomes. Instead of trying to make something out of nothing, scientists are able to use current DNA to paint a picture of the past. This gives insight to the development of animals and the impact of domestication, as seen by the horse. It would be cool to see if by sequencing we can figure out the missing link from monkey to humans. This could be a big discovery to see how our brains developed and lead to more discoveries about the human mind and body. I do not think that traditional methods will become obsolete, but will we used as reference. These methods are cheaper and until we are able to completely understand the genomic code will be very useful. One day they will be obsolete but that will not be for many years. Genomic sequencing is key to determining evolution, but in order accurately to see how organisms evolve one needs to look at the epigenetic factors that are not apparent by just looking at the genetic code.
ReplyDeleteUsing the DNA of related specimens to sequence ancient DNA is truly fascinating and remarkable. The ability to sequence the genome of a 700,000 horse only opens the door for more scientific inquiries into other older specimens. I would argue that our ability to sequence entire genomes using reference DNA is the most accurate way of studying evolution. Phylogenic trees are a nice visual representation, but comparing organisms genetically with their most recent ancestor is infinitely more telling of the changes that did occur, besides what is phenotypically observed. I believe that genomic sequencing will surpass all other methods of evolutionary study because it is the most precise method to determine even the smallest changes among ancestral species.
ReplyDeleteIt would certainly be interesting to sequence prehistoric hominid DNA, but I would argue against attempting to incorporate that DNA into the current human genome in order to resurrect the species. Scientifically generating an ancestral species to today’s humans seems entirely unethical.
I believe that this method can be a hit or miss. As Church says, genomic sequencing using living animals related to a prehistoric ancestor may not work all the time. This is because although the genetic information may be very similar, genetic changes may be drastic and mutations such as deletions and deletions of a whole chromosome could occur.
ReplyDeleteI do not believe that genomic sequencing can be the only determinant of evolution for ancient ancestors because we must factor in the environment that the organism lives in. The nature vs. nurture argument as well as epigenomics suggest that the environment plays a crucial role in our development as well as evolution.
It certainly is interesting in being able to discover prehistoric fossils with modern technology but I believe that the practical application in this whole process will be how we observe the differences in genetics of animals and humans in the past compared to today. By observing the changes of the human DNA or animal DNA in the past, we can make hypotheses and inferences about how the genome developed and it will eventually develop in the future.
ReplyDeleteThe obvious limitation in discovering old fossils are preservation of these fossils due to the deterioration of DNA over time. In this case, genomic sequencing is one of our current primary way of determining how organisms evolved and are related. By employing the use of what we know today in the human genome, we can easily decipher the changes DNA has undergone in each time period.
This is an incredible feat for the science community. Being able to figure out the genome of our ancestors could lead to many breakthroughs in the study of evolution, how we adapt, etc. It is truly incredible, and could lead to so many breakthroughs in science. However, there are some issues with the process. If we were to do this same thing with humans, it would be hard to treat this like a normal study because you could never get consent from the older specimens. There are also ethical issues with perfecting the system--for example, figuring out what temperature the DNA needs to be frozen at could result in damaged DNA (until they figure out the perfect temperature). Advancements in science will eventually lead to older mapping methods becoming obsolete. In considering this method to become more regularly used, the benefits must outweigh the consequences.
ReplyDeleteI found this article to be very interesting and could lead to some great, future achievements for the science community. I think that using DNA from assumed ancestors of the older species is a good way to fill in the gaps in sequencing DNA from prehistoric fossils. This way of completing the puzzle could also lead to discoveries about evolution that would not have necessarily been found with out DNA sequencing. When comparing the DNA sequences it will be easy to spot differences between the two and figure out what changed in the sequence in order to cause a change in phenotype.
ReplyDeleteAs mentioned above, the limitations of this method would of course be preservation of the DNA of prehistoric beings. As spoken about in the article, one of the main reasons why the DNA of the 700,000 year old horse was able to be preserved so well was due to the cold climate. Other species' DNA might not be able to avoid rapid destruction as well. Also, ethical issues could arise when trying to compare human ancestors' DNA with modern human DNA. However, I still think it would be extremely interesting to trace our evolution through DNA sequencing, and it would probably be the secret to unlocking many unanswered questions.
It is amazing that frozen temperatures could preserve the DNA, and also amazing that modern technology allows us for such a scientific achievement. I think the methods behind piecing together the sequence until completion with the use of the related ancestors is extremely interesting. I also feel that it could be easy to make error by doing guesswork as if you’re piecing together a puzzle. Though the methodology is questionable because of how much room for error it leaves, it is still remarkable. It opens doors for many more scientific discoveries. Genomic sequencing using live animals to relate to the prehistoric ancestors could also be inaccurate because the genetic changes that the current ancestor has undergone through evolution could be so drastic to the genetic information. As technology progresses it will be interesting to see where science goes and what is in store for the future.
ReplyDeleteI think the article was really interesting, and I think it is so cool that scientists were able to determine the genetic sequence for an animal over 700,000 years old! However, I do think there are many limitations to the method discussed in the article. For example, many of the organisms that may be of interest to the scientists in the future might not be preserved by cold climates. Therefore, the DNA might be more degraded and harder to sequence.
ReplyDeleteI also agree with Caitlyn's statement that using live animals to relate to prehistoric ancestors could be limiting because of such drastic evolutionary changes in the genes. For example, there could be huge deletions, mutations, insertions, and epigenetic modifications (histone modifiations, methylation, etc) that could complicate the accuracy of sequencing the historic organism's genome.
However, I think the advancements in genomic sequencing could be really useful in uncovering the link between monkeys and humans genomes. It could be possible to trace our evolutionary differences to specific changes in DNA sequences. However, ethical questions will arise if we start to use current human DNA to compare it with ancestral DNA, such as the issues of informed consent and storing the DNA for future studies. Also, I see using human DNA to resurrect an extinct species as clearly unethical. The focus of the research should be on understanding the evolutionary relationships between species, and understanding how we got from Homo heidelbergensis to modern humans, not trying to recreate a species from the past; evolutionary changes happen for a reason.
Using DNA sequences of ancestrally related species to piece together ancient genomes represents a creative and brilliant way of revealing what life looked like in the distant past. However, there are limitations to this practice. When using the genome belonging to a species currently alive as a template for an ancient relative, the current template clearly will not contain the same sequence. Thus using constructed genomes of other ancient species provides a more accurate method of obtaining template sequences. The use of different species from different time periods creates a more representative and dynamic genomic template that can assist researchers in constructing ancient genomes.
ReplyDeleteSimilar techniques can be used to complete the genomes for our own ancestors; however, the genomes that are constructed should not be taken to be absolutely accurate. I don’t see anything wrong with constructing ancient hominoid genomes as they can help begin offering partial answers to such questions as, “Where did we come from?”
Traditional methods for mapping ancestry between species, such as the study of morphological, including skeletal, constructs are still useful. But as next generation sequencing makes whole genome sequencing cheaper, more reliable, and faster, such techniques will likely become out-dated. They can still; however, provide useful visual representations and clues to how the genetic code becomes phenotypically expressed. I believe genomic sequencing will become the one of the most important tools in determining the evolution of organisms, but studies on animal behavior and examination of organisms remains will continue to play a vital role in explaining what the sequences in an organism’s genome are translated to everyday life.
As technology advances further and further, it comes as no surprise that scientific limits and records are being pushed farther. As for dealing with prehistoric DNA samples, I feel that some of the battle involves luck – for example, the fact that the temperatures were cold enough to slow the degradation of the DNA was extremely fortunate, or else sequencing the genome may not have been possible. In terms of using related specimens to the assumed ancestor as a reference for the sequence, I would approach the analysis and data with caution. In order to be convinced by the reliability of the data I would of course want to read the original article to see how the researchers chose the related specimens, how they adjusted for discrepancies, etc. At the same time, I understand that dealing with prehistoric samples imposes a variety of limitations, which start with damaged and fragile DNA samples. If the sample that you are working with is itself so difficult to handle, then you are limited to referencing sequences of related species to fill in the blanks.
ReplyDeleteWhile science and technology continues to progress, I think the older traditional methods for mapping related organisms will be improved upon to be made more efficient – but I wouldn’t say that they will become obsolete. Science builds on itself, and though technology may make a method faster and more accurate, the basic concept is likely the same. I don’t think genomic sequencing will be the sole method for determining how organisms evolved and are related. Currently many other methods exist – studying vestigial and homologous structures, investigating embryonic development, and so much more. If anything, I feel these other approaches to studying evolution will also advance along with genomic sequencing.
I feel as though DNA sequencing to determine ancestors and relationships between specimens today and in history is a great method to determine general, small relationships, but I don't think it should be used a sole method to determine who is whose ancestor. There are a lot of technical issues that could go wrong in genetic sequencing, mainly because of how small each component of a sequence is. It is very easy to miss something tiny that, as we know, can result in a HUGE change in a phenotype. I think DNA sequencing/freezing DNA is a great outline and guide to figuring out new relationships to our past and to help decipher new theories of evolution, but we should use other ways to ultimately determine finalized theories.
ReplyDeleteIn genomic sequencing, this study clearly showed a huge leap. However, the information is somewhat useless unless it is compared to a reference. This is why I believe that using the genomes of similar species as references makes sense. Not only this, but it also allows for new discoveries such as learning that Przewalski's horse is from a different “branch” of equines than domesticated horses. I think that this is an important realization for human-related applications. In sequencing ancient hominid DNA, it may be possible to create a clearer and more well-defined ancestry line between humans and other species. However, as the article did point out, this method may not be applicable to humans, but it does offer hope and new research opportunities. I do not think that other methods for mapping organisms will become obsolete, but I do think that ancient genomic sequencing will greatly advance the current methods used. As I pointed out earlier, related species’ genomes are very helpful for referencing. Without other techniques outside of genomic sequencing, related species may not be easily determined and certainly wouldn’t be if we hadn’t been able to already learn so much about evolution. This is why I would conclude that genomic sequencing of ancient organisms will greatly assist the current techniques for determining evolution and the findings from related research thus far will lead to many new opportunities in related subjects in the future.
ReplyDeleteAll other considerations aside, I am absolutely amazed that the team at the University of Copenhagen was even able to extract DNA from such an old sample at all (preserved in ice or not). However, it is my duty as a lover of science to be skeptical of the full genomic sequence which they have presented as belonging to the equine ancestor whose remains were recovered in the Yukon. Their use of reference sequences from modern equine (horses, donkeys, etc.) to help fill in the holes of the genome of the Equus lambei, whose own DNA had degraded over hundreds of thousands of years despite having been frozen for so long, was a clever idea and provided a good foundation from which to work off of. While I’m sure that the geneticists themselves would have preferred to have found a complete sample thereby eliminating the risk of making false assumptions when it came to deciding which portions of the modern equine DNA belonged in the lambei’s genome, the work that they were able to do with the materials and technology available is still nothing short of astounding. In the future, I think that genomic sequencing will be used more frequently in conjunction with more traditional methods of determining evolutionary relationships between organisms, but I do not think that the classical methods will ever disappear altogether because while genomic sequencing is a technological marvel there is still something to be said for good old fashioned detective work and problem solving.
ReplyDeleteAfter reading the posted article, the first thought was of how using the technique of finding patterns among related genomes and species to identify the found DNA was a unique and inventive process. The researchers at the University of Copenhagen exhausted their critical thinking skills and solved a complex puzzle with a strong background in genomics. However, in this instance, I do believe the study team was fortunate to have samples of related equines otherwise they might have had more difficulty. Thus, limitations do and will exist for future studies.
ReplyDeleteFor example, location is a key part to the research. The leg bone of the 700,000 year old horse was dug up in the Yukon Territory of Canada, offering a perfect climate to preserve the fragmented DNA. If the leg bone was to be found somewhere other than the cold and icy territory of Canada, then the preservation most likely would not have happened. As well, what if the bone was extremely rare and had few related species or relevant DNA samples to draw from? A halt in progress would have occurred.
With these limitations I am led to believe that using genome examination to determine the evolution of a species will not be the sole technique. The older ways of discovering patterns and relating organisms will not simply vanish, but rather hold strong in this world of increasing advanced technology.
I think that reconstructing DNA into a pattern is a skeptical process in itself. First off, the DNA fragments are assumed to be all from the same animal and that no fragments have been completely degenerated or lost. This “puzzle” of recreating fragments of DNA seems to be putting the cart in front of the horse because the technology for DNA sequencing seems to still be in its infancy. I think this application is moving too quickly for the technology available, and the current knowledge we have on the subject. Also, using DNA assumed to be related appears extremely suspicious, and a research model that is taking shots in the dark. The recovery of prehistoric DNA also seems to be quite an ambiguous venture, and I am apprehensive to believe that full DNA sequences could be found or reconstructed especially given that the 700,000-year-old DNA found in perfect preserving conditions was fragmented to a significant extent. In addition, even if using sequences that are assumed to be related was a concrete design, all closely related species might have gone extinct as well. The advancement of this field could take over, and make the mapping related organisms and their evolution obsolete if the data can be extrapolated in that way. I am not sure if it can become the sole method because there are other factors that would be needed to assist in providing context to the findings in DNA.
ReplyDelete
DeleteThis discovery involved the use of another specimen’s DNA as a reference for the ancient DNA fragments. This seems like a possible source of error and involves a certain level of assumption. The scientists assumed that the horse genome would be most similar to the ancient one they discovered. It is incredible that the entire ancient genome remained so intact. It was mentioned that the genome had not degraded due to the ice but rather was fragmented. This discovery was so rare and therefore it is unlikely that sequencing similar has been done in the past. The ability of these scientists to so accurately sequence the fragmented genome shows the progress that has been made in this area of genetics. As science progresses perhaps it will be possible to sequence DNA that is even less complete than that of this specimen.
ReplyDeleteThe fact that scientist were able to complete the sequence of horse remains from 700,000 years ago is incredible. I found it interesting that cold temperatures were able to slow down the degradation of the DNA by so many years. Although I thought it was a great idea to use the genome of a modern horse as a reference for sequencing the ancient horse, I don't think that we can ever be completely sure that the DNA sequence matches up. I am a little skeptical about the methods of "piecing together the puzzle", but yet at the same time I feel that using a reference sample is the most accurate way out of other possible methods, so I am impressed with this new finding. One limitation of using prehistoric samples is that the DNA is so fragile and therefore difficult to work with. I believe we should never rely on one method to map related organisms, and scientists will continue to use their traditional methods in addition to the DNA sequencing.
ReplyDeleteThis article is very interesting and the fact that scientists were able to genetically sequence a 700,000 year-old ancestor to the modern horse is momentous because that significantly surpasses the previous oldest fossils to be sequenced by hundreds of thousands of years. This drastic improvement shows that science is progressing faster and faster these days with the help of technological advancements and more developed methods of research. Although this method has many limitations, it serves as a much stronger foundation for understanding our ancestors. Previously scientists relied heavily on an organism’s phenotypic makeup, including bone structure and physical characteristics, to determine ancestral linkages. Using genetic sequences and DNA specimens as a reference to study the genome of ancient animals and their relation to modern species provides a strong foundation for research. Having the ability to examine an organisms DNA is valuable because it gives us the evidence of mutations that occurred in the genome to bring about adaptations in the species. However, genetic sequencing may not always work because many adaptations occurred because of epigenetic factors such as environment and dietary needs. Keeping this in mind, this discovery is still a tremendous breakthrough in science and should be recognized for this achievement.
ReplyDeleteThe distant past has the potential to be a large source of frustration for many areas of research. Historians, anthropologists, and biologists (to name a few) all probably wonder how much different their fields would be if the populations of eons ago had the capability of preserving themselves in the way that we do today. However, as our present technology increases, some of those knowledge gaps that exist are able to be addressed. The article that Professor Chan posted is an example of this.
ReplyDeleteAs other students have mentioned, genomics is not simply the sequence of nucleotides that comprise a DNA strand. There is more to understanding how an organism lived than just to understand its chromosomal make-up. We learned in class how many different factors can affect how DNA is utilized and presented. Therefore, it would be a fallacy to believe that genomic sequencing should become the sole way of understanding these ancient organisms. However, it can become an incredibly useful source, when in combination with other disciples of research, can help us to understand the complexities of the past.
The world will benefit from this technology, but in examples where serendipity is a little less present, we will need to rely on our other tools at solving the mysteries of the past.
This article had some fascinating news that many others and I thought could never be done. To be able to extract the DNA from 700,000 years ago is incredible and very noteworthy however how safe is it to go any farther back? As they stated, DNA starts to degrade instantly and only small amounts remain in broken pieces, making it hard to put any of the pieces together. Using a reference guide to put the genome back together, I think is a good idea but only to a certain extent. The animal needs to be closely related and they need to make sure that that DNA was sequenced correctly as well. As long as those are met, the genome can be sequenced to a pretty far degree. Some limitations are that DNA does breakdown fairly quickly and unless it is preserved in ice, it could be hard to get the DNA from something older than 700,000 years ago. Genomic sequencing I don’t think could be the sole method for determining how organisms evolve because it is fairly new with data no later than 700,000. If we are able to move into humans and others organisms then this could definitely become the main method however for now I don’t think it will be that easy to gather DNA older than we already have unless it has been preserved.
ReplyDeleteIt is fascinating how modern technology gives us the ability to use current DNA as a reference to recover ancient genome that dates back to 700,000 years ago. And with this strategy, we could possibly recover DNA from ancestral human species and finally connect the human family tree. However, I agree with Nicole that it would be much harder to extract information from humans because of difficulty in obtaining human DNA and ethical issues like consent. Also, as mentioned in the article, the genome of the 700,000 year old horse was preserved due to the cold weather. Preservation of DNA is a big limitation. But with our technological advancement, I believe that one day we could trace back to our original ancestor.
ReplyDeleteI’m very intrigued by this article and furthermore, impressed by the advancements in technology that have contributed to the sequencing of this 700,000 year old horse. It’s amazing to think about how far genetic research has come in such a short period of time. I’m curious to know more details about the whole identification process, especially because I don’t understand how they knew to use a modern horse genome as a reference sequence. The article states that a leg bone was used as the source of DNA extraction so how did researchers determine that the leg bone belonged to this particular ancient horse and not some other unknown species? I’m sure there is and quick and easy answer, but it is unclear in the article and thus, a point of confusion for me.
ReplyDeleteDespite my skepticism, I think the use of reference genomes is incredibly useful and efficient. As Alex and other students mentioned, I don’t think that sequencing alone is enough to understand how organisms evolve; however, I think as technology advances, we will discover new techniques that incorporate and enhance the traditional methods, allowing for a more holistic view of an organism’s function and development over time.
Using the DNA of other specimens assumed to be related to an ancient ancestor is, in my opinion, a very smart and systematic method for discovering where an ancient ancestor fits into our history of evolution. Without doing this, it would be hard to know where to begin when fitting the “puzzle” of the ancestor’s genome back together; using DNA of other specimens assumed to be related to the ancient sample is a perfect starting point from which to begin the sequencing. If this same principle were applied to prehistoric hominid DNA, it would be important for researchers to consider whether or not the ancient specimen was more closely related to modern humans or modern apes when choosing a modern DNA sample to compare the ancient sample to; also, obtaining a human DNA sample to compare the hominid DNA sample to could potentially be difficult when selecting what race, gender, etc. to collect DNA from, as well as for privacy and confidentiality reasons. Using this methods of DNA sequencing could make traditional mapping of related organisms based on phenotype/appearance obsolete. I believe that with further refinement, genome sequencing can become the sole method for determining how organisms evolve and how all organisms are related.
ReplyDeleteShanika Gilmour
I think it is amazing that scientists could fully recover DNA of an organism that lived so long ago. While it has been fully recovered, there was obviously some room for interpretation since the scientists used modern equine DNA as reference. I think one of the major limitations is that modern ancestors of the organism have evolved so much, and this could possibly cause misinterpretation as to what the original DNA sequence was. As technology and scientific methods improve, I do believe that genomic sequencing can be used to determine how organisms have evolved and are related. This example is a small insight into what genomic sequencing will eventually become.
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ReplyDeleteThe fact that this 700,000 year old "horse" had maintained it's DNA because it was frozen provides that it is extremely difficult to sequence DNA that is very old. The fact that the horse still maintained it's DNA was lucky. In order to sequence such a fossil, the organism would have to have been frozen relatively quickly after it had died, thus keeping the DNA still intact. The technology that we have today to be able to sequence such a fossil is incredible. The amount of information that we can gather can benefit the scientific community (as well as other communities) in that it is able to clarify and provide factual information of where exactly that organism belonged in the biological classification.
ReplyDeleteIf sequencing becomes a more cheap, available, and quicker option, this method will definitely dominate when dating fossils. Carbon-dating has been the most current method for putting a timestamp on fossils however the accuracy is less than genome sequencing.
As scientists continue to provide more accurate knowledge of our ancestors, our knowledge of the timeline of Earth will become more accurate which can provide us on clues about the future. Overall, the process of genome sequencing is continuing to advance and as technology improves, the efficiency will also advance thus expanding the knowledge in the scientific community.
First off, the very idea that scientists are now able to fully recover DNA and sequence the genomes of ancient species is mindboggling. Scientists previously thought that it would be impossible to recover an ancient genome due to how quickly DNA degrades. Goes to show that science will never cease to educate, amaze and conquer the (seemingly) impossible. I think it is not only a monumental step in technological advancement, but more importantly, it is a major stepping stone to better understanding ourselves, the human species, on a level that has never before been explored. Though of course there are limitations, and it is because of these limitations that I don’t think genomic sequencing should become the only method for determining the origin and relation of organisms. As Church explained, one limitation is that this type of genome resurrection technology may not be applicable to all species. Another possible limitation is finding model genomes to work off of in re-sequencing the ancient genome, as was done with the modern horse genome. Additionally, the present genomes may not necessarily match with the past genomes, leaving room for analytical error and interpretation. One of the first disadvantages to this new sequencing mechanism is much, much further down the road, in the most drastic of scenarios, we could find ourselves in a Jurassic Park situation. Good intentions may lead to unforeseen, accidental consequences. This begs a couple of questions. First, should the past be left behind, or is it worth digging up and bringing back to life? Second, what functional purpose in society would reviving ancient species play? This was a very fascinating and intriguing article/concept.
ReplyDeleteThis finding is incredible! So previously scientists hypothesized, or even maybe assumed, that recovering genetic info from DNA that's millions of years old would obviously be impossible because of how quickly DNA degrades after the death of an organism. But now we KNOW that it is possible to recover a species's genome from such an old sample.
ReplyDeleteAs technology advances we as a species broaden our horizons, become more open-minded, find new questions to ask, challenge what we know in more ways, and learn new things that previously seemed absurd or impossible. This finding means that there is hope to finding more old, frozen DNA of our human ancestors... helping us fill in the gaps in our knowledge of how we got from where we were to where we stand today. Studying the genomes of other species is important. We can observe evolution from an objective standpoint and in studying ancient species, learn about how life was way back when. Seeing how evolution plays out in other species, we can apply that information to studying human species. After all, we are just really smart animals. We aren't immune to evolution. – And if we can't find DNA from direct cousins of homo sapiens, maybe we can find DNA of other closely related species in hopes to shed light on how we can to be the species we are today, and how our ancestors' lives still hold impact on us today, genetically.
Hindsight is 20/20. Looking back helps us on so many levels. We can learn what our ancestors did wrong, and what they did right. And how that led to homo sapiens. I think it's SO important to look back and see what was. If it were somehow possible to know everything about out ancestors and our past, we would be able to make much better use of our genetics codes, and learn so much more about why we have the genes we have. Knowing how genes changed with time, and which ones stayed, and why is the key to understanding the direction our evolution is going and to learning how to read our genes in a more sure-fire way. I mean maybe one day we will be able to tell if someone is getting a certain genetic disorder and exactly when, versus being able to tell that he/she has a predisposition to getting that disorder or is a carrier for it.
I am immediately completely amazed that scientists believe they could possibly resurrect a species from 700,000 years ago. This is incredible. Although for me it brings up a question about whether we should go through with stuff like this. The information that could be gained through genome sequencing of a species this old would in invaluable, however recreating a species that has been extinct for years? This seems to me like it is potentially just asking for trouble.
ReplyDeleteIn terms of sequencing DNA from prehistoric hominids, I think that this information could be helpful as long as the information is interpreted cautiously. There really is no way to know for sure that the genome has been sequenced accurately when comparing to a species that scientists are assuming is related. I think this is an incredible scientific breakthrough, but it leaves a lot of room for error.
In terms of traditional methods for mapping related organisms becoming obsolete, I think this is inevitable. Technology is advancing so quickly, older ways of doing all kinds of things become obsolete just as quickly, and it makes sense that this would happen with mapping evolution as well. As we develop more efficient, cost effective ways to do this, of course the old ways will become obsolete.
I think genomic sequencing could become the sole method for determining how organisms evolve and are related but I think that it would be smart for scientists to continue to look for and at other ways of studying this. Being able to cross check new information with other methods will ensure more accurate results.
This is a very exciting article and the discovered ability to sequence such old DNA is absolutely incredible.
Although it is remarkable that scientists were able to sequence the genome of a 700,000 year old horse, I think the aspirations of Harvard geneticist George Church are ridiculous. I do not foresee any good reasons for wanting to resurrect species that have gone extinct hundreds of thousands of years ago. From an evolutionary perspective, these creatures went extinct for a reason and bringing them back by pasting their genes into the genome of their living relatives would cause chaos in the natural habitats and ecosystems that already exist. I think it is foolish to want to do anything like that because it would throw everything off balance in the natural world.
ReplyDeleteI think that genetic sequencing for clearing up specific family trees is a great idea but I would strongly caution against getting too crazy with it. If the DNA isn't too fragmented and if it is possible to get a clear picture from sequencing fossils then I'm all for it. But if people are going to start haphazardly "resurrecting" certain species without thinking of the consequences, then I think that it is a foolish method to pursue.
Even though the findings of this article are truly remarkable and life changing I don't think these scientists should be in the business of resurrecting extinct ancient species. There's a reason they're ancient and extinct; evolution and natural selection did not allow for them to keep living as the earth's climate evolved and changed. I don't think they should be trying to resurrect animals that may not be able to live freely now because there is just no where for them to live on the present earth. I don't think they should be resurrected just to be kept in captivity and studied.
ReplyDeleteI think that if it's necessary to reference other specimens that are assumed to be related to the ancestor then scientists should do so. I'm a little worried about mistakes though like what happens if they think the specimen is related and it ends up being that they're actually not. How can they be sure that the specimens are related??
I do think that DNA sequencing is the only way to ensure accurate family trees and phylogenetic trees because that's what a genome is, our shared inheritance. I think it's important to map the human ancestry because it's good to know where we came from. It would solve so many ethical questions and put so many debates at rest for a really long time.
I found it very remarkable that scientists were able to sequence the genome of an animal that was this old. Its amazing that DNA can be preserved for so long, even if only partially, and that modern technology has allowed us to rebuild the puzzle. While it does involve a bit of guesswork, if scientists can use reference points of other animal ancestors, they can begin to get a much better understanding of where modern animals evolved from. While it clearly cannot solve the mystery evolution completely, it can definitely point some theories in the right direction. In terms of genome sequencing techniques, in recent times, science is advancing so quickly that it is inevitable that many techniques will become obsolete. We keep coming up with better and better ways to sequence DNA and the sky is the limit in terms of what we can do with this technology.
ReplyDeleteIt is very interesting to see that the whole genome of a 700,000 year old horse was sequenced. I support the genome sequencing of extinct species, but I also don't see a need to resurrect them. The only benefit from resurrecting species is to increase our knowledge and learn more about them. However, what other benefits do we get from just resurrecting ancient species. Within the next few years, our technology will continue to advance so old traditional mapping methods will eventually become obsolete. In addition, although it may seem that genomic sequencing may be the sole method of determining how organism evolve or are related, I think our advances in technology will allow for other methods that might have a better impact. Genomic sequencing will continue to improve as well as other methods.
ReplyDeleteIt is amazing that we were able to recover DNA from 700,000 years ago. Technology is advancing so fast! The fact that we may be able to recover DNA from prehistoric hominids is mind-blowing! With this information, we could map out the entire human species. It may be difficult to obtain human DNA because there are many ethical issues. However, as Elizabeth said, I do not believe that scientists should be resurrecting extinct species. I agree that these species are extinct because of evolution and natural selection. The earth has evolved so much that it would be a completely different environment for these extinct species and they would not survive. As technology continues to progress, I am curious to see what other advancements scientists discover.
ReplyDeleteNext-generation sequencing has enabled the sequencing of ancient DNA samples, and has widened the scope of metagenomic analysis of samples derived from nature. It has made it possible to sample the nuclear genome of ancient remains from various mammals. The article above discusses an anecdotal example of the application of next-generation sequencing in the field of genomics. The fact that scientists were recently able to fully sequenced the DNA 700,000 year-old ancestor to the modern horse is truly incredible.
ReplyDeleteThere were particular circumstances that allowed this discovery to occur. DNA typically degrades after an organism dies, which makes it increasingly difficult to piece back together its genome. However, in the case of the horse, the environment where the genome was buried was particularly cold, as it was found in permafrost. These cold temperatures slowed the degradation of DNA, allowing the scientists to more easily piece the horse’s genome together. Naturally, this discovery has led scientists to feel optimistic about the possibility of sequencing the full genomes of other species, such as hominids. Unfortunately, the methods used for sequencing the horse genome may not be applicable to other sequencing genomes of other species. There were specific environmental conditions that allowed the horse genome to be sequenced, but these same conditions may not be present when attempting to sequence hominid genomes. In short, hominid genomes are less likely to be found in very cold environments. Because we are more likely to find hominid genomes in warmer environments, the DNA from their genomes will likely be more degraded than that of the horse’s genome. This is a major limitation when considering the probability of successfully sequencing a hominid genome using solely the methods that were used to discover the horse genome.
I think the ability to sequence partially degraded DNA to create a whole genome sequence of a being that has long been extinct is an amazing development for the science community. On that note though, I have to question the limitations of this method and its viability in the future. While the variety of reference species helped to create the genomic sequece, I have to wonder if any major differences were overlooked or missed because of this. I would not be surprised to find out later on that there were errors made in the sequencing. I also have to wonder about how useful this method would be in the future. As many have already pointed out, we would need closely related descendants to sequence a specimen's fragmented DNA so we could only extend this technique so far back. I do think it would be helpful in sequencing hominoids and creating a clearer picture of homo sapiens' ancestry. I cannot imagine a time when genomic sequencing could be obsolete but I wouldn't go as far as to say its impossible. I think the improvements we make to the technique in the future will likely make it unrecognizable from the techniques today.
ReplyDeleteThe implications of genomic sequencing are extraordinary. I am really amazed that scientists were able to sequence an entire genome from 700,000. And from that information they were able to extrapolate the ancestors of a modern type of horse. Although the article mentioned some limitations including environmental degradation of the DNA, this type of sequencing can be further applied to other ancient organisms. Knowing the genetic sequence can provide a lot of useful information, but I do not think it will replace other methods of determining organism evolution. The sequence can determine some things, but will not show you how the genes are expressed. Therefore fossil excavation and examination may still be really important.
ReplyDeleteIt's incredible how scientists are able to piece together fragments of DNA that is almost a million years old! It's also brilliant that they are able to compare the DNA sequence to that of zebras, horses, and donkeys to test their acuity and find the perfect match for the newly discovered sequence. As genomic sequencing evolves and becomes more refined I believe it will take over all other methods of distinguishing between relative species. It is a complex yet telling method to compare species that has so far been in our favor! However, scientists in the future should try not to overreach beyond their capabilities with the limited data they have at hand. For example if they found other segmented DNA samples and couldn't find a match to any animals they shouldn't just guess and relate it to the closest animal they can find. They should wait until the technologies for this kind of work sharpens
ReplyDeleteI feel a little skeptical about the reconstruction of this old DNA sequence and comparing it to species today. It is extraordinary that science has progressed to be able to do such comparisons but I believe that while the animals may be similar, if there is not a complete sequence, they cannot "resurrect this 700,000 year old horse."I think that I could be thinking this way because I am some what cynical when it comes to some theories of evolution. It is very cool that the broken DNA can be compared/contrasted to zebras, donkeys, and other horse species but my question is, what are the pieces they are missing in the DNA? Also, to resurrect the 700,000 year old horse, they would need to understand the epigenetics to determine how the genes were modified by its environment. I am not quite sure if I am completely answering the questions asked, but I guess I needed to voice that I am skeptical of such studies. Perhaps in the future I will be more convinced when further studies come out that they have completed a DNA set for animals who lived long ago. It will be interesting to see when extinct animals are found and scientists do not know what family of animals they belong to. Then the DNA sequenced could tell so much more about the ancient world that we have yet to understand.
ReplyDeleteThis method of sequencing genomes from other organisms is a fascinating example of how far technology has brought us. It’s exciting to think about how these methods could eventfully allow us to sequence ancient human genomes as well. So much will be discovered about evolution and inheritance, allowing us to learn even more about our modern day selves.
ReplyDeleteUnfortunately, timing presents a limitation. Since DNA deteriorates over time, it will be increasingly difficult to accurately sequence the most ancient species. It would be beneficial to look at the oldest species, because they will give us extremely valuable information about how nature has come to be what it is.
The possibility of resurrecting ancient genomes is fascinating as well as a bit creepy. Bringing organisms back from extinction poses a lot of issues. Bringing back an extinct animal species would be wonderful, especially species that have died out due to human intervention. However, what if resurrecting human species becomes a possibility as well? This could bring up problems like autonomy, as mentioned before. There are countless additional problems that could arise, such as how to monitor who and what will get resurrected, and who will get to make those decisions. This idea of resurrecting reminds me of cloning, I feel like they both have similar ethical implications. This technology has the possibility to make an incredible impact on the world; we just need to keep in mind the best interests of all species, both dead and alive.
The fact that such ancient DNA can be sequenced now is absolutely fascinating. Technology has enabled scientists to make so many connections and piece together the ancestry of organisms. DNA sequencing is a valuable tool which tells us much about the past, and about the future. One thing to consider when sequencing old DNA using newer matches is the possibility of evolution and changes over time. Although an organism may look and act the same, the genetic makeup could have varied quite a bit. Also, the epigenetic factors which could have altered the old DNA may be different than they are today. The time elapsed between the formation of the DNA and its discovery years later have an effect on the structure of the DNA, and that's difficult to identify in some cases.
ReplyDeleteTraditional methods of DNA sequencing could become obsolete as technological advances surpass previous tedious processes of DNA matching. Perhaps eventually, new technology for DNA sequencing will be utilized in all aspects of the field, including for old specimens. The article claims that it can "resurrect a 70,000 year old horse", but I'm not sure that's entirely possible, considering how old the DNA is and how different the species could be now. It's an interesting phenomenon to consider that we could have just as much genetic information about a horse today and a horse that lived 70,000 years ago. But how does this help us progress through science today? What does knowing the genetic makeup of a 70,000 year old horse tell us? It's a question of using resources and time to reconstruct and sequence DNA which may not even relate to current times. It doesn't promise a groundbreaking discovery, but it does help piece together the past, and to better describe the process of evolution for certain organisms. Only time will tell of DNA sequencing's actual efficiency for ancient DNA samples.
I thought this article was really interesting, but also somewhat hard for me to grasp because I do not have a big background in genetics. It was fascinating that the DNA of the horse was preserved in the ice and that genetic technology is so advanced that it was able to fully sequence it. However, this is also a major limitation, as I would assume that it is pretty rare that DNA would be preserved so well. When it comes to “putting the pieces back together,” it seems like the process is very much an experimental, “hit or miss” process. While it would be interesting to sequence prehistoric human species, I think this experimental aspect should be taken into account and seen as a limitation. Because of this, I do not think that genomic sequencing should become the sole method for determining how organisms evolve and are related.
ReplyDeleteIt is fascinating that scientists were able to reconstruct a 700000 horse DNA. Genetic technology certainly has advanced very far. To me, this project was important because we might be able to bring back animals that have become extinct due to human encroachment. We may be able to revert some of the ecological damages and reintroduce native species. However, we still have a long way to go. The researchers were able to replicate the DNA because the bone was in permafrost. If the horse wasn't frozen, there is no guarantee that they were able to recreate the DNA sequence. On the other hand, we have made big advancements in genetics. I am excited to see how technology can change our lives in the near future.
ReplyDeleteI think it is incredible that with today’s technology, we are able to sequence the genome of a 700,000 year old horse. This is a huge advancement compared to our last prehistoric genome sequencing of a 120,000 year old polar bear fossil. However, while this was a very commendable feat, there still seem to be limitations to the accuracy of sequencing. For one thing, the genome of the 700,000 year old horse was still fragmented and was only able to be completely sequenced after being compared to other common ancestors which will have variably different sequences and are only assumed and not definite, for the 700,000 year old horse. These references may not always be accurate especially when their time periods of existence are fairly wide apart. Furthermore, obtaining DNA that is adequately preserved in other prehistoric DNA is not always feasible and very limited.
ReplyDeleteThese gaps in scientific knowledge and data cannot provide a fully accurate picture of how organisms are definitively related because most of it can only be assumed at the very end. Thus, genomic sequencing technology is still not strong enough just yet, to become the sole method for determining related organisms and their evolution. However, with the increasing capacity of genomic sequencing, the use of older methods such as genomic mapping will probably diminish as improvements in genomic sequencing provide us with more opportunities that we never imagined we'd come across.
The success of this study may have implications for wider research. The new techniques that successful sequenced this gene may be applied to many more fossils, up to 1 million years old, and give us key insights into the evolution of many species, including our own. The oldest previous sequenced DNA was *only* 75,000 years old, so this is a major breaking of time barriers.
ReplyDeleteI think that using modern species as references for their ancestors is not a bad idea but there are several issues that would need to be overcome. For starters, these animals are extinct and there is probably a reason for that beyond being hunted to extinction or something like that. Chances are there was sequencing in their genetic code that prevented them from adapting fast enough to the changing environment to survive. A scientist will not find these sequences in their modern day relatives so that will leave potentially alot of guess work for scientists trying to map this entire sequence. I think there is merit to using modern DNA as a reference but I think its folly to think that the entire genetic code can be mapped out exactly how it was when this animal died.
ReplyDeleteIf this is to be done with ancient humanoid DNA I think similar issues would arise. Just because they are related does not mean we are going to remap that ancient DNA with out modifying it a bit or leaving parts of the sequence blank. In terms of determining general evolution though I think this type of reconstructive mapping will be very effective.
I do not think that genomics can be the sole determination of evolution, as mentioned in the article, DNA begins to decay immediately after death, so without a reference for the DNA being sequenced, ie modern relatives or reference relatives that are extinct, there would be huge gaps in the DNA at the very best. Most likely though the "puzzle" would never be able to be put back together. Much like the scenario of Humpty Dumpty when all the kings horses and all the kings men couldn't put him back together again.
First and foremost, this article reminds me of the extrapolation that DNA can last only 6.8 million years, even in ideal temperatures for preservation, making a Jurassic Park cloning fantasy painfully impossible as the youngest of dinosaurs existed 65 million years ago. However, this does implicate that, under ideal conditions, the DNA of an organism from 6.8 million years ago could be found and sequenced. If we can make a successful jump in sequencing from 120,000 years to 700,000 years then our ceiling still needs to be determined.
ReplyDeleteSo we could potentially go back those 6.8 million years for a sufficient DNA sample and, much like this ancient horse, require modern day relatives to complete the genome sequence. Then, if a perfect, intact sample of that same organism were also found, it could be compared to the reconstruction and we could see just how accurate our technologies and methods are.
I think it is perfectly logical to use DNA of related species to help determine the genomic sequence of extinct organisms. We know that the diversity of genomes between species is remarkably little. For example, we share at least 90% of DNA with monkeys, our closest known ancestor. With fossilized DNA, I would imagine that you run into the risk of it being corrupted in some way. It is possible that genomic sequencing may overtake other methods for determining how old organisms are, but I do not think that it is likely. It is usually beneficial to use a variety of methods when gathering scientific data.
ReplyDeleteOn a different note, I would really like to see these extinct species be brought back. How cool would it be to be able to see a T-Rex or one of those giant sloth-bears?
This article was very interesting. It's pretty impressive that the record for the oldest sequenced genome was beaten by such a large margin. It sounds like the events leading up to making the 700,000 year old horse's DNA useable were both very specific and very rare. The reliance on presumably related animals' genomes to complete these ancient genomes raises some issues. Such as: will we completely know for sure that these newly sequenced genomes are authentic to the genomes from thousands of years ago? It seems entirely reliant on our presumption that these are in fact relatives of these ancient animals.
ReplyDeleteIt seems that so much stands on whether or not our assumption of relation is correct. As technology increases, however, we may be able to make more accurate assumptions and truer genomic sequences of these animals. I mean, the oldest sequenced genome had only been 120,000 years--and it was just blown out of the water by this 700,000 year record. Technology is always advancing, and with it, so does our knowledge.
As many of my peers have already brought up, there are some ethical concerns regarding the usage of DNA specimens as references for sequence completion. While we may only be exploring the DNAs of animals at first, this begs the question of where we will draw the line in the future. What is to say we will not take it a step further, and implore into the rights of our dead ancestors, both recent and not so recent? Just as Gianna has mentioned, it is easy to overlook the fact that they never signed that right over to us. Even in the name of science, we should not ignore these ethical implications. In addition, as Sofia and many others have mentioned, there is a lot of guesswork involved in using "related" DNAs. There are a lot of gaps and differences in DNAs, and we can only make assumptions in the process of completing the sequencing. As a result, we are making too many inferences for the data to be completely accurate.
ReplyDeleteAs stated in both the article and in the summary, this amazing feat was only possible because the horse DNA was preserved in a permafrost. This is definitely a limitation for any prehistoric hominid DNA recovered. Even early humans could not survive in such frigid climates. Therefore, it would be highly difficult for any usable DNA to be uncovered. Well-preserved DNA will be low in abundance, making the work of scientists even more difficult. The fragmented DNA will give way to even more guesswork and inference.
Science and technology is advancing rapidly, causing us to transition rapidly into newer and newer methods. Older traditional methods will become obsolete as they lag behind in turnaround time and productivity. Newer and more productive methods will soon mask the efforts of traditional methods, making them unworthy and useless in the face of scientific research.
In order for us to fully understand the evolutionary process, we must take several things into consideration. It is not only the genetic factors, but also the epigenetic factors. We must keep in mind that there are social aspects in addition to genes. As we have explored in previous weeks, there is a lot more to the nature vs. nurture debate. One is no more important than the other. They both work hand in hand, hence the need to understand both the organisms' genomes and their social behaviors.
I think it is absolutely awesome that we can recover a horse that lived 700,000 years ago through DNA sequencing. I also found it fascinating that we are able to do this because of the discovery of the leg bone in permafrost which meant that the DNA was degraded slower. This is a great use of our sequencing technologies because it reveals connections of animals to ancestors from so many years ago. I think as our DNA sequencing techniques advance even more, sequencing will be the best method of looking at the evolution of organisms because it reveals so much information about an organism. I found it interesting that through this sequencing, scientists discovered that the Przewalsky horse came from a separate branch from the domestic horse which was thought to be before. Scientists will use this technology to compare other specimen’s and derive other common ancestors in the future. I am very excited to see what later research will reveal about wild life and their ancestors.
ReplyDeleteThis article just shows how powerful and lucky we are to have these modern technology available today. To be able to sequence the genome of a 700,000 year old horse with only a small amount DNA is just amazing. If we are able to accurately sequence these genomes, researchers could possibly genetically resurrect pre-historic animals back to life--just imagine a zoo that has displays live mammals from different time periods (physically observe evolution) although its probably not the best idea. But just having that ability is so mind blowing to me. Of course one of the biggest limitations in doing so, like many have mentioned above, is the amount of DNA available due to degradation. However, we have developed techniques such as PCR to amplify the amount of DNA left so there won't be a problem of having enough DNA once some DNA is discovered. I thought it was interesting how the researchers had to use multiple genomic sequences of the horse (of different species, of different time periods, and even subspecies of horses) to puzzle the 700,000 year old horse genome. Although this may pose some errors and perhaps 'bias' on the way we think horses a sequenced, I think its the best reference we have available. In the same manner, we can use the human genome to sequences our ancestors such as the homo erectus. I don't think that the traditional methods for mapping gene sequences will become obsolete. Perhaps we will improve on the methods but the concept of the traditional methods will still be relevant in the future. In the future, because of the available genomic sequences we have already discovered there will be some technology that integrates that information to make sequencing easier and a lot faster. But until then, genomics seem like such a open field for so many possibilities in learning the evolution of all living things!
ReplyDeleteIt was interesting to see the genome of a 700,000 year old horse being sequenced. The idea of doing something like this is pretty much mind blowing considering that the human genome was completely mapped only a few years ago. It is tough to be fully on board with the idea of using the DNA of other specimens as a reference to complete the sequencing because there could be some differences or uncertainties with the ancestor that cannot be explained through the reference specimens’ DNA. This can lead to many people questioning the validity of the genome. This does seem to be the best method at the present time to analyze and sequence the genome of the ancient specimen; however, we should really proceed with caution when analyzing the genome because of its limitations. We should definitely consider the limitations of age and preservation when it comes to prehistoric hominid DNA. As mentioned in the article, the DNA will rapidly degrade after the organism died. If the hominid is dated back to 700,000 years ago or later, we must definitely consider how preserved it is before further analysis. Other things like SNPs and mutations should also be considered in the genome analysis. Through time, some changes in the genome might have become more permanent which would then alter our genome in comparison to a prehistoric hominid. As I mentioned earlier, genomic sequencing seems to be a good way to analyze prehistoric DNA, and it could even help us to understand how evolution took place over time. However, it is still a relatively new practice that has its own limitations. I do not think that it can be the sole method to understanding ancestry and evolution any time soon. Complementary methods can only further solidify the evidence that genomic sequencing brings about, so I do not see the harm in combining different methods to fully understand our past.
ReplyDeleteThe use of phylogenetic inferences certainly has it's limitations due to the paradox of development. The existence of these limitations places further limits on the use of "relative" DNA, since it is likely to find little genetic variation in situations where species differ phenotypically (that's the paradox). The successful use of an assumed relatives' DNA is predicated on how the assumption of evolutionary kinship was made. If it was made solely on the existence of phenotypic similarities, there is obviously room for error. Further limitations may arise when we consider the possible existence of more closely related species that have yet to be discovered. These potential "missing links" could then skew the accuracy of previously made assumptions regarding kinship. Any completion in DNA sequencing made with samples from these erroneously assumed kin could then become irrelevant, causing the need for the mapping process to begin again at stage one. I'm not sure if the use of say, phylogenetic trees could ever become obsolete, but DNA mapping is certainly a more elegant method. I don't think genomic sequencing should be the sole method for determining evolutionary relationships between organisms, but I don't see why it couldn't.
ReplyDeleteVanessa Merta
ReplyDeleteThis article is extremely interesting and I think that it is fascinating that scientists today are able to sequence a genome that is 700,000 years old. In my opinion, most cases of scientific advancement are in someway useful and should not be ignored. This technique may not be flawless yet, but with more research and testing we can either perfect it, or come up with some better way to sequence the genomes of these extremely old organisms. Especially when it comes to something that can be as controversial as evolution, we need to make sure that our scientific techniques are near perfected. This technique raises some concerns, which is why we need to keep developing new ideas. One concern could be that though we think that a fossil is an ancestor of a present day animal, their genetic make up could be very different. Also, the genes that caused the animal to become extinct would not match up with the present day relative. These could bring up some issues with the technique, which is why we need to keep working to improve it.
I believe that the sequencing of the 700,000 year old genome greatly supports the theory of evolution and shows how species are still related but advanced from their ancestors. Whether they are actually more advanced, such a change in brain size, it still shows how animals are evolved to their environment. The limitations to be considered however is human error since the genome is not sequenced as a whole but has to be pieced together. It may be possible that parts of the genome are not in the right order. Older methods that take more time and have more room for error, I believe, will become obsolete if these newer methods become more efficient. Still, using a modern horse's genome as a reference just shows that the relation between ancestral horses and modern horses does exist and there is genetic proof of it. Denying evolution becomes harder as more information is being discovered. Even so, sequencing the genome will not be the sole form of determining evolution because fossil evidence among others is still an important impact on determining evolution.
ReplyDeleteIt is very interesting the study used a technique similar to what we used in class. It reminds me of the in class experiment where we compared genes to find the parent of the child. It makes sense that when using a similar technique in real life, a far wider variety of specimens needs to be used to compare genomes. A potential limitation for sequencing prehistoric DNA is that multiple samples that are similar will have to be used. In particular for hominid DNA, the challenge isn't identifying ancient hominids, but rather finding well-preserved genomes that can be sequenced. In the far future it is easy to imagine current traditional methods becoming obsolete. Genomics is a rapidly changing field, with huge strides in sequencing occurring. Genomic sequencing wouldn't suffice as a sole method, because a physical sample would need to be found first to obtain genomic information. A combination of a physical sample as well as a sequenced genome, would be sufficient to show evolution between different physical samples.
ReplyDeleteI find it very intriguing that dna has been preserved from a specimen over 500,000 years old. To me that is mind boggling that they not only have the dna but can fully sequence it. I think that since they had to compare this dna to various specimens and somewhat construct it, makes me question how valid the sequencing is. I'm sure that it is as accurate as possible but pulling and comparing to different types of specimens can't give them a true sequence either.
ReplyDeleteThis article reveals the fascinating uses of genetic technology beyond identifying and classifying certain genetic behavior. The ability to sequence the genome of a 700,000 year old horse was something even scientist didn't think was possible. However with this knowledge comes new possibilities, one of which that was mentioned in the article was the ability to resurrect extinct species by "copying and pasting" genes of extinct species into the existing genomes of living relatives. It is hard for me to imagine our world today with the resurrection of an extinct species like the mammoth for instance. The process of evolution and extinction is purposeful in many ways, resurrecting an extinct species that is not fit to live in today's environment is useless and unjust. There may be a few benefits in resurrecting extinct species and having the ability to augment the genome of living species, but I believe it could also be very detrimental.
ReplyDeleteThe thought that one day scientist could resurrect extinct species also raises many future ethical issues. How will scientist decide what species to resurrect from extinction? Although the context of this article is about sequencing the genome of a 700,000 year old horse, the same possibility of resurrection of extinct species also applies to ancestral human species. Will today's human's one day live among the Homo erectus species? Will these revived ancient human species have rights? Or will they be used strictly for research? The possibilities of genetic science are are limitless, but without careful thought and consideration, it could be easily taken advantage of.
Something like this seems so inconceivable to me, yet these incredible accomplishments are taking place every second. I would like to know how another specimen’s DNA is assumed to be related to another’s, what criteria do these researchers use to find which genomes are most closely related. Moreover, I find it intriguing as to how they put together this broken up DNA for thousands of years ago. What methods do they use to put these broken up DNA fragments together again? I think that older traditional methods will not become completely obsolete since they have produced such significant discoveries; although they will most likely be improved upon and tweaked. I do think that genomic sequencing is the primary method for determining how organisms evolve and are related because by comparing the genomes of different species, we learn more about what mutations could contribute to evolution for example.
ReplyDeleteGenomic sequencing just might become obsolete soon. Reading this article, we once again realize how much science is ever-changing/evolving. So it only makes sense that past technology will need to evolve as well. One crazy thing about this, however, is how drastically more precise learning about evolution can now be. Though DNA sequencing has it's faults, it's also one of the best ways to narrow down relationships between genes. One thing that scares me though is the fact that the DNA found will need something to be compared to. So once more, science has found another reason to continue storing people's genes.
ReplyDeleteGenomic sequencing just might become obsolete soon. Reading this article, we once again realize how much science is ever-changing/evolving. So it only makes sense that past technology will need to evolve as well. One crazy thing about this, however, is how drastically more precise learning about evolution can now be. Though DNA sequencing has it's faults, it's also one of the best ways to narrow down relationships between genes. One thing that scares me though is the fact that the DNA found will need something to be compared to. So once more, science has found another reason to continue storing people's genes.
ReplyDeleteGenomic sequencing just might become obsolete soon. Reading this article, we once again realize how much science is ever-changing/evolving. So it only makes sense that past technology will need to evolve as well. One crazy thing about this, however, is how drastically more precise learning about evolution can now be. Though DNA sequencing has it's faults, it's also one of the best ways to narrow down relationships between genes. One thing that scares me though is the fact that the DNA found will need something to be compared to. So once more, science has found another reason to continue storing people's genes.
ReplyDeleteI think that scientists should tread very carefully with using the DNA of another species that they believe to be related to the species in question as a reference in order to complete the older DNA sequencing. The assumption that the two species are related already place a margin of error in the so-called completed DNA sequence. If prehistoric hominid DNA be discovered frozen such as this prehistoric horse, then we should consider whether or not there is another prehistoric human ancestor that is closer in DNA to the human is found. Similar to the horse, using DNA of a present species could allow us to make mistakes in the genome of the older species. Mapping related organism could become obsolete if we map the DNA of every known current known species and freeze them to allow our descendents to connect the future organisms. However, I do not believe that the traditional method of mapping evolution will become obsolete. The traditional method has usually involved looking at similar parts and why these parts evolved due to an environmental change. Therefore genomic sequencing can not become the sole method.
ReplyDeletethe sequencing of the 700,000 year old genome greatly supports the theory of evolution and shows how species are still related but advanced from their ancestors . Finding the genetic sequence can provide a useful information, however I do not think it will replace other methods of determining organism evolution. The sequence can determine some things, but not determine the evolution of human beings.
ReplyDeleteI found this article to be extremely interesting. To begin, the fact that it is in a "popular mechanics" website shows just how relevant genomics and science is in many different fields...It is incredible that scientists can sequence a horse's genome from 700,000 years ago by comparing it to similar species and across different time periods. Due to the nature of the ice in Canada surrounding the fossil, the DNA was preserved over this long stretch of time. I wonder if it is possible for human fossils (though they may not be as old) to be sequenced if bones were found in the ice age period. This article shows promise for how science and genome sequencing could develop in the future.
ReplyDelete