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?
I 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 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?
DeleteI 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.
I 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.
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.
In 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.
ReplyDeleteI 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.
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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 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.
It 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.
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.
This 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.
It 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.
ReplyDeleteThe 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.
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.
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.
It 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.
ReplyDeleteSomething 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.
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.
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