Humans Share a Common Ancestory with other Primates
I'm assuming the BoP is on you to affirm the resolution. Am I correct?
If not, we'll debate that too. ;)
The first piece of evidence that supports Humans share a common ancestor with other primates is mitochondrial DNA (mDNA). The mitochondria within our cells have an entirely different DNA sequence than the DNA that carries the genetic information for our development (nuclear DNA). Another unique factor of mDNA is it can only be inherited from the mother and not from the father. This allows for testing the mitochondrial genome of two individuals to see if they are related through maternal lines from a common ancestor. If they share mDNA they are of common descent. If they don't share mDNA they don't have common decent. When human mDNA is compared with other mammals we find a match. Our closest non-human relatives are Chimpanzees - followed by Gorillas and then Orangutans.
To test common ancestry on the fathers side we can look at the Y-chromosome as it, conversely, is only passed on by the father. When human Y-chromosomes are compared with other mammals we once again find a match. The Y-chromosome shows that our closest non-human relatives are once again Chimpanzees - followed by Gorillas and Orangutans.
A third piece of evidence that supports humans share a common ancestry with other primates are endogenous retrovirus'. A normal retrovirus' is a virus that attaches itself to a cell and rewrites a specific portion of the nuclear DNA of a cell. After the retrovirus completes this task every cell that comes from that initial cell will carry that rewritten section of DNA. If the retrovirus rewrites the DNA of a sperm cell or a woman's egg then it becomes an "endogenous" retrovirus - as that creature grows every single cell in its body will have that rewritten section encoded in its DNA. And every single one of its offspring will have that rewritten section in their DNA. And it turns out we share endogenous retrovirus with every species on our planet. But the animal with which humans share the most endogenous retrovirus' are the Chimpanzee - followed by Gorillas and then Orangutans.
The genetic evidence that humans share a common ancestor with other primates is overwhelming. We have parallel lines of evidence that are all pointing to the exact same conclusion: mDNA, Y-chromosomes and endogenous retrovirus' all show that Chimpanzees are our closest ancestor followed by Gorillas and then Orangutans. And while there is a great deal more evidence I could provide I think this is more than enough to get the discussion going along. I eagerly await your reply Con.
(All sources cited are peer reviewed scientific papers published in academic journals)
The Evolution of Mammalian Gene Families
Genomic Divergences between Humans and Other Hominoids
Comparative Nuclear and Mitochondrial Genome Diversity in Humans and Chimpanzees http://mbe.oxfordjournals.org...
Dynamics of DNA Methylation in Recent Human and Great Ape Evolution
Excellent! I'm glad we agree. The Burden of Proof is on Pro to show, beyond reasonable doubt, that humans do share a common ancestry with primates. This means that I do not have to provide contentions of my own, but merely must show that my opponent's are false.
Thus far, he has presented three arguments to support his case. I will now rebut each.
I'm afraid Pro's science is outdated by over 10 years. The once popular theory of mDNA showing us a common ancestor has, in fact, been long debunked.
That may be why his source is from 1996...
But what's wrong with this theory?
The validity of this assertion, is dependent upon a critically important assumption: that mtDNA is, in fact, derived exclusively from the mother. However, we now know that this assumption is wrong
Just as women thought they were getting their fair shake in science, the tables turned. As one study noted:
One year later, researchers made this startling admission:
In 2002, a study was conducted that concluded:
And now we know that these are more than small “fractional” amounts of mtDNA coming from fathers. The August 2002 issue of the New England Journal of Medicine contained the results of one study, which concluded:
Ninety percent! And all this time, evolutionists have been selectively shaping our family tree using what was alleged to be only maternal mtDNA! This recombination ability in mtDNA makes the entire discussion a moot point. As Strauss noted:
Science is fickle, ain't it?
Again, my opponent's science is out of date.
On Wednesday, January 13, 2010, Associated Press staff writer Seth Borenstein reported:
Looking closely at this study, one finds several glaring things that are amiss. Human evolution must be assumed in order for the study to make any sense. It must be assumed that humans evolved from lower mammals and that chimpanzees are our closest relatives. Assumptions make for bad science.
Furthermore, one of the reasons that supposedly shows humans and chimpanzees are closely related is their DNA resemblance... an idea which has also been refuted.
 Strauss, 286:2436, emp. added
 Morris and Mightowlers, 2000, 355:1290, emp. added
 Williams, 2002, 347:611, emp. added
 Schwartz and Vissing, 2002, 347:576, emp. added
 Strauss, 286:2436, emp. added
Thank you Con for your response. Though I was hoping to debate someone who would actually formulate arguements and not just cut and paste from a christian apologetics website. You could have saved us all the trouble by providing the link to http://www.apologeticspress.org...; instead of the charade of listing your supposed sources numbers 1-5.
I find it incredibly frustrating and tedious that the anthropologist "you" quoted, Henry Harpending, has no expertise and has conducted no research whatsoever in genetics. In fact, he hasn't published a single scientific paper on anything. He is not a scientist. He doesn't do scientific research. Why you would site him as an "expert" in the field of genetics is beyond me. Even worse, the quotes that you provided in no way impact the validity of mDNA being used to support common ancestory. The concern that Henry Harpending was addressing was that if mDNA was cross contaminated by the fathers genome we would not be able to determine an exact date for Mitochondrial Eve. He did not, nor did any of your other references, makes the claim that mDNA cannot be used to show common ancestry. You are trying to add things that none of your sources said.
You make the statement, "The validity of this assertion, is dependent upon a critically important assumption: that mtDNA is, in fact, derived exclusively from the mother." This is entirely false. Even if you could show that mDNA can be transferred via the father it would in no way impact the conclusion. mDNA would still be passed through paternal inheritance. It would still show that humans and apes share a common ancestry.
It's also a shame that you didn't bother to read the paper you cited by Schwartz and Vissing. In the case of the 28 year old man the paper states, "Sequencing of blood mtDNA from the patient's healthy parents and from his paternal uncle demonstrated that the haplotype of the patient's muscles mtDNA was identical to that of his father's and uncle's blood. The haplotype of the patient's blood was identical to that of his mother."
The man had chimeric mitochondrial myopathy. It is an incredibly rare disease. So rare, in fact, that there have only been 30 documented cases worldwide. And it is not clear which mDNA the man would pass along to his offspring. Either way, to try and debunk the maternity (paternity still withstanding) of mDNA by using a disease that affects only one in two-hundred-million people is completely absurd.
As for the mice, the scientest were able to trace fractions of the fathers mDNA by a specialized process. The mice mDNA was none the less still maternal.
I wasn't kidding when I said the research showing that mDNA proves common ancestory is lock solid. And it has only gotten better over time. Within recent years we have been able to completely map mitochondrial genomes from ten different ancient modern humans for which reliable radiocarbon dates are available. And this has given us the ability calculate the human mtDNA mutation rates directly. But don't take my word for it, here's a peer reviewed scientific paper (more recent per your request) from 2013 that you can read for youself:
Your assertion that,"The once popular theory of mDNA showing us a common ancestor has, in fact, been long debunked." Is completely false. Had you actually done the research for youself instead of just parroting Apologetics Press you might have known this line of attack would be a complete waste of time.
Mitochondrial DNA used to determine common ancestory stands. And debunking it would require more than just showing it isn't neccissarly passed through maternal lines. You would have to show that it isn't passed by either of the parents at all.
On to your next point about the Y chromosone. Your offer up a quote about how human and chimpanzee Y Chomozones differ by thirty percent. This is a red herring. It is not the percentage of shared genetic material that shows common ancestory. It's the shared genetic material occuring in the exact same sequences and in the exact same locations that shows common ancestory. For more on that check out this peer reviewed scientific paper:
You also claim that "only two chimp chromosomes have been examined in great detail." This statement is demonstrably and painfully false. Please, do your reasearch instead of just parroting wild assertions. I really don't know where you come up with this stuff. All 48 chimpansee chromosomes have been studied and poored over extensivley. There are litterally hundreds of peer reviewed articals that have been written on this. Here's just a couple for you:
Next you try to argue that ERV aren't the prodcut of retrovirus' because they serve a function. Firstly, this is a non-sequitor (it does not follow). Just because ERVs are functional does NOT mean that they aren't the product of retrovirus'. You're statement . . . "Viruses do not randomly insert tens of thousands ERVs in exactly the right location to provide us with invaluable function." . . . is exactly correct. Retrovirus' do not insert tens of thousands of ERVs at a time. They insert one at a time. And the vast majority of ERVs in our DNA are non-functional. They serve no purpose. Of the nearly 100,000 ERVs in our genome only 97 of them are active. Less than one in ten-thousand are being utilized by our DNA. And I'm really kind of surprised you made this arguement because the only peer reviewed artical that you did site clearly spells this out. But if you would like further reading on the number of ERVs and their functions here's another good one:
In closing, the evidence provided by mDNA, the Y chromosome, and endogenous retrovirus' all stand. If Con wishes to debunk them he is going to have to do far better than Apologetics Press.
My use of apologeticspress.org has been addressed in the comments.
It would be much appreciated if Pro would follow the layout I've provided for each of his points. It makes it more difficult to follow, otherwise.
Finally, I would like to state that I've now had time to do more research on the subject, and have decided to switch my approach to Pro's contentions.
With that said, let's get back to it!
I agree that all human mDNA can be traced to a common ancestor. The date of that ancestor's existence aside, it is overwhlemingly obvious that there is one common ancestor. But is that ancestor shared with primates? I would encourage Pro to show some hard evidence that would actually give us something to go on. Just because there are similarities between chimp and human mDNA does not mean that we share the ancestor with apes.
Another note: I would request that Pro actually cut out the paragrpahs/sentences from the material he is referring to (or at least source the information) after each claim, rather than making a lot of different statements and providing us with a few blue hyperlinks at the end.
Sadly, this will have to conclude my rebuttal on the first point, since I concede that matters such as the age of the ancestor (and thus paternal influence on mDNA, as well as Dr. Harpending's credibility) are moot.
Once again, I would encourage Pro to actually show the links between his arguments. What he originally said was, basically...
a) Y-Chromosome's are strictly paternally transferred
b) We match chimps pretty closely
c) We're related to chimps
Then in R2 he comes back by saying "It is not the percentage of shared genetic material that shows common ancestory. It's the shared genetic material occuring in the exact same sequences and in the exact same locations that shows common ancestory"
But again, how? And where is he getting this from? He offers up a paper shortly afterwards that supposedly verifies this... but the paper says nothing on this subject. At least, if it does, I'm certainly not seeing the connection. I would love for Pro to enlighten us on this, though.
Until then, there is no "proof" that Y-Chromosomes are evidence for us sharing an ancestor with primates. Since Pro has the BOP, he must prove this beyond doubt.
I will respond to what my opponent said first, then (since I definitely have space) I will talk about a few other flaws with using ERVs as "evidence" for human evolution from primates.
P3a. Random = No purpose
Let's address each of my opponent's major statements here.
I) "Just because ERVs are functional does NOT mean that they aren't the product of retrovirus'."
True enough. Of course this doesn't 100% prove my statement. But it is certainly unlikely that a viruses would randomly insert ERVs into us in the exact location needed for genome transcription. If these ERVs were an accident, then why would they be so vital to us?
II) "Of the nearly 100,000 ERVs in our genome only 97 of them are active."
.... Would you like to source that, Pro? You said that information came from my own paper... but the only thing I can think you might be referring to is the sentence, "114 of the ERV-derived transcription start sites can be demonstrated to drive transcription of 97 human genes..." But nowhere does it say that there are only 97 of them active...
So we see that ERVs are extremely unlikely to be planted randomly by viruses. But that's not the only thing suggesting ERVs are not evidence for evolution.
P3b. Similar ERVs in other organisms
If we came from apes, and apes descended from some other creature, and that creature from another... then it would make sense that all creatures would share some ERVs, with most ancient ones having the fewest, and their descendents having more as you progressively go down the evolutionary tree. However, this is not quite the case.
"We have sequenced and characterized an endogenous type D retrovirus, which we have named TvERV(D), from the genome of an Australian marsupial, the common brushtail possum (Trichosurus vulpecula). Intact TvERV(D) gag, pro, pol, and env open reading frames were detected in the possum genome. TvERV(D) was classified as a type D retrovirus, most closely related to those of Old World monkeys, New World monkeys, and mice, based on phylogenetic analyses and genetic organization."
"For instance gamma-retrovirus was isolated from trophoblastic cells of the baboon placenta. This virus was found to be very closely related antigenically and by sequence homology to the endogenous RD114 virus in cats (which is itself unrelated to endogenous FeLV). Benveniste and Todaro observed, like we did for jungle fowl, that only certain species of the cat genus, Felis, possessed this endogenous genome related to the baboon ERV. In contrast, all species of baboons carry this virus so it would appear to have been present in the germ line of primates much longer than in cats. Thus it seems evident that a horizontal, infectious event occurred to transfer the virus from baboons to cats, whereupon it became endogenous in the new species."
While it seems like, at first glance, the match between our ERVs and primates' might signify something... ultimately, it does not.
But finally, we have
Basically, apoptosis is your body's process for killing infected cells. If ERVs truly did come from viruses, and weren't planted with purpose, then your body would react in the same way that it does to any foreign infection. It would destroy the virus and all affected cells through apoptosis.
The very fact that there are so many ERVs in our system shows us that apoptosis is not occuring. Thus, these cells are not infected. These cells are performing how they were designed to function.
I look forward to Pro's response, and seeing if he can find linking evidence to support his first two points, as well as rebut my arguments on his third.
For now, the resolution is negated. Back to you, Pro.
mDNA proves humans and primates share a common ancestry:
"Based on the evidence from mtDNA sequences, chimpanzees and humans were determined to be each other's closest relatives. These studies further suggest that humans and chimpanzees separated almost five million years ago, and the human-chimp clade separated from gorillas almost eight million years ago . . . Subsequent analyses from even more genes have corroborated this conclusion reached by Ruvolo and the earlier mitochondrial DNA studies."
- Rediscoverying Biology: A Molecular and Global Perspective (2013) [Unit 9: Human Evolution]
I will also provide a link for the peer reviewed scientific paper that supports this conclusion as well: http://labs.eeb.utoronto.ca...
(The reason I haven't directly quoted from peer reviewed material is because, as anyone can see clicking on the link, they are highly technichal writings filled with graphs, charts, statistics, and complex modeling that does not have cookie cutter statements or catch phrases. That is why I instead paraphrase and provide a link that others can check for themselves. However, if you're more comfortable having a Biology textbook paraphrase, I am happy to provide the above quote.)
Concerning the Y Chromosome I showed proof of this in the Paper I cited in my opening arguments. This paper conclusively proves the link between humans, chimpanzees, and gorillas. I apologize once again as there is no cookie cutter statement so I will instead quote what the Paper said about our primate lineage in regards to the Y chromosome:
"As the molecular-clock hypothesis seems to hold well for the 53 intergenic regions and for the synonymous sites used in this study, these regions are suitable for estimating the divergence dates among the human, chimpanzee, and gorilla lineages. Our estimates are similar to those of Goodman et al. (1998) of 7 million and 6 million years ago for the gorilla branching node and the human-chimpanzee divergence, respectively. In any event, our data suggest that the internodal time span between the human-chimpanzee divergence and the gorilla speciation event is about one-third of the divergence time between the human and chimpanzee lineages."
Albeit a bit technical, it clearly spells out the common ancestory of humans and primates. Though, to really understand why that is the case, you'll have to read the paper yourself which I'll once again cite:http://www.ncbi.nlm.nih.gov...
Also there was some confusion on the paper I cited, "He offers up a paper shortly afterwards that supposedly verifies this... but the paper says nothing on this subject." I cited it in my second round as you had challenged (in the first round) that the Y Chromosome could not be used to determine common ancestry. The paper in question was on the methodology and legitimacy of using the Y Chromosome to determine lineage. It was not meant to address human/primate evolution. For that, see the link I posted above.
And now most painfully, on to ERVs.
"Of course this doesn't 100% prove my statement." No, it doesn't prove your statement at all. If you are going to assert that ERVs being functional mean they are not transmitted than you are going to have to show proof of that. All retrovirsus insert genetic material into their host cell through the process of reverse transcription. Re-coding your DNA is how they are able to replicate. That's also why they're the choice tool of molecular biologists when they want to re-write a section of DNA. ERVs are simply a retrovirus that infected a somatic cell of one of our ancestors.
"So we see that ERVs are extremely unlikely to be planted randomly by viruses." This statement could not be more untrue. They're not planted randomly. They are following a very specific genetic sequence determined by their RNA. It would be like saying humans "randomly" grow two arms and two fee. It's a complete misrepresentation of how the genome works. There's nothing random about the transcription.
I sure would -
Here's another paper that states it a little more succinctly -
And now here's where it gets tedious. First you you talk about TvERV(D) which is entirely consistent with the evolutionary model. Than you pivot to Cats and Baboons sharing what appears to be a somewhat similar ERV. However, the sience cited in this paper is from the 1970s. A lot has been learned about these two ERVs over the years and we now know they are not the same. Here's a much more up to date Paper on the topic:
"Phylogenetic analysis of FcEV and RD-114 fragments amplified from cat species and comparison with baboon endogenous virus (BaEV) fragments from monkeys suggested that RD-114 does not represent the cat strain of BaEV but is actually a new recombinant between FcEV type C genes and the env gene of BaEV."
Also, it's not just that we carry the same retrogenes as other primates. It's that the ERV's are in the exact same chromosomal locations which allow us to determine common ancestry.
In closing, imagine a tree for which there was a placard before it which stated “This tree was planted in 1901.” And then when you counted its tree rings it dated back to the year 1901. And finally, when you sent a sample off to the lab for radiometric dating the results came back for the year 1901. A person could argue that one of the dating methods was wrong. They might even be able to argue that all three dating methods were wrong. However, what would be impossible to argue is that all three dating methods were wrong and they all got the exact same date.
The same goes for the genetic evidence that humans and primates share a common ancestry. mDNA proves it. The Y Chromosome proves it. ERVs prove it. And they all agree upon which apes are most closely related to us. Con has tried their hardest to try and poke holes in the science. But the science is solid. And all three forms of evidence are converging on the same answer - our closest mammalian cousins are the Chimpanzee - followed by the Gorilla and then the Orangutan. Our common ancestry is not just swinging in the trees around us it is also inscribed deep inside our DNA. It is a heritage that is written in the languege of life and encoded in every single cell of our body. Our fellow primates are the great grand children of our great grand fathers.
JustinAMoffatt forfeited this round.
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