Did humans descend from other primates?

[McCulloch]

Man did not descend from the primates.

Did humans descend from other primates?
Are humans primates or should there be special biological taxonomy for humanity?
Please cite evidence.

[Goat]

g.

Also, as far as I know, no evolutionist claims that there is a direct lineage from a chimp to a human. So, even if there are similarities, a chimpanzee would not show how humans evolved from primates.

Sure it does. Specific genetic similarities determine relationships. This is done all the time, especially in the areas of paternity tests. The only difference is, in systematics we take it a few steps further.

Also, given the fact that we do not know what organism is the shared common ancestor of chimps and humans, there is no link established between chimps and humans. Yes, there are morphological and genetic similarities, but that in itself does not establish lineage. It can also be a result of a common designer.

Well, let's see here.

For common ancestry we have a large amount of data, an interpretation of the data, and a way to falsify the interpretation. We have predictions, and we have something that actually explains the data.

You have 'you don't know everything', so you want to throw out the evidence we DO have... There is no reason to say that does not show common lineage, and every reason to.

The problem with trying to invoke 'It can be the result of a common designer' is that there is no way to test for that, and it has no explanatory power other than "maybe god did it'. That is argument from personal belief, rather than looking at the data. No matter what data there is, you could say 'Maybe it's the result of a common designer'.. and no one could prove or disprove that argument. An argument that can be applied to any situation explains no situation, and is therefore meaningless.

[GrumpyMrGruff]

And onward to the original post:

Did humans descend from other primates?

This seems to be the most parsimonious explanation accounting for the pattern of chromosomal similarities in the great apes[1], the species distribution of shared ERVs (already mentioned)[2], phylogenies by genomic sequence comparison[3], and bio-geography (agreement of phylogeny with current/fossil primates' geographic distributions)[4]

Are humans primates or should there be special biological taxonomy for humanity?

It has already been pointed out that this is true by definition. However, the above evidences suggest we should go one step further: Yes, humans are primates and yes, all primates are related. No, there doesn't appear to be a need for a special taxonomy for humans (at least not until we go all transhuman and start genetically engineering ourselves ).

Please cite evidence.

A few representative reviews:

[1] The origin of man: a chromosomal pictorial legacy. Science (1982) 215(4539):1525-30.
[2] Distribution of human endogenous retrovirus HERV-K genomes in humans and different primates. Hum Genet (1995) 96:188-192.
[3] A Composite Estimate of Primate Phylogeny. Phil. Trans. R. Soc. Lond. B (1995) 348(1326):405-21.
[4] Primate evolution - in and out of Africa. Curr Biol. (1998) 8(16):R582-8.

[otseng]

I've given several examples of functions for ERV. So, how can a virus infect a reproductive cell, mutate to become inactive, yet also mutate to have a beneficial function in the host organism? ERV are supposed to be at best functionless, not impart a beneficial function.

Argument to incredulity?

ERV has historically been labelled as "junk DNA" and assumed to have no purpose.

Endogenous retroviruses provide yet another example of molecular sequence evidence for universal common descent. Endogenous retroviruses are molecular remnants of a past parasitic viral infection. Occasionally, copies of a retrovirus genome are found in its host's genome, and these retroviral gene copies are called endogenous retroviral sequences. Retroviruses (like the AIDS virus or HTLV1, which causes a form of leukemia) make a DNA copy of their own viral genome and insert it into their host's genome. If this happens to a germ line cell (i.e. the sperm or egg cells) the retroviral DNA will be inherited by descendants of the host. Again, this process is rare and fairly random, so finding retrogenes in identical chromosomal positions of two different species indicates common ancestry.

http://www.talkorigins.org/faqs/comdesc ... troviruses

These endogenous retroviruses (ERVs), contrasted with exogenous ones, now make up 5-8% of the human genome.[3] Most insertions have no known function and are often referred to as "junk DNA".

http://en.wikipedia.org/wiki/Retrovirus

And let me add that assuming ERV has no purpose has actually slowed down scientific progress.

Junk DNA, a term that was introduced in 1972 by Susumu Ohno,[25] was a provisional label for the portions of a genome sequence for which no discernible function had been identified. According to a 1980 review in Nature by Leslie Orgel and Francis Crick, junk DNA has "little specificity and conveys little or no selective advantage to the organism".[26] The term is currently, however, a somewhat outdated concept, being used mainly in popular science and in a colloquial way in scientific publications, and may have slowed research into the biological functions of noncoding DNA.

http://en.wikipedia.org/wiki/Junk_DNA

Now that recent research has shown that ERV can have a function, it falsifies the original assumption that ERV is junk DNA.

I would agree that if ERV is functionless, it would be better explained by some random process of virus DNA/RNA insertion than design. However, since science is now revealing that ERV have function, it is better explained by design.

[otseng]

WHy are you misrepresenting what is said? What has been said is that Chimps and humans share a common ancestor.. and therefore are 'cousin' species. Trying to say that anybody is saying any differently is a straw man.

I'm not saying that anybody here is claiming that chimps are the forefathers of humans. What I am questioning is the relevance of chimps. If chimps are not in the line of human evolution, then how do chimps show how humans evolved? What would be relevant is evidence of species that are in the direct lineage of humans.

The fact is that nobody knows what is the common ancestor between chimps and humans. Why cannot this evidence be produced? If no evidence can be produced, then it would be a baseless assertion that such an ancestor actually existed. And since this evidence cannot be produced, would producing a species not in the lineage of humans establish how humans evolved?

As for ERV's and chimps, that information is discussed here.
http://www.talkorigins.org/faqs/comdesc/section4.html

I would ask to not simply just provide a link to a webpage. Provide the relevant points and then only use links to show your source.

It isn't. It is just that there are vastly MORE similarities between humans and chimps than any other species. And, it isn't just one or two different ERV's, inserted in the exact same place, with the exact same gene sequence.. which, while unlikely is possible. It is many of them. There are ERV's that Chimps and humans share, and then there are ERV's that all the Great apes share. The number of shared retroviruses just so happens to correspond to the closeness on the family tree we are in.

If ERV are indeed functionless, I can see your point. However, recent studies show that ERV have function.

No, it doesn't mean that at all. Why are erv's not support to be functionless. On rare occasions, it might provide a function that gets incorporated later.. or if it is detrimental, it gets filtered out via natural selection. Just like any mutation.

It is only by recent research that ERV are found to have function. Prior to these findings, it was assumed that ERV have no beneficial function as stated by McCulloch - "Eventually, retroviruses are rendered inactive because of these mutations, and they sit quietly in the genome, a testament to an infection that occurred generations in the past."

[otseng]

"What was the common ancestor?"

We don't yet know with any certainty exactly where the split occurred, the oldest hominid, upright-walking(and thus in the same line or sidebranch of the line that led to modern humans)is Orrorin Tugenensis

So, no evidence exists of the common ancestor between chimps and humans.

"And what is the lineage between that ancestor and humans?"

Again, we don't yet know with any certainty

Out of all the species studied for evolution, you would think human evolution would be most studied area. However, we still do not know the lineage prior to humans.

"And how did the genetic swapping occur between the chimp line and humans?"

Like horses and Donkeys used to be able to do. They can no longer produce non-sterile offspring, but that is a recent development. The process of two species splitting would happen over time, not overnight.

What evidence do you have to show that chimps and humans can produce/have produced fertile offsprings?

It is either fact or everything is illusion meant to fool us.

False dichotomy. It is not either human evolution is true or everything is an illusion to fool us.

[nygreenguy]

ERV has historically been labelled as "junk DNA" and assumed to have no purpose.

Irrelevant. The world was once labeled as flat, new evidence has shown that to not be the case. Do you wish to throw that evidence out?

Now that recent research has shown that ERV can have a function, it falsifies the original assumption that ERV is junk DNA.

So what? This statement is irrelevant to the discussion.

I would agree that if ERV is functionless, it would be better explained by some random process of virus DNA/RNA insertion than design. However, since science is now revealing that ERV have function, it is better explained by design.

A gene gaining function after being functionless is not some wacky new novel phenomena. We see it all the time in genetics. It is only if you are naive to the science does this sort of stuff seem incredulous.

[otseng]

Also, if ERV are caused by a virus insertion, why should similarities be limited to the chimp? Shouldn't there also be ERV similarities between humans and other species in the human lineage?

Yes. And according to evolutionary theory, the further back the most recent common ancestor is the fewer ERV similarities there will be.

So, there should exist mutated ERV in humans that were originally injected in a distant lineage species?

If you find an ERV common to, for example, Gorillas and Humans but not present in Chimpanzees, you will have falsified the evolutionary model we have for primates.

How about if I find an ERV common to primates (including chimps), but not found in humans? Would it falsify the theory that humans came from primates?

There are two possible explanations:

1. Common ancestry
2. A creative secretive hidden God who wished to deceive humans into believing that there was a common ancestry.

Again, false dichotomy.

ERVs which do mutate, can become benign.

Yes, this is the basic theory behind ERVs. However, ERVs are not found to just be benign, but to have function.

And, yes, the greater the distance to the infected ancestor, the greater amount of mutations in the ERV.

Then a prediction from this would be that most (if not all) ERV should be functionless. Think of all the ancestor species prior to humans that could've been infected by a virus. This would span a period on the order of hundreds of millions of years. Many ERV injections could have taken place in the human lineage during this timeframe. And these ERV would have mutated since then.

A great number of research papers, done by qualified biologists confirm this point of view.

It is not so surprising that evolutionists would confirm their own point of view.

[otseng]

Similarities do not necessarily mean lineage. It could also mean they were designed is a similar fashion. HP and Gateway computers share many similarities, but they did not derive from the other.

No, but their designs were not done in a vacuum. In fact, they share a common ancestor, the minicomputer and the IBM PC. The commonality of their design can be traced to these ancestors and by cross-fertilization of the ideas of the design engineers.

Yes, they can be traced back to the ideas of the design engineers.

[otseng]

Yes. And according to evolutionary theory, the further back the most recent common ancestor is the fewer ERV similarities there will be. The data so far matches exactly with this prediction. If you find an ERV common to, for example, Gorillas and Humans but not present in Chimpanzees, you will have falsified the evolutionary model we have for primates.

Really? A HERV-K provirus in chimpanzees, bonobos and gorillas, but not humans. Curr Biol. 2001 May 15;11(10):779-83.

You stole my thunder.

However, the authors point out that this is consistent with the current understanding of primate phylogeny.

It's only a problem if one assumes quick fixation for the ERV - that it's inherited by every member of the population before speciation. In this case, the authors propose that some members of the ancestral species carried the inert ERV (and some didn't). It was only after the species diverged that genetic drift fixed the ERV in some species and led to its loss in our species.

What this demonstrates is that evolution is unfalsifiable. It can take in any evidence and present an ad hoc explanation for it.

[Goat]

WHy are you misrepresenting what is said? What has been said is that Chimps and humans share a common ancestor.. and therefore are 'cousin' species. Trying to say that anybody is saying any differently is a straw man.

I'm not saying that anybody here is claiming that chimps are the forefathers of humans. What I am questioning is the relevance of chimps. If chimps are not in the line of human evolution, then how do chimps show how humans evolved? What would be relevant is evidence of species that are in the direct lineage of humans.

The fact is that nobody knows what is the common ancestor between chimps and humans. Why cannot this evidence be produced? If no evidence can be produced, then it would be a baseless assertion that such an ancestor actually existed. And since this evidence cannot be produced, would producing a species not in the lineage of humans establish how humans evolved?

Because of the similarities in DNA, including ERV's, ti shows they have both evolved from a common ancestor, and the similarities between them show a 'clock' from when the two lines diverged.