Human, Orangutans and Chimps

FireGarden

Philosopher
FireGarden
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Which is our closest relative? (Of the three, it's Humans. I know that! :) Which of the other two!)

John Grehan thinks that the physical similarities with Orangutans implies they are our closest relative. In spite of the genetic evidence.

Buffalo Museum of Science:
http://www.sciencebuff.org/humans_and_orangutan.php

Humans have a larger number of features that are uniquely shared with orangutans than with any other living ape. Schwartz (1984) proposed that humans are more closely related to orangutans than to chimpanzees - a model that contradicts the greater genetic similarity of base pair sequences in humans and chimpanzees.
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From the "mona lisa smile" pdf on that page:

The science of human evolution is confronted with the popular chimpanzee theory and the earlier but largely ignored orangutan theory. The quality and scope of published documentation and verification of morphological features suggests there is very little in morphology to support a unique common ancestor for humans and chimpanzees. A close relationship between humans and African apes is currently supported by only eight unproblematic characters. The orangutan relationship is supported by about 28 well-supported characters, and it is also corroborated by the presence of orangutan-related features in early hominids. The uniquely shared morphology of humans and orangutans raises doubts about the almost universal belief that DNA sequence similarities necessarily demonstrate a closer evolutionary relationship between humans and chimpanzees. A new evolutionary reconstruction is proposed for the soft tissue anatomy, physiology, and behavioral biology of the first hominids that includes concealed ovulation, male beard and mustache, prolonged mating, extended pair-bonding, “house” construction, mechanical “genius,” and artistic expression.
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The sci-buff website also includes some quotes of scientists on the matter:
http://www.sciencebuff.org/orangutan_points_of_view.php

Including:

Colin Groves. Australian National University

"Accepted ideas do need to be challenged,and if the challengers sometimes go rather over the top and find themselves in the realms of science fiction, well, at least they had made the challenge. As for Jeff Schwartz, may the Force be with him." (Journal of Human Evolution, 1987)



Maryann Ruvolo, Harvard University

Scientists should realize that this is a golden opportunity to get at some of the more interesting aspects of evolution. When molecules and morphology don't agree, that usually means some interesting convergence has occurred - and this is a good opportunity for studying selection and adaptation”. (Direct communication, 2003)



David Pilbeam. Harvard University

“Nothing about genetic data is now pre-selected, and there are several different approaches, phenetic as well as cladistic, using many many genes, which give a consistent answer. There are many people, much smarter than I am, who have addressed all of these issues long since. As far as I'm concerned, the issue is closed." (Direct communication, 2003)
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Not being an expert, I have to go with the majority of expert opinion and vote for chimps. Anybody want to make a case for orangutans?
 
From very quick reading, it seems to be one or two zoologists still clinging to an older theory in spite of the strong genetic chimp evidence. They think that the stronger morphological similarities between humans and orangutans are more important evolutionary evidence than the genetic studies. I am more inclined to go along with the view that it is more likely a case of convergent evolution. The overwhelming majority of zoologists think the evidence favours chimps, and as they are more expert than me I will take their word for it unless some stronger evidence comes up that changes things.
 
In terms of DNA, I believe the most parsimonious model is something like

[Common chimp]---[Pygmy chimp (bonobo)]---[Humans]-------[Gorilla]----------[Orangutan]

Interestingly, not only are chimpanzees our closest relatives, but we are theirs, and it seems they split off from our direct line long after the human line split from the gorilla line.

All the great apes (and I don't exclude humans from that description) are usually placed in familiy Hominidae. Orangs are usually placed in subfamily Ponginae, and humand, gorillas and chimps in Homininae.

(Interestingly, I understand it's now common to place both humans and chimps in the same biological tribe, Hominini. We aren't so much related to chimps as much as we are chimps).

I like orangs, but the majority scientific view is that they are our most distant relative among the great apes.
 
Professor Yaffle said:
From very quick reading, it seems to be one or two zoologists still clinging to an older theory in spite of the strong genetic chimp evidence. They think that the stronger morphological similarities between humans and orangutans are more important evolutionary evidence than the genetic studies. I am more inclined to go along with the view that it is more likely a case of convergent evolution.
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That's my take on the subject as well. Between DNA and morphology, I'd go with the DNA. From my rather superficial reading on the subject I gather that orangutangs (or Homo Pongo as I like to think of them) "walk" up in the trees, which makes me suspect that our common ancestor with the chimps and gorillas actually lost that ability - or ceased to express it - and humans have regained it for more earthbound purposes. Thoroughly speculative, of course :) .
 
The DNA is conclusive--chimps are our closest relative--You can see side by side chromosome comparisons...plus, chimps, gorillas, and humans all have the same non-working mutation of a gene that makes vitamin C in other mammals including orangutans...so it happened after the split...

http://www.indiana.edu/~ensiweb/lessons/c.fus.les.html
http://www.iidb.org/vbb/showthread.php?p=3243051
http://www.talkorigins.org/faqs/comdesc/images/retrovirus.gif

Even meercats stand upright sometimes... but the videos of the orangutans walking upright are pretty cool. But upright primates have de riguer for some time -- the rest just didn't survive as well as we did: http://www.nytimes.com/2007/06/26/science/26ance.html?_r=2&pagewanted=2&oref=slogin

These links shows us though that the orangutans are suggestive that our ancestors first stood up in trees rather than on the ground--

http://www.sciencedaily.com/releases/2007/05/070531150326.htm
http://www.geneticarchaeology.com/Research/Human_Ancestors_Learnt_to_Walk_Upright_in_the_Trees.asp
 
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I think this article explains it pretty well.

300px-Hominoid_taxonomy_7.png
 
Puppycow said:
I think this article explains it pretty well.

[qimg]http://upload.wikimedia.org/wikipedia/commons/thumb/1/1c/Hominoid_taxonomy_7.png/300px-Hominoid_taxonomy_7.png[/qimg]
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That was good. This is good too. http://news.nationalgeographic.com/news/2003/05/0520_030520_chimpanzees.html

Chimps and Bonobos are equally related to us, but some think we are closer to the Bonobo in major features. Both have been known to walk upright, but the Bonobo does moreso. http://www.sheppardsoftware.com/content/animals/animals/mammals/chimpanzee_primate.htm
http://www.awionline.org/pubs/quarterly/Spring02/bonobo.htm
 

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I recall a New Scientist article recently saying that bipedalism could have evolved for an arboreal lifestyle, and Chimps lost it in knucklewalking.

ETA:

I strongly recommend Frans der Waaal's books on this
 
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The following article puts a bit of a chink into the generally accepted primate phylogenic tree. Evidence of an LTR with retroviral insertions in African Great Apes, yet absent in Humans and Orangutans, is provided showing that Orangutan and Human may be more closely related than Human and Chimpanzee. Several speculations are proposed as to why this contradictory evidence appears -- Including the possibility that some/all of us monkeys may have interbred, as recently as 2-3 million years ago.

Source: http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pubmed&pubmedid=15737067
 
kjkent1 said:
The following article puts a bit of a chink into the generally accepted primate phylogenic tree. Evidence of an LTR with retroviral insertions in African Great Apes, yet absent in Humans and Orangutans, is provided showing that Orangutan and Human may be more closely related than Human and Chimpanzee. Several speculations are proposed as to why this contradictory evidence appears -- Including the possibility that some/all of us monkeys may have interbred, as recently as 2-3 million years ago.

Source: http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pubmed&pubmedid=15737067
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Though a primate orgy sounds fun... I think there are more likely explanations iin the article which was published in 2005:

The gorilla and chimp show separate infections of the retrovirus and it occurred after humans split (though I know there has been recent evidence of pre-humans and pre chimps continuing to tryst for quite some time)--so humans could have been immune and orangutans not exposed... and they propose a couple of other explanations...do you have any more recent info. on this? Orangutans are pretty damn smart, and I wouldn't mind having them a little closer on our family tree. :)
 
articulett said:
Though a primate orgy sounds fun... I think there are more likely explanations iin the article which was published in 2005:

The gorilla and chimp show separate infections of the retrovirus and it occurred after humans split (though I know there has been recent evidence of pre-humans and pre chimps continuing to tryst for quite some time)--so humans could have been immune and orangutans not exposed... and they propose a couple of other explanations...do you have any more recent info. on this? Orangutans are pretty damn smart, and I wouldn't mind having them a little closer on our family tree. :)
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Nope. As far as I'm aware, that article is the only one with an anomalous result. It's definitely intriguing -- if I were a creationist, I would be screaming that it proves retroviral insertions are unreliable for determining evolutionary lineage.

So, don't tell Kleinman.
 
kjkent1 said:
Nope. As far as I'm aware, that article is the only one with an anomalous result. It's definitely intriguing -- if I were a creationist, I would be screaming that it proves retroviral insertions are unreliable for determining evolutionary lineage.

So, don't tell Kleinman.
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I will keep it on the down low...I notice that they tend to stick to a single thread or two... so I think we're safe. I'd hate to have paul plugging in more math for making retroviral insertions de novo. :)
 
kjkent1 said:
Nope. As far as I'm aware, that article is the only one with an anomalous result. It's definitely intriguing -- if I were a creationist, I would be screaming that it proves retroviral insertions are unreliable for determining evolutionary lineage.

So, don't tell Kleinman.
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I'm pretty sure as more genomes are sequenced we're going to find more anomlous insertions like this and the question then becomes do we change the language used to describe the event (from astronomically unlikely to highly unlikely) or toss out ERVs all together. As I see it, the anomolies should warrent more study rather that cast doubt on the usefulness of ERVs in establishing common ancestry because they've just proven to valuable in constructing phylogenies consistent (or mostly consistent) with other methods.

Regards the OP, I think human chromosome 2 is a slam dunk on Homo and Pan sharing an MRCA. The ability to match up the telomeres and centomeres is just too unlikely to have any other explanation. All the other molecular evidence is "nothing but net" jump shots and the fossils are nicely executed layups.
 
UnrepentantSinner said:
I'm pretty sure as more genomes are sequenced we're going to find more anomlous insertions like this and the question then becomes do we change the language used to describe the event (from astronomically unlikely to highly unlikely) or toss out ERVs all together. As I see it, the anomolies should warrent more study rather that cast doubt on the usefulness of ERVs in establishing common ancestry because they've just proven to valuable in constructing phylogenies consistent (or mostly consistent) with other methods.

Regards the OP, I think human chromosome 2 is a slam dunk on Homo and Pan sharing an MRCA. The ability to match up the telomeres and centomeres is just too unlikely to have any other explanation. All the other molecular evidence is "nothing but net" jump shots and the fossils are nicely executed layups.
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Yes...I think it was kind of humbling to see chimps were more closely related to humans than they were to gorillas. Molecular DNA is revealing some really cool things. I often think about if Darwin could have seen a chromosome --especially chromosome 2. I think it's amazing how much we have figured out. ERVs ARE interesting...not just for ancestry...because it suggests a couple of other interesting things (e.g.bottlenecks and differences is ape population sizesas mentioned ) in the article and give us a clue for further study. Sometimes I think about how great it would be if Kleinman would use his brain to learn this cool stuff instead of frittering away his sanity proving that it just can't be so. We just found a million year old human molar yesterday and created synthetic bacteria...we got T rex collagen imprints recently that show that chickens are their descendants. This is really heady stuff--and some people still think that the earth was created 6000 years ago when god poofed two white people into a garden with a talking snake.
 
FireGarden said:
Which is our closest relative? (Of the three, it's Humans. I know that! :) Which of the other two!)

John Grehan thinks that the physical similarities with Orangutans implies they are our closest relative. In spite of the genetic evidence.

Buffalo Museum of Science:
http://www.sciencebuff.org/humans_and_orangutan.php



From the "mona lisa smile" pdf on that page:



The sci-buff website also includes some quotes of scientists on the matter:
http://www.sciencebuff.org/orangutan_points_of_view.php

Including:



Not being an expert, I have to go with the majority of expert opinion and vote for chimps. Anybody want to make a case for orangutans?
Click to expand...


Considering that chimps have free cycling esterus and orangs do not, chimps.
 
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