The Humans and Chimpanzees PP article.

[Mentat]

The "Humans and Chimpanzees" PP article.

I just now noticed that there's no "Physicspost.com Articles" Forum here anymore, so I don't know if there's been any discussion on this article, but I've got a couple of questions:

1) How different is the DNA of a chimp, when compared to another ape - like a gorilla?

2) If we are only 95% identical (genetically) to chimps, does that raise any dispute on whether there was a common ancestor, or on how long ago the divergance from that common ancestor occurred?

Any response is appreciated.

BTW, this was a very good article, and I highly recommend it.

 

[Greg Bernhardt]

Here is the article btw: http://physicspost.com/articles.php?articleId=31

 

[Monique]

A quick remark (I can comment more later) researchers at Wayne State University School of Medicine did genomic analysis of genes and came to the conclusion that chimps belong to the genus Homo.

http://news.nationalgeographic.com/news/2003/05/0520_030520_chimpanzees.html

Current naming:
Chimp - Pan troglodytes
Human - Homo sapiens

Suggested change:
Chimp - Homo troglodytes

That was about 6 months ago when the article got published in PNAS, I am not sure how the scientific community has digested the news though..

 

[Monique]

Here is the PNAS article, it requires a subscription though (which all academic institutions should have)

Implications of natural selection in shaping 99.4% nonsynonymous DNA identity between humans and chimpanzees: Enlarging genus Homo

 

[Phobos]

Originally posted by Monique
Current naming:
Chimp - Pan troglodytes
Human - Homo sapiens

Suggested change:
Chimp - Homo troglodytes

Here's the archived topic about it...
https://www.physicsforums.com/showthread.php?s=&threadid=2288&highlight=chimp

I'm still wondering whether "Australopithecus troglodytes" is more appropriate.

 

[Monique]

Originally posted by Mentat
I just now noticed that there's no "Physicspost.com Articles" Forum here anymore, so I don't know if there's been any discussion on this article, but I've got a couple of questions:

1) How different is the DNA of a chimp, when compared to another ape - like a gorilla?

I am actually not sure..

2) If we are only 95% identical (genetically) to chimps, does that raise any dispute on whether there was a common ancestor, or on how long ago the divergance from that common ancestor occurred?

Why would that cause a dispute whether there was a common ancestor?? The 95% identity, is probably based on the entire genomic sequences. In the recent article, researchers looked at genes and found that our identity is much higher: the functional important genes show 99.4% identity, while the not so important ones show 98.4% identity.

Here is the abstract of the article:

What do functionally important DNA sites, those scrutinized and shaped by natural selection, tell us about the place of humans in evolution? Here we compare approximately 90 kb of coding DNA nucleotide sequence from 97 human genes to their sequenced chimpanzee counterparts and to available sequenced gorilla, orangutan, and Old World monkey counterparts, and, on a more limited basis, to mouse. The nonsynonymous changes (functionally important), like synonymous changes (functionally much less important), show chimpanzees and humans to be most closely related, sharing 99.4% identity at nonsynonymous sites and 98.4% at synonymous sites. On a time scale, the coding DNA divergencies separate the human-chimpanzee clade from the gorilla clade at between 6 and 7 million years ago and place the most recent common ancestor of humans and chimpanzees at between 5 and 6 million years ago. The evolutionary rate of coding DNA in the catarrhine clade (Old World monkey and ape, including human) is much slower than in the lineage to mouse. Among the genes examined, 30 show evidence of positive selection during descent of catarrhines. Nonsynonymous substitutions by themselves, in this subset of positively selected genes, group humans and chimpanzees closest to each other and have chimpanzees diverge about as much from the common human-chimpanzee ancestor as humans do. This functional DNA evidence supports two previously offered taxonomic proposals: family Hominidae should include all extant apes; and genus Homo should include three extant species and two subgenera, Homo (Homo) sapiens (humankind), Homo (Pan) troglodytes (common chimpanzee), and Homo (Pan) paniscus (bonobo chimpanzee).

 

[Mentat]

Originally posted by Monique
I am actually not sure..

Where might one find such information?

Why would that cause a dispute whether there was a common ancestor??

Well, at least on how far back in the lineage the common ancestor was...since the divergance would be greater.

The 95% identity, is probably based on the entire genomic sequences. In the recent article, researchers looked at genes and found that our identity is much higher: the functional important genes show 99.4% identity, while the not so important ones show 98.4% identity.

Wow!

 

[Mentat]

Originally posted by Phobos
I'm still wondering whether "Australopithecus troglodytes" is more appropriate.

Why's that? Did we also descend from australopithecus (this subject's obviously not my forte )?

 

[Monique]

Originally posted by Mentat
Where might one find such information?

Well, go to PubMed, that is where all biotech related articles get indexed into a searchable database:

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed

NCBI is the National Center for Biotechnology Information
NLM is the National Library of Medicine

I don't think the gorilla genome has been sequences, do you'd have to rely on different genomic techniques to compare the identity between the chimp and the gorilla..

 

[Monique]

Here is a summary of the genomes that are being sequenced:

http://www.ncbi.nlm.nih.gov/genomes/static/EG_T.html