shamon

What are the latest numbers on how related Bonobos is to humans? What about common chimpanzees? I'm looking for pointers to relatedness.

The Lone Ranger

I'm speaking off the top of my head here, but common chimpanzees and bonobos are descended from a common ancestor that lived after the split between the hominid and chimpanzee lineages. So, bonobos and common chimpanzees are equally closely-related to humans. (There's about a 1.6% genetic divergence between bonobos/chimpanzees and humans, if I recall correctly.)

You might check Jared Diamond's The Third Chimpanzee for confirmation. I read this a while ago, and it's quite good.

Cheers,

Michael

shamon

I’ve been having a haunting quandary lately related to Bonobos. Here’s a website with an estimate on relatedness: <a href="http://www.beyondveg.com/billings-t/comp-anat/comp-anat-2b.shtml" target="_blank">url</a>

Do most people scientists agree that the Bonobo is more genetically related to humans than chimpanzee? Is this an assumed fact nowadays? I just want to make sure there isn’t any ambiguity about this point.

SPECIES COMPARED
Genetic Distance (Delta)

Human / Chimpanzee 1.9

Human / Bonobo 1.8

Human / Gorilla 2.4

Human / Orangutan 3.6

[ April 05, 2002: Message edited by: shamon ]</p>

Peez

Bonobos and chimpanzees are members of the same genus (Pan), and so are more closely related to each other than to humans (genus Homo), and humans are equally related to each of them:

-------------Human: Homo sapiens
.\
...----------Bonobo: Pan paniscus
........\
..........---Chimpanzee: Pan troglodytes

This is just another way of saying what The Lone Ranger has already posted. According to <a href="http://www.gate.net/~rwms/primegendist.html" target="_blank">this site</a> chimps are slightly more genetically similar to humans (1.6% difference) than are bonobos (1.7% difference).

Peez

[ April 05, 2002: Message edited by: Peez ]</p>

The Lone Ranger

shamon:

Well, the cited study is almost 20 years old, so I wouldn't be entirely certain of its reliability. (Genetic techniques were in their infancy then, and not entirely reliable.) In any event, the difference between 1.8% and 1.9% is probably within the error limits of the study.

The studies I've seen strongly suggest that the common chimpanzee/bonobo split occurred after the hominid/chimp split, which would almost have to mean that common chimps and bonobos are equally closely-related to humans.

Even so, many people have claimed that the behavior of bonobos more closely resembles human behavior than does common chimpanzee behavior.

To me, at least, bonobos look more "human" than do common chimps. I remember flipping through an issue of Natural History a few years ago and glancing at a picture of a dark-skinned man reclining on the ground. Something seemed wrong somehow, so I turned back to the picture for a second look -- and realized that it was a bonobo, not a human.

***

So anyway, what's the bonobo-related quandary that you've been having?

Cheers,

Michael

Edited to add: Thanks, Peez.

[ April 05, 2002: Message edited by: The Lone Ranger ]</p>

Peez

"Relatedness" and genetic distance are not exactly the same thing, though they are "related" . Taxonomists usually think of "relatedness" as how far back up the evolutionary tree one must go to find a common ancestor. The common ancestor of the genus Pan and the genus Homo existed about 6 million years ago. This ancestral population was divided: one group eventually evolved into the most recent common ancestor of the chimps and bonobos (this population was then divided and evolved into chimps and bonobos), while the other group eventually evolved into humans.

Closely-related species tend to have very similar DNA, but species that have evolved adaptations to a new environment often have large differences in some of their coding DNA. Non-coding (or "junk") DNA is not affected by natural selection, and so is generally expected to be more similar in closely-related species than in distantly-related species (there are exceptions).

I hope that this helps.

Peez

Myrmecos

Shamon,

What is missing from your data table is the distance of bonobos to chimps. If it were included, I expect you'd find that chimps and bonobos are more closely related to each other than either are to humans.

Genetic distances can be quirky. While humans are 1.8 from bonobos and 1.9 from chimps, we cannot say from these two numbers alone how far chimps and bonobos are from each other. This is much like knowing that both Boston and Washington are 200 miles from New York- with these numbers we still cannot say how far Boston is from Washington.

shamon

I was just confused about how Bonobos could be more related, since it seems impossible. If they’re equally related then there’s no quandary. I must have mis-heard/read it somewhere.

Thanks for all the help!

Dr.GH

Another good article is:

<a href="http://www.pnas.org/cgi/content/full/96/18/10254#Top" target="_blank">http://www.pnas.org/cgi/content/full/96/18/10254#Top</a>

and

<a href="http://www.pnas.org/cgi/content/full/97/9/5003?ijkey=LnVk.LG5ZGDKk" target="_blank">http://www.pnas.org/cgi/content/full/97/9/5003?ijkey=LnVk.LG5ZGDKk</a>

You might need to register (free) to read the full text.

Peez

From the site that I linked to, chimps and bonobos differ by 0.9%.

Peez