MrDarwin

No time to discuss, but this stuff looks pretty interesting:

<a href="http://www.washingtonpost.com/wp-dyn/articles/A32877-2002Apr11.html" target="_blank">Study Compares Human, Chimp Brains</a>

[ April 11, 2002: Message edited by: MrDarwin ]</p>

MrDarwin

<a href="http://www.nih.gov/news/NIH-Record/04_18_2000/story02.htm" target="_blank">Another interesting article</a>

[ April 11, 2002: Message edited by: MrDarwin ]</p>

Dr Rick

Well, I don't know about the rest of you guys, but quite frankly, I'm floored: here all along I was so certain that MrDarwin's brain was pretty much no different from that of a chimp's...

Good article and links, btw; the first is a particularly good read for those that are inclined to assume that non-human primate brains and the behaviors that arise from them are predictive of human behaviors.

Rick

[ April 11, 2002: Message edited by: rbochnermd ]</p>

echidna

What does the first article mean by "genetic activity" ?

MrDarwin

Good question. I haven't had time to look into this, but as usual the second- and third-hand reporting for the popular press--probably based on a press release not written by the researchers themselves--leaves something to be desired.

ksagnostic

Thanks for the links, Darwin.

Here's another!

<a href="http://www.nsf.gov/sbe/nuggets/021/nugget.htm" target="_blank">http://www.nsf.gov/sbe/nuggets/021/nugget.htm</a>

And another!

<a href="http://www.sciencedaily.com/releases/2001/09/010905071926.htm" target="_blank">http://www.sciencedaily.com/releases/2001/09/010905071926.htm</a>

ksagnostic

One more link from Discover Magazine...

<a href="http://www.discover.com/may_02/gthere.html?article=featchimp.html" target="_blank">http://www.discover.com/may_02/gthere.html?article=featchimp.html</a>

MrDarwin

Here is the report on Science Daily, which usually has pretty good science reporting:

<a href="http://www.sciencedaily.com/releases/2002/04/020412080048.htm" target="_blank">Researchers Uncover Brain Patterns That Differentiate Humans From Chimpanzees
</a>

The Science Daily article also contains a link to the <a href="http://ucsdnews.ucsd.edu/newsrel/health/Gene%20Expression.htm" target="_blank">original press release</a>.

[ April 12, 2002: Message edited by: MrDarwin ]</p>

lpetrich

The "gene activity" measured was how much messenger RNA would stick to some other mRNA samples used as probes; this is a function of (1) how much is expressed and (2) how similar the sequences are.

The organ systems compared were the brain, the liver, and the blood, most likely white blood cells.

The liver and the blood turned out to be much the same for all the species examined, with differences approximately correlating with the amount of time since lineage separation (human and chimp closer to each other than either is to rhesus monkey).

However, there was a big difference with the brain; our species was much more different from the other species than those species are from each other.

Which suggests that our species has had a large amount of brain evolution behind it, brain evolution over the last 4 million years or thereabouts.

If such brain differences had not been found, someone quoted in a Science article on this subject mentioned that biologists would have to take up metaphysics, and fundamentalists would be dancing in the streets.

But they do exist, and they are remarkably big.

Amen-Moses

Which species were being compared.

i.e did they compare say Orangs with Chimps and find no differences or just different differences?

I would be very interested in knowing whther there is some specific common difference between social species and non social ones or whether different social species have evolved different solutions to give the same sort of adaptations.

Amen-Moses

[ April 13, 2002: Message edited by: Amen-Moses ]</p>