Fw: Chimp and human

[Anders Gorm Pedersen]

"Michael L. Sullivan" wrote:

[...] 

> critically about science and what they read and hear.  Just what does the
> 98% number mean?  On the one hand you can say, "see how much we have in
> common".  On the other hand, you can make the point, that small changes can
> make big differences.  It's not bad to  discuss things like "the number"
> with people.  It makes people think a little more deeply about such things.

I thought you might be interested in a few more numbers and some refs.

The euchromatic regions of human and chimp DNA (i.e., where most of the
genes are) are about 98% similar by several criteria (hybridization,
sequencing, ...). Heterochromatic regions display considerable
divergence. 

The human-human similarity is about 99.9% (i.e., approximately one
difference in 1000 nucleotides).

But obviously some genes are more important than others in terms of
leading to phenotypic differences (homeotic genes, ...)

Some relevant refs:

Luke S, Verma RS. Human (Homo sapiens) and chimpanzee (Pan troglodytes)
share similar ancestral centromeric alpha satellite DNA sequences but
other fractions of heterochromatin differ considerably. Am J Phys
Anthropol. 1995 Jan;96(1):63-71.

Luke S, Verma RS. The genomic synteny at DNA level between human and
chimpanzee chromosomes.
Chromosome Res. 1993 Nov;1(4):215-9.

Springer MS, Davidson EH, Britten RJ. Calculation of sequence divergence
from the thermal stability of DNA heteroduplexes. J Mol Evol. 1992
May;34(5):379-82.

Wang DG, et al. Large-scale identification, mapping, and genotyping of
single-nucleotide polymorphisms in the human genome. Science. 1998 May
15;280(5366):1077-82.

Kaessmann H, Wiebe V, Paabo S. Extensive nuclear DNA sequence diversity
among chimpanzees.
Science. 1999 Nov 5;286(5442):1159-62.


--
Anders Gorm Pedersen, Ph.D. (gorm at cbs.dtu.dk)
Technical University of Denmark