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Genome scan shows human-chimp differences Variations hint at how our lifestyle is reflected in our
genes. 12 December 2003 JOHN WHITFIELD
Genes involved in smell and hearing are significantly different between humans and chimpanzees,
researchers have discovered. The finding could be a starting point for understanding what separates
us from our closest relative.
"This tells us the types of genes that are important for our differences," says Michele Cargill of
the biotech company behind the comparison, Celera Diagnostics in Alameda, California. But the list
does not tell us what makes us human, she cautions: "Just finding a change in one protein gives us
no idea of how it affects the whole animal."
The human and chimp genomes are about 99.2% identical. In the most important bits of the genome,
this figure rises to 99.5%. Yet Cargill and her colleagues believe that they have seen the
fingerprint of evolution in these small DNA differences.
The researchers compared the sequences for more than 7,500 human, chimpanzee and mouse genes,
compiled by the genome projects for each species. Matching the two primates against the mouse
revealed whether chimp or man has changed most from the ancestral starting point shared by the
three mammals.
All DNA sequences change over time as mutations build up. To spot the effects of evolution, the
researchers looked for genes that had altered more during the five million years since human and
chimpanzee split than would be expected by chance. About 1,500 genes seem to have been affected by
selection, this analysis showed.
"It's the first genome-wide comparison of humans and chimps," says geneticist Svante Paabo of the
Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany. "It will allow us to form
many interesting hypotheses about the crucial new features during human evolution."
But some scientists doubt that the differences studied are the work of evolution. There are so few
changes between human and chimpanzees, argues evolutionary biologist Adam Eyre-Walker, that
comparing single genes gives hardly anything to analyse.
"My gut feeling is that there aren't enough data here," says Eyre-Walker,
to combine information from many genes
Read the rest at Nature http://www.nature.com/nsu/031208/031208-15.html
Posted by Robert Karl Stonjek.
genes. 12 December 2003 JOHN WHITFIELD
Genes involved in smell and hearing are significantly different between humans and chimpanzees,
researchers have discovered. The finding could be a starting point for understanding what separates
us from our closest relative.
"This tells us the types of genes that are important for our differences," says Michele Cargill of
the biotech company behind the comparison, Celera Diagnostics in Alameda, California. But the list
does not tell us what makes us human, she cautions: "Just finding a change in one protein gives us
no idea of how it affects the whole animal."
The human and chimp genomes are about 99.2% identical. In the most important bits of the genome,
this figure rises to 99.5%. Yet Cargill and her colleagues believe that they have seen the
fingerprint of evolution in these small DNA differences.
The researchers compared the sequences for more than 7,500 human, chimpanzee and mouse genes,
compiled by the genome projects for each species. Matching the two primates against the mouse
revealed whether chimp or man has changed most from the ancestral starting point shared by the
three mammals.
All DNA sequences change over time as mutations build up. To spot the effects of evolution, the
researchers looked for genes that had altered more during the five million years since human and
chimpanzee split than would be expected by chance. About 1,500 genes seem to have been affected by
selection, this analysis showed.
"It's the first genome-wide comparison of humans and chimps," says geneticist Svante Paabo of the
Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany. "It will allow us to form
many interesting hypotheses about the crucial new features during human evolution."
But some scientists doubt that the differences studied are the work of evolution. There are so few
changes between human and chimpanzees, argues evolutionary biologist Adam Eyre-Walker, that
comparing single genes gives hardly anything to analyse.
"My gut feeling is that there aren't enough data here," says Eyre-Walker,
to combine information from many genes
Read the rest at Nature http://www.nature.com/nsu/031208/031208-15.html
Posted by Robert Karl Stonjek.