The first detailed genetic comparison between humans and chimpanzees shows that 96 per cent of the DNA sequence is identical in the two species. But there are significant differences, particularly in genes relating to sexual reproduction, brain development, immunity and the sense of smell.

An international scientific consortium publishes the genome of the chimpanzee, the animal most closely related to homo sapiens on Thursday in the journal Nature. It is the fourth mammal to have its full genome sequenced, after the mouse, rat and human being.

Some of the scientific analysis of the 3bn chemical “letters” of the chimp’s genetic code focused on its remarkable closeness to the human genome. After 6m years of separate evolution, the differences between chimp and human are just 10 times greater than those between two unrelated people and 10 times less than those between rats and mice.

But most scientists are concentrating on the differences. The vast majority of these probably have little biological significance, said Simon Fisher of the Wellcome Trust Centre for Human Genetics at Oxford: “The big challenge for the future is to pinpoint the tiny subset of differences that account for the origins of unusual human traits, such as complex language.”

The preliminary evidence suggests that the outstanding size and complexity of the human brain owes less to the evolution of new human genes than to the different way existing genes produce proteins as the human brain grows in the foetus and during infancy. Genes for transcription factors – molecules that regulate the activity of other genes and play a vital role in embryonic development – are evolving more quickly in humans than in chimps.

Three key genes involved in the human inflammatory response to disease are missing in chimps, which may explain some of the differences between the two immune systems. On the other hand humans have lost a gene for an enzyme that may protect other animals against Alzheimer’s disease.

The clearest differences to emerge from the analysis are in the Y (male) sex chromosome. While the human Y chromosome has maintained its count of 27 active gene families over 6m years, some have mutated and become inactive on its chimp counterpart.

This finding contradicts the popular view that the human Y chromosome is withering away because it has no genetic “mate” with which to swap genes – a process that repairs damaged DNA on other chromosomes. Presumably an alternative repair mechanism has evolved in humans but not in chimps.

David Page of the Whitehead Institute for Biomedical Research suggested that mating habits in the two species might explain the difference. Because male and female chimps mate with multiple partners there is stronger selective pressure on sperm-producing genes and conversely less pressure on evolution to preserve other genes on the Y chromosome in the apes than in largely monogamous humans.
news.ft.com

WASHINGTON – Chief executives at U.S. defense contractors have seen a 200-percent pay raise since the Sep. 11, 2001 terrorist attacks, widening the chasm between compensation in the corner office and wages on the factory floor, a new report said Tuesday.

Average CEO pay–$11.8 million in salary, stock options, bonuses, and incentives–rose last year to 431 times what the average worker earned, $27,460, according to the report from the Washington, D.C.-based Institute for Policy Studies and Boston-based United for a Fair Economy. In 2003, CEOs had made 301 times their average employees’ pay.

The ratio had peaked at 525-to-1 in 2001.

”If the minimum wage had risen as fast as CEO pay since 1990, the lowest paid workers in the U.S. would be earning $23.03 an hour today, not $5.15 an hour,” the research and advocacy groups said.

The report charged that individual CEOs have profited from the Iraq War, with huge average raises at the biggest defense contractors. To arrive at this conclusion, it looked at 34 of the top 100 defense contractors of 2004. While most firms in the larger group were privately held, the 34 included in the report were publicly traded, meaning that their financial results were easier to research.

The 34 companies covered by the report–firms including United Technologies, Textron, and General Dynamics–made at least 10 percent of their revenues from defense contracts.

At these firms, average CEO pay rose 200 percent from 2001 to 2004–as compared to seven percent for all CEOs.

Examples cited in the report include that of David Brooks, CEO of bulletproof vest maker DHB Industries, who earned $70 million in 2004, up 3,349 percent from his 2001 compensation of $525,000.
commondreams.org