Of mice and men, and genes

The humble mouse holds a gene count to be reckoned with

By Douglas Herbert, CNN.com Europe writer

LONDON, England (CNN) -- The nature of an entity, Aristotle argued, lies in its essence.

What, then, would ancient Greece's peripatetic philosopher have made of Monday's genetic watershed that humans, for all their highbrow conceits, differ little in their essential make-up from a fruit fly or a mouse?

Unexpected news that the human blueprint derives from at most 30,000 genes (compared with as many as 140,000 originally surmised) may go a long way towards knocking homo sapiens off their evolutionary high horse.

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And that, observers say, may not be a bad thing.

"I hope it will have a humbling effect," said John Harris, the Sir David Alliance Professor of Bioethics at the University of Manchester.

"When we know that we share 45 or 50 percent of our genes with cabbages, it makes the whole of creation much more related, (and it makes us realise) that animals and plants are not radically different types of stuff."

Harris, echoing the view of many in the bio-ethics community, said the presence of fewer genes clearly leaves more scope for the environment -- the famous "nature versus nurture" argument -- to influence human personality.

What we can safely say in the aftermath of the latest genetic discoveries, Harris suggested, is that "a smaller number (of genes) are doing the same business as a larger number of genes" -- though just what business is still unclear.

Backers of genetic "determinism" -- the theory by which our actions are largely pre-ordained by genetic signals hot-wired to our DNA -- could suffer a setback in the face of evidence that our genetic code is much sparser than previously imagined.

"To the extent that they found fewer genes than they were looking for, it tends to undermine any sort of genetic deterministic perspective on human nature and what makes us what we are," said Carl Hoefer, a lecturer in philosophy at the London School of Economics.

Genetic screening less useful

Hoefer also expressed hope that the genome project would wean people from "simplistic" attempts to assess risk factors for certain types of behaviour -- say, heavy drinking -- based on genetic screening.

"If you are worried about alcoholism, a genetic screening test is going to be a lot less useful than taking a brief family history," Hoefer said.

Having fewer genes does not mean we are less complex as creatures -- but merely that our essence stems from myriad factors other than genetic instructions alone.

"Our complexity has arisen by a long history of evolution that led to humankind, the long gestation that we all have in our mothers' wombs, and the long, 18-year formation" to adulthood.

The discovery has met with a cautiously enthusiastic response from theological quarters as well.

Stephen Jenkins, a spokesman for the Church of England, which teaches that all men are God's creation, said he found the gene findings "intriguing."

If anything, Jenkins said, the genetic breakthrough reinforced the notion that human beings enjoy free will and the ability to use their intelligence to discover how things operate.

For Harris, at the University of Manchester, the genome project places the future evolution of the human race squarely in the hands of humans themselves, with all the responsibility such a burden entails.

Because the research suggests all humans share from 99.8 to 99.9 percent of the same genes, Harris sees individual claims over personal entitlement to genetic information becoming harder to justify.

Likewise, he says, the discovery "will remind us, very forcibly and in a very graphic way that there are no such things as old families and better or worse pedigrees." Distinctions based on race, he said, will be exposed for what they are -- false social constructs.

For all the gene sharing, however, people are likely to retain their unique qualities, even in an age of cloning, as the diversity of the human experience is brought to bear.

"We will never create another (Vladimir) Lenin," Harris said, "because he was born in the 1870s in pre-revolutionary Russia. We don't have available his mother's uterus, his parents to bring him up, the school system he went into, a situation where the thought of Karl Marx will seem fresh and exciting. … Whatever we do, we will never get Lenin back."

Landmark gene studies released
February 12, 2001
Human genome to go public
February 9, 2001
Genetically modified monkey could be key to curing some diseases
January 11, 2001
The promise and perils of the human genome
June 27, 2000

Nature science journals
The Human Genome Project
Celera Genomics
National Human Genome Research Institute
Genetic Determinism

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