Genome 'treasure trove'

We are more like a mouse than we thought

The first detailed look at the human genome has revealed a few surprises.

From a genetic perspective, all humans are Africans, either residing in Africa or in recent exile

Svante Paabo, Anthropologist

Not only do we have fewer genes than predicted but we are also astonishingly alike. Every person on Earth shares 99.99% of the same genetic code with all other people.

The biological difference between individuals amounts to a fraction of the three billion letters in the human genetic code.

"You and I differ by 2.1 million genetic letters from each other," said Dr Craig Venter, who led the private bid to crack the human code.

"Probably only a few thousand of those differences account for the biological differences between us, which means we all are essentially identical twins - even more than I thought."

Shared roots

The unveiling of the genetic data confirms that there is no scientific basis for the concept of race.

People from different racial groups can be more genetically similar than individuals within the same group. Genetic studies show that there is more variability in the gene pool in Africa, than outside.

We only have about 30,000 genes

"From a genetic perspective, all humans are therefore Africans, either residing in Africa or in recent exile," said Dr Svante Paabo of the Max Planck Institute of Evolutionary Anthropology, Leipzig, Germany.

The work also raises philosophical questions about the planet we share with creatures surprisingly similar to ourselves.

The challenge for scientists is to explain how a sophisticated human can be built from around 30,000 genes, fewer than for a grain of rice, and only a few hundred more than a mouse.

Worms and flies

"We can now start seriously investigating how it is that humans, who we think are so complex, can manage with only a relatively modest number more genes than worms and flies," said Martin Bobrow, a professor of medical genetics at Cambridge University, UK.

We are confirming Darwin, it's great to be getting the molecular correlates of what Darwin hypothesised 150 years ago

Sir John Sulston

Scientists say the treasure trove of information from the human genome will dramatically increase knowledge of ourselves.

Our genetic similarity to other creatures is firm proof of Charles Darwin's theories on the unity of life.

"We are confirming Darwin, it's great to be getting the molecular correlates of what Darwin hypothesised 150 years ago," said Sir John Sulston, who spearheaded the UK side of the Human Genome Project.

Joint publication

Researchers believe the key to the differences between humans and worms lies in the functions of some human genes and the proteins they control.

"We know that as we move up the ladder of complexity from the single cell creatures, through small animals like worms and flies, and up to us, what we are adding on is control genes," said Sir John Sulston.

Science is publishing one of two human genome studies

"We are not adding so many new genes performing new functions - what we are doing is to increase the variety and subtlety of genes that control other genes."

The Human Genome Project, a public consortium of scientists from the United States, Britain, Japan, France, Germany and China, are publishing the first analysis of the human genome in the scientific journal Nature.

A similar sequence deciphered by US company Celera Genomics will appear in the journal Science.