A massive outpouring of data about the DNA of chimpanzees - our closest living relative - including news that we share up to 99 per cent of the primate's genome sequence raises hopes for advances in human health.
Mapping the DNA of the chimp is a "historic achievement" and key to figuring out what makes us human, according to Francis Collins, director of the U.S.-based National Human Genome Research Institute, which partly funded the project.
The detective work conducted by 67 international scientists who are part of the Chimpanzee Sequencing and Analysis Consortium published their findings in the latest issue of the journal Nature.
Already scientists have published the genome sequences for an array of species including the roundworm, honey bee, mouse, rat, and humans.
The chimp blueprint locates three billion building blocks of life and suggests the genetic differences between us and the primate are just 10 times more than between any two humans. Still, the researchers point out that there are tens of millions of differences between the chimp and a human, but the finding doesn't explain why humans developed complex language and walk upright.
"That's just giving us the raw materials to work with," to Ken Dewar of McGill University and Génome Québec Innovation Centre.
Understanding the differences is the key to finding out what makes us human, he said. But researchers are only slowly identifying sequences and signatures in human DNA as they attempt to understand what each gene is made of and what they do. But mostly, explained Dr. Dewar, who took part in the human and mouse genome sequencing projects, researchers have no idea what our genes do.
"It's frustrating," he said, "A lot of it is trial and error."
In an accompanying commentary in the journal, Wen-Hsiung Li and Matthew Saunders of the University of Chicago suggest that since it has only been six million years since ancient humans and chimps split from a common ancestor, they suspect that few mutations with large effect are responsible for what separates humans from chimps.
Scientists found that humans and chimps share between 96 and 99 per cent of their genome sequences depending on how they are compared.
Similarities including those involving perception of sound, which have gone through rapid changes over time compared with other mammals
They've also found humans and chimps share more harmful mutations in their genomes, an evolutionary strategy that appears to have made primates readily adaptable to changes in the environment.
But they also found where the similarities end.
Human DNA has the tell-tale signs of strong natural selection, while chimpanzees do not.
Chimps also lack some genes involved in inflammation, but humans lack function in a gene that protects other animals against Alzheimer's disease.
These findings could have implications in the lab.
In an accompanying commentary titled "The ethics of research on great apes" a group of scientists call for guidelines for the ethical treatment of captive animals in the lab. There are about 3,000 in labs, zoos and housed by individuals. They also urge science never to genetically manipulate chimps as science has in breeding transgenic mice.
The U.S.-based National Institutes of Health, which has placed a moratorium on breeding in captivity of chimps, gorillas, orangutans and bonobos - referred to collectively as the "great apes."
But in another commentary in the journal, still other researchers call for lifting the moratorium as "essential to preserve this unique resource" which they contend is "needed to solve some of the most important global health problems of today and tomorrow."
Chimps were infected with hepatitis B and C viruses and were important in developing a vaccine against hepatitis B. They are used today to test vaccines for HIV.