We have a huge number of genes in common. But this also means only a few genes are responsible for the unique traits that make us human, says Dr Easteal, head of the human genetics group at the John Curtin School of Medical Research in Canberra. For the first time, identifying these genes has become a possibility. The explosion in knowledge from the human genome project has made it feasible to compare the DNA of humans and apes, bit by bit, says Dr Easteal. In this five-part series, the Herald talks to Australian researchers working on the big scientific questions of the 21st century.
Genetic differences discovered so far are much more mundane.
For example, humans lack a sugar molecule found on the surface of every cell of all other apes. This could explain why we are more susceptible than them to infections such as malaria. Dr Easteal believes many of the genes for human-ness will turn out to have more than one function, with important medical consequences. Genes associated with language development, for example, are thought to be linked to schizophrenia. Genes governing cell division, which allowed our bodies and brains to grow to their larger size, could be implicated with cancer, which apes rarely suffer.