This New Year as the weather turns chilly, spare a thought
for the orphan genes. Around a third of all genes in all genomes have no
relatives – no parents, no family tree, no evolutionary past. They’ve had a
tough time of it and they’re struggling for recognition.
Orphan genes are genes found in just one species (or a group
of closely related species) and nowhere else – the jellyfish gene that guides
the formation of stinging cells, the polar cod gene that prevents the fish from
freezing, and the fruit fly gene that helps it to fly. They may even have
stimulated the evolution of human brain. They’re innovative and they’re
everywhere – orphan genes have been found in all of the genomes examined so far.
