Now, more than 200 years later, a team of scientists has determined the platypus’ entire genetic code. And right down to its DNA, it turns out, the platypus continues to strain credulity, bearing genetic modules that are in turn mammalian, reptilian and avian.

There are genes for egg laying — evidence of the animals’ reptilian roots. Genes for making milk, which the platypus does in mammalian style despite not having nipples. Genes for making snake venom, which the animal stores in its legs. And there are five times more sex-determining chromosomes than scientists know what to do with.

“It’s such a wacky organism,” said Richard Wilson, director of the genome center at Washington University in St. Louis, who led the two-year international effort, described online Wednesday in the journal Nature.

Yet in its wackiness, Wilson said, the platypus genome offers an unprecedented glimpse of how evolution made its first stabs at producing mammals.

(via feednews, chicagotribune)