I haven't contributed a single thing to the platypus genome project, but since my desk sits one floor above where people and robots broke the platypus DNA into chunks, cloned
those chunks into bacteria, sequenced the pieces of DNA, and used massive amounts of computing power to assemble the stretches of sequence into a complete genomic whole, I'm going to consider myself somewhat of an authority on the subject and tell you what's wrong with other people's ideas about the platypus.
The genome sequence of the platypus was published Thursday in Nature
, and from the press headlines, you could be excused for thinking that genomics has in fact confirmed that the platypus is a freak of nature: part bird, part reptile, and part mammal. The animal certainly looks like it - the platypus has the webbed feet and bill of a duck, and venomous spines and rubbery eggs that remind us of reptiles, but it has fur and feeds its young with milk, so it must be a mammal. The confusing press headlines might even lead you to believe that we sequenced the platypus genome just to figure out what this thing is, when the truth is, as we'll see below, that the genome sequence has essentially confirmed what evolutionary biologists have already deduced about the position of the platypus on the tree of life.
Is the platypus part bird, part reptile part mammal, an amalgam
of very different groups of animals? Is it a primitive mammal that resembles the early ancestors of all mammals? Can we figure out just what this creature is by gazing at its genome?
Photo Credit: Stefan Kraft, courtesy of the Wikipedia Commons