Researchers take another look at Platypus DNA, and yes, still weird

Waddle, squirm, wander, dig, lay eggs. There is no shortage of verbiage to describe monotremes – the taxonomic order composed of only two animals, the platypus and the echidna. Rattling off the many bizarre traits of these creatures is trope in media coverage – and it’s almost impossible to avoid, as they are mammals that lay eggs and sweat milk, among other things weird features.

But perhaps the easiest way to describe the tremendous evolutionary success of monotremes is to go straight into their DNA.. This is exactly what a team of 40 researchers from Australia, China, Japan, Denmark and the United States did in a recent study of the genomes of monotremes. Their conclusions are published in the journal Nature.

Platypus’ first draft and genome sequence analysis has arrived in 2008. The recent article includes aupdating the quality of this sequence and the very first echidna genome (for some reason, the echidna is always second violin after the platypus). Interestingly, monotremes fall somewhere between oviparity and viviparity – referring to the place of development of embryos, in eggs, or in the body of the parents. This ni-ici-ni-thereness is reflected in the protein dependencies of animals.

“During their short egg incubation period, they retained one of the three main egg proteins used to make the yolk of chickens,” said Marilyn Renfree, zoologist at the University of Melbourne and co. – study author, in a press release, “but after hatching, the platypus and echidna have complex milk like other mammals to support their young during their long lactation.”

Monotremes are a special branch of the tree of life, in that they help fill in the gaps in our understanding of when animals with certain traits separate from each other.

“Effectivelyhe platypus belongs to the class Mammalia. But genetically, it’s a mixture of mammals, birds and reptiles, ”Guojie Zhang, a biologist at the University of Copenhagen and co-author of the recent study, said in a press release. “He has retained many of the original characteristics of his ancestors – which likely contribute to his ability to adapt to the environment in which they live.”

And animals need that extra boost. The Australian bushfires did last year efforts to track the platypus more difficult, and all the more imperative. (A population was rescued and returned to the wild this summer.) Having the echidna genome sequenced will allow genetic management of an equally threatened species. After all, we cannot let our strange illustrious creatures follow the thylacine and the dodo path.