Investigating the Genetic Origins of the Platypus’s Weirdness

John Lewin, Platypus, 1808

From London Review of Books:

Of all the mammals, the naturalist George Shaw (no relation) wrote when he first described it in 1799, the platypus ‘seems the most extraordinary in its conformation’, exhibiting ‘the perfect resemblance of the beak of a duck engrafted on the head of a quadruped’. The specimen looked so like a taxidermic prank that ‘I ought perhaps to acknowledge that I almost doubt the testimony of my own eyes.’

Nevertheless, he duly classified it as a mammal despite its beak, ‘which verifies in a most striking manner the observation of Buffon: viz. that whatever was possible for Nature to produce has actually been produced.’ The apparently hybrid nature of the platypus had been recognised long before. An Australian Aboriginal Dreamtime story identifies the platypus as the offspring of a duck and a water rat. Early European colonisers of New South Wales called them ‘duckmoles’.

Last week, the first near-complete platypus genome was published. This is an impressive achievement. Animals and plants have their DNA bundled up in tangles inside chromosomes (fruit flies have eight chromosomes, humans have 46, dogs have 78 and platypuses have 52). To read the DNA sequence – the As, Ts, Cs and Gs – you have to break the chromosomes apart into tiny pieces. You’re then left with the job of computationally placing the pieces back together.

“Platypuses do it differently”, Liam Shaw, London Review of Books