One of the facts about evolution that really blew my mind when I first learned about it was that whales had evolved from land mammals that had returned to the sea. Even though I had no formal training in biology beyond eighth grade, I was aware of course of the basic evolution story of how we all evolved from ocean organisms but the idea that at some point the process got reversed for some branches of the evolutionary tree and they become sea-dwelling creatures again just captured my imagination and I have posted about it before.
This animation shows how a reconstruction, based on the fossil record, of how it happened.
So I am always interested in new developments in this area and now comes along a report of the fossil of a new species of four-legged whales that weighed about 600kg and three meters (10ft) in length that was found in Egypt’s Western desert and lived around 43 million years ago.
The partial skeleton was found in Egypt’s Fayum Depression and analysed by scientists at Mansoura University. Although the area is now desert, it was once covered by sea and is a rich source of fossils.
“Phiomicetus anubis is a key new whale species, and a critical discovery for Egyptian and African palaeontology,” the study’s lead author, Abdullah Gohar, told Reuters news agency.
While this is not the first time the fossil of a whale with legs has been found, the Phiomicetus anubis is believed to be the earliest type of semi-aquatic whale to be discovered in Africa.
The first whales are thought to have first evolved in South Asia around 50 million years ago. In 2011, a team of palaeontologists in Peru discovered a 43-million-year-old whale fossil with four legs, webbed feet and hooves.
You can read the paper here.
It is such an amazing thing to consider. I feel sorry for all those evolution deniers who will never feel the sense of wonder that I feel when I think of how simple laws of science can produce such a complex array of organisms.
Depends on your definition of ‘simple’. The Standard Model of particle physics, Newtonian mechanics, and Einstein’s field equations are certainly beautiful, and yield some results fairly easily, but things can get horribly complicated very quickly. It’s only in the last decade or so that we’ve been able to calculate the proton mass to within a few percent, using sophisticated numerical techniques. And that’s still a long way from chemistry or biology.
I have read and seen illustrations of whales that sometimes are found with bones in their flippers or bodies that resembles legs or feet. If true, then apparently some genes still exist that occasionally are expressed, even though they don’t create real legs or feet, so no whales are going to come lumbering out of the sea to terrorize beachgoers (Attack of the Walking Killer Whales might be an interesting plot to sell to a cheap horror movie production company), but it’s still fascinating that such evidence of whale evolution exists.
In the very-early 2000s (like 2002/2003 timeframe), I was briefly stationed in Norfolk and took the kids to Virginia Beach, where we spent the day in the museum and aquarium. Overall it was a great place, but when we wandered through a room with skeletons of dolphins hung from the ceiling, one of the kids noticed the dolphin’s flippers, with what looked like arm bones and fingers…just like people. When one of the kids asked about it, I said dolphins are mammals just like people are mammals and therefore our bones look similar because they worked the same way. Dolphins once lived on land, but later went into the sea, so their “arms” evolved into flippers.
We were approached by a docent to warn us that there’d been several complaints from the other patrons about evolution and to please stop talking because this was a Christian museum. Whew. Lotta crazy down south.