Natural Wonders & Evolution of whales; new discovery (Evolution)

by David Turell @, Friday, September 13, 2019, 18:36 (69 days ago) @ dhw

DAVID: I don't have an answer other than to propose God helped with the newly required designs for aquatic life. For example how did the snake handle the extra salt? Like the whales? There is more to jumping into salt water, with the new physiological requirements. I seriously doubt cell committees can handle the design requirements, based on current epigenetic studies of adaptations.

dhw: Why “helped” with designs? Do you think he popped in to give these creatures a poke and a prod as their cell communities struggled to obey the sea-snake-respiratory-system-instructions you seriously believe he had implanted in the first cells 3.8 billion years ago? Yes, we know you seriously doubt the whole concept of intelligent cell communities, just as I also seriously doubt your fixed belief that your God turned the pre-whale’s legs into flippers before pushing it into the water because otherwise life could not have gone on until he designed H. sapiens, the only thing he wanted to design. (my bold)

There is a new whale finding : possible dog= paddling style at early stages of aquatic life:

https://www.newscientist.com/article/2216397-early-whales-swam-doggy-paddle-across-the-...


"Whales are descended from hoofed land animals similar to modern deer, so the first proto-whales to venture into the water presumably used all four limbs for propulsion, as four-legged animals do today. More modern whales swim by undulating their entire bodies and only use their front limbs – their flippers – for steering. This crucial evolutionary transition took place between 50 and 35 million years ago.

"We do not fully understand what happened to early whales’ arms during this time because we don’t have many fossils. “We only know the forelimbs for a few species,” says Vautrin.
His team has now found a new one. Vautrin and his colleagues unearthed a partial skeleton of an early whale called a protocetid in Senegal. The fossil includes two vertebrae, two ribs, fragments of the feet and tail – and most of an arm.

"Dated at between 43 and 41 million years old, it sits in the middle of whales’ transition to marine life. “We are far from the earliest whale, but we are a few million years before the real whales,” says Vautrin.

"Even at this relatively late stage in the evolution of early whales, it seems the animal was using its arms to propel itself. The bones show the protocetid’s arm had powerful muscles and the ability to bend at the elbow.

"This suggests the animal used it arms — and presumably legs too — to swim, in a way that could have resembled a modern dog. In truth, it is not clear exactly what ‘stroke’ the animal used. The shoulder bones have not been found, so we can’t tell whether the arm could move sideways or just forwards and backwards. “We don’t know if it’s just crawl or more like butterfly,” says Vautrin.

"These forms of swimming are not as efficient as that used by modern whales, but it does not seem to have stopped the protocetids travelling great distances. The first whale-like animals are only known from the vicinity of India, but the new fossil shows that the protocetids reached the west coast of Africa.

"Early whales probably tried many different ways of swimming, says Vautrin. He suggests that the first group to evolve the modern undulating mechanism may have out-competed the others."

Comment: What is new is an explanation that forelegs may have dog-paddled for propulsion before changing into steering mechanism, which changes the anatomic arrangements of bones and muscles. What is not known is whether these protowhales swam on the surface or were more aquatic, and developed the required complex physiological changes. I still view God doing the design changes which are obviously stepwise. My bold of your sentence is not as I have imagined arm to flipper changes. There were stages as designed by God from hoof to flipper. A pure hoof would have very little propulsion so I assume they entered the water with some early changes.


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