Hi Ros,
Interesting find.
The article (probably unintentionally) highlights a problem that many supposed transitionals face: that is, they seem to violate evolutionary principle at the same time as they are being heralded for proving the validity of evolution.
Quote:"Tiktaalik was probably an unwieldy swimmer," says John Maisey, a palaeontologist at the American Museum of Natural History in New York. It probably lived in shallow waters, says Maisey, only hauling itself on to land temporarily to escape predators. "Tetrapods did not so much conquer the land, as escape from the water," he says.
The implication of this is that the 'evolving' critter rendered itself unfit to live successfully in the water, so it had to find other habitat.
If the 'evolving' limbs from fins made Tiktaalik less able to survive and thrive in it's (then) present watery habitat, then it would seem that right off the bat, the supposed evolutionary advance conferred, not an advantage but a DISadvantage upon Tiktaalik.
The same could be said of the commonly repeated jawbone-to-ear story of established evolutionary lore.
If the receding jawbone made it's owner less capable of feeding itself as it shrunk into a tiny bone in the ear, then the DISadvantage conferred upon the unfortunate would seem to come into play long before any real advantage could be realized by a well developed apparatus for auditory info gathering.
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Another interesting question is this: Tiktaalik was found in Canada. It was supposedly a dweller in shallow water, so how are we to suppose that it crossed oceans to inhabit other continents?
Did all land dwellers stem from this line in Canada?
Or (assuming the shalow water dwelling fish COULD somehow have made it to other continents) did this same scenario of water-to-land play out on several continents, evolutionary 'lightning' striking , as it were, many or multiple times to produce land dwellers on all the continents?
(Some have contended that structures such as the eye, for example, may have evolved independently in as many as 40 separate instances or MORE, but this simply stretches credulity.
Does anyone truly suppose that a complex structure such as an eye could have evolved to a high state of complexity and precise function, starting from scratch on 40 occasions?)