No gentle giant, ABC/Reuters, August 16, 2006. ...
[Graphic: paleontologist Erich Fitzgerald inspects the skull of Janjucetus hunderi, Sydney Morning Herald
This post will be in two parts: this part #1, being news items and my comments on a primitive baleen whale that had no actual baleen and part #2, how this does not fit Darwin's explanation of the origin of baleen by "natural selection" in "finely graduated steps, each of service to its possessor."
I had planned to have as part #3, a further clarification of my Theory of Progressive Mediate Creation by the supernatural intervention of God through mutations, but I have decided to post that at a later date in a post (or series of posts) with a subject line that better reflects that topic.]
Blue whale ancestor 'was no gentle giant' A ferocious-looking fossil with sharp teeth found in Australia shows that ancestors of today's toothless blue whales were not all "gentle giants", a report says. The 25 million-year-old fossil is of an early type of baleen whale that was probably up to 3.5 metres long. This group of whales includes modern humpback whales, minke whales and blue whales. The animals feed via baleen - comb-like plates in their mouths that filter plankton from sea water. "This bizarre, new baleen whale did not even have baleen," Erich Fitzgerald, of Monash University in Australia, said. "It had teeth and was a powerful predator that captured large fish, perhaps sharks, maybe even other whales. "Some of the early baleen whales weren't gentle giants." Most scientists have believed that baleen whales quickly evolved baleen for feeding on tiny fish and plankton after breaking from a common ancestor with toothed whales almost 40 million years ago. Modern toothed whales include dolphins, killer whales and sperm whales - the species made famous as the bane of Captain Ahab in Herman Melville's Moby Dick. "This rewrites the picture of baleen whale evolution," Mr Fitzgerald said. The fossil was found near Jan Juc in Victoria and has been dubbed "Janjucetus". The report, which has been published in the journal Proceedings of the Royal Society B, says its sharp teeth were about three centimetres long . It also had large eyes, which were apparently suited for hunting. Blue whales, which can exceed 150 tonnes and grow longer than 30 metres, are the largest creatures ever to inhabit the earth - bigger than any dinosaur. Whales evolved from land mammals, where their closest relative is the hippopotamus. ... [Note: 1) it was previously "believed that baleen whales quickly evolved baleen ... after breaking from a common ancestor with toothed whales almost 40 million years ago;" yet 2) ~15 million years later, this "25 million-year-old fossil" of a "baleen whale did not even have baleen" (my emphasis).]
Discovered: Aussie T-rex of the deep, Sydney Morning Herald , August 16, 2006 ... A fossil of a creature with huge razor-sharp teeth that used to "chomp" through its prey off Australia's southern coastline about 25 million years ago has been found. But what has excited Australian paleontologists and prompted a re-drawing of the world's evolutionary charts is the fact this ancient predator was a baleen whale - the species that today catches tiny shrimps and krill using only a sieve of coarse hair. ... The complete skull was unveiled today at the Melbourne Museum, where it was also labelled one of the most important marine mammal fossil finds in Australia. "It literally rewrites our understanding of the evolution of baleen whales," Mr Fitzgerald, 25, said today. "It is an ancient baleen whale, so primitive, so primeval, that it has teeth, and it was not a passive gentle giant like today's blue whale or the humpback whale but a voracious predator that captured large fish." ... [Note: 3) that this was an "ancient baleen whale, so primitive, so primeval, that it has teeth" will require "a re-drawing of the world's evolutionary charts" because of 4) "the fact this ancient predator was a baleen whale." (my emphasis).]
Whale fossil sports fierce teeth, BBC, 16 August 2006, Elli Leadbeater ... The small, large-eyed baleen whale used a fully developed set of teeth to hunt its prey. Scientists had thought that two groups of ancient whales evolved drastically different eating habits more than 34 million years ago. They believed ancient whales that fed by filter feeding evolved to become today's enormous but passive baleen whales, and those that hunted became the ocean's giant predators, the toothed whales. Toothed whales include the killer whale, sperm whale and dolphin, whereas baleen whales are typified by the humpback and blue whale. The new specimen shows that ancient baleen whales probably hunted prey like their toothed relatives. ... Baleen is made of a substance called keratin, just like our fingernails and hair. ... lead researcher Erich Fitzgerald [said] .... "Surprisingly, it appears that the original features of baleen whales did not include the filter-feeding apparatus." ... "It's always been known that ancient baleen whales had teeth, but this fossil is very important because it looks like the teeth were not used for filter feeding," commented Mark Uhen, head of research at the Cranbrook Institute of Science in Michigan, US. ... [Note: 5) that "the original features of baleen whales did not include the filter-feeding apparatus." (my emphasis).]
The sharp-toothed past of filter-feeding whales, New Scientist, 16 August 2006, Emma Young ? The discovery of Janjucetus hunderi provides a new insight into the evolution of the two modern whale groups. ... "This provides us with a really good idea of what the most ancient baleen whales were like," says researcher Erich Fitzgerald ... And it had a large set of teeth with no evidence of the comb-like fringes used by other baleen whales to filter their food from seawater. ... This new species is not the ancestor of modern baleen whales, however. The most ancient baleen whale fossil, found in Antarctica, is 10 million years older. Instead, J hunderi belongs to an unrecognised evolutionary sidetrack, which no one had suspected existed. [Note: 6) the claim that "This new species is not the ancestor of modern baleen whales" because; 7) "The most ancient baleen whale fossil ... is 10 million years older" (my emphasis). As an aside, this would then rule out the Cretaceous ~120 mya `feathered' dinosaurs of China being ancestral to birds which date from Archaeopteryx in the Jurassic ~145 mya. ]
A bizarre new toothed mysticete (Cetacea) from Australia and the early evolution of baleen whales, Proceedings of the Royal Society B, Erich M.G. Fitzgerald ? Extant baleen whales (Cetacea, Mysticeti) are all large filter-feeding marine mammals that lack teeth as adults, instead possessing baleen, and feed on small marine animals in bulk. The early evolution of these superlative mammals, and their unique feeding method, has hitherto remained enigmatic. Here, I report a new toothed mysticete from the Late Oligocene of Australia that is more archaic than any previously described. Unlike all other mysticetes, this new whale was small, had enormous eyes and lacked derived adaptations for bulk filter-feeding. Several morphological features suggest that this mysticete was a macrophagous predator, being convergent on some Mesozoic marine reptiles and the extant leopard seal (Hydrurga leptonyx). It thus refutes the notions that all stem mysticetes were filter-feeders, and that the origins and initial radiation of mysticetes was linked to the evolution of filter-feeding. Mysticetes evidently radiated into a variety of disparate forms and feeding ecologies before the evolution of baleen or filter-feeding. The phylogenetic context of the new whale indicates that basal mysticetes were macrophagous predators that did not employ filter-feeding or echolocation, and that the evolution of characters associated with bulk filter-feeding was gradual. [Note that this 8) "refutes the notions that all stem mysticetes were filter-feeders," and 9) that the origins and initial radiation of mysticetes was linked to the evolution of filter-feeding" (my emphasis).
I don't include it as a point, Fitzgerald's claim that this fossil is evidence that "the evolution of characters associated with bulk filter-feeding was gradual," as it shows the exact opposite, at least in the Darwinian sense of "slow gradualism" :
"To 'tame' chance means to break down the very improbable into less improbable small components arranged in series. No matter how improbable it is that an X could have arisen from a Y in a single step, it is always possible to conceive of a series of infinitesimally graded intermediates between them. However improbable a large-scale change may be, smaller changes are less improbable. And provided we postulate a sufficiently large series of sufficiently finely graded intermediates, we shall be able to derive anything from anything else, without invoking astronomical improbabilities. We are allowed to do this only if there has been sufficient time to fit all the intermediates in. And also only if there is a mechanism for guiding each step in some particular direction, otherwise the sequence of steps will career off in an endless random walk. It is the contention of the Darwinian world-view that both these provisos are met, and that slow, gradual, cumulative natural selection is the ultimate explanation for our existence. If there are versions of the evolution theory that deny slow gradualism, and deny the central role of natural selection, they may be true in particular cases. But they cannot be the whole truth, for they deny the very heart of the evolution theory, which gives it the power to dissolve astronomical improbabilities and explain prodigies of apparent miracle." (Dawkins R., "The Blind Watchmaker," Norton: New York, 1986, pp.317-318. My emphasis)
If there was evidence of a sequence of "finely graduated steps" of "filter-feeding" from the earliest baleen whales, along the lines that Darwin argued for (see part #2) then this would support that claim. But since this is the most morphologically "ancient baleen whale, so primitive, so primeval, that it has teeth" yet it was still in existence ~25 mya, i.e. ~15 my after the presumed toothed (odontocetes)-baleen (mysticetes) whale split-which I accept happened, then this is evidence that the origin of baleen occurred in a shorter timeframe, and therefore was not, or at least less, "gradual" in the above Darwinian sense. As the first article says,before this find, "Most scientists have believed that baleen whales quickly evolved baleen for feeding on tiny fish and plankton after breaking from a common ancestor with toothed whales almost 40 million years ago" (my emphasis)!]
Continued in part #2
Stephen E. Jones, BSc (Biol).
`Evolution Quotes Book'
Post a Comment