Whale Fossils: Challenge or Support for Evolution?
When most fossils consist of small shelly creatures, finding a whale is indeed big news. Two whale fossil discoveries on opposite sides of the world are spectacular and puzzling. Do they support the theory that whales evolved from land mammals?
Aye: Egyptian Whales: PhysOrg announced triumphantly, “Whale fossils show important characters of the transition to water.” Easier said than proved. Limestone plates quarried in Egypt were found to bear fossils of Aegyptocetus tarfa, a putative whale transitional form. Owen Gingerich [U of Michigan] is usually nearby wherever whale-evolution fossils are found, and this was no exception. He said this species, alleged to be 40 million years old, “falls right in the middle of what we know about the evolutionary transition of whales from land to sea.” In what ways? “The transitional characters present in this species include a retained sense of smell (which is usually lost in aquatic mammal lineages), an enhanced ability to hear (a characteristic of later and modern whales), and the ability to still haul itself out of the water, similar to modern seals.” The holotype was discovered and named by Gingerich. Wikipedia says Aegyptocetus is classified under Protocediae, “a diverse and heterogeneous group of cetaceans known from Asia, Europe, Africa, and North America.” How these diverse fossils relate to one another, let alone to whales, is not clear from the limited write-up on this genus. The article said nothing about how such a large mammal got buried in fine limestone.
Nay: Chilean Whales: Watch a one-minute video clip on the BBC News about a spectacular assemblage of fossil whales being uncovered in Chile. Dozens are expected in this fossil graveyard. The workers exceeded expectations by finding 15 whales in 15 days. Remains of sharks, dolphins and seals have also been found, with many of the skeletons intact and complete. Paleontologist Sol Square calls this a “discovery of global importance. There’s never been a find of this size or this diversity anywhere in the world.” That boast, though, seems overshadowed by a discovery announced in Geology in 2004 of 346 whale fossils buried in diatomaceous earth (see 2/02/2004). That discovery was published by creation geologists who believe a global flood was responsible for their burial.
Update 11/19/2011: A report on PhysOrg says it is possible all these whales, in an area covering two football fields, died simultaneously. The article also states that hundreds more may be found in the area. The paleontologists seem puzzled trying to explain the mass burial. “Chilean scientists together with researchers from the Smithsonian Institution are studying how these whales, many of the them the size of buses, wound up in the same corner of the Atacama Desert,” one of the driest spots on Earth. Hans Thewissen, a spokesperson on ancient whales, thinks they were buried over a long period of time, but offered an alternative scenario that they were stranded in a lagoon whose outlet got cut off. "Subsequently the lagoon dries up and the whales die,” he said. Waiting for sediments to accumulate gradually over whales seems highly improbable, though, considering how quickly stranded whales decompose today. Besides, Nature on Nov. 10 reported that “ancient whales were worm food.” Sea worms are capable of boring through whale bone, leaving little evidence of dead whales remaining on the ocean floor. By contrast, “the Chilean fossils stand out for their staggering number and beautifully preserved bones.”
Mammal puzzles: The evolution of whales has to be fitted to the bigger Darwinian picture of the evolution of mammals. On that subject, Science praised the work of Meredith et al. who produced a new mammal phylogeny (28 October 2011: Vol. 334 no. 6055 pp. 458-459, doi: 10.1126/science.1214544). Kristofer M. Helgen rightly asked, “what group of mammals was the closest relative of primates, or bats, or whales?” Evolutionists have long puzzled over the bad fit between morphological and genetic data. Meredith’s magic solution that made everything come together neatly was to use a “relaxed clock approach.” Helgen described this as something that “allows the tremendous variability in rates of evolution across the mammal tree of life to be taken into account.”
Remember that with evolution, the story comes first, then the data. Gingerich is an evolution huckster who specializes in whales. We’d like to have him tell us how hundreds of whales got quickly buried in Peru and Chile. How many other whale fossil graveyards lie undiscovered between those sites? And how did his pet transitional form get buried in limestone in Egypt? Whales don't just sit on the sea floor waiting for microscopic particles of lime to cover them over millennia. They are quickly scavenged by other animals all the way to the bone. Instead of divining for the Spirit of Charlie, Gingerich should be thinking seriously about how these large creatures suffered catastrophic fates in large numbers. Meanwhile, give him a clock that keeps rigid time.