Jurassic Mammal: Puzzle or Prize for Darwin?
Two recently-reported Jurassic mammal fossils can be seen as puzzles for evolutionary theory, or confirmations of it – depending on the reporter.Two new Jurassic fossils yield conflicting reconstructions of the mammalian tree. These divergent genealogies have profoundly different implications for the origin and early diversification of mammals.That’s the announcement in Nature (bold in the original) about two mammal fossils, one named Megaconus (large cusp) reported by Zhou et al., the other named Arboroharamiya (tree-dwelling haramiyad) reported by Zheng et al. The headline of a Nature News article moans, “Fossils throw mammalian family tree into disarray.”One would never know about the conflict reading Science Daily, though. Its headline announces, “New Proto-Mammal Fossil Sheds Light On Evolution of Earliest Mammals.” The article turned a puzzle into a triumph for evolution:A newly discovered fossil reveals the evolutionary adaptations of a 165-million-year-old proto-mammal, providing evidence that traits such as hair and fur originated well before the rise of the first true mammals.Another Science Daily piece announced, with no suggestion of doubt, that “complex structures can occur multiple times in evolution, independently of each other.” Laura Poppick at Live Science advertised Megaconus as “one of two recently described ancestral mammal fossils that provide a significant leap forward for research in early mammal evolution.” Science Now threw in a little anthropomorphism, saying that the animal “was among the first to try out mammalian features before falling into extinction while modern mammals rose.”How could all these reporters get the story so wrong? Nature was vexed that the fossils set back ideas on mammal evolution, not “provide a significant leap forward.” They throw the “mammalian family tree into disarray.” Why? Because they contradict each other:Two fossils have got palaeontologists scratching their heads about where to place an enigmatic group of animals in the mammalian family tree. A team analysing one fossil suggests that the group belongs in mammals, but researchers looking at the other propose that its evolutionary clan actually predates true mammals. The situation begs for more analysis, more fossils, or both, experts say.Vertebrate paleontologist Richard Cifelli, co-author of the Nature article analyzing the two claims said, “These new fossils change everything.” Arboroharamiya, a presumed tree-dwelling haramiyid said to have lived 160 million years ago, probably had a prehensile tail and possessed even longer digits than many tree-dwelling mammals today. It had well-adapted teeth, a modern-looking mammal jaw, and a modern mammal-like ear structure. Evolutionarily speaking, it implies that mammals originated long before previously expected—some 201-228 million years ago.Megaconus, a chipmunk-sized land dwelling haramiyid with preserved fur impressions, is thought to have lived 4-5 million years earlier, but its discoverers estimate the common ancestor of mammals lived 180 million years ago—tens of millions of years earlier than the other team’s estimate. Moreover, they think mammals branched away after Megaconus and other haramiyids, including Arboroharamiya, lived.Unfortunately, neither family tree is entirely consistent with all the data. Cifelli says that the confusion can be cleared up only with more fossils — preferably ones that include all or a significant part of a skull, whose anatomical features are particularly instructive in working out evolutionary relationships. “To break this tie, we really need more information,” he says.Is the taxonomy wrong? Is the phylogeny wrong? Are they really mammals? They had mammal like features, and Megaconus was found with clear fur impressions. Cifelli and Brian M. Davis say that 215 million years as the date of the mammal ancestor is “a much earlier date than many palaeontologists would accept” even if it is consistent with some molecular clock models. The controversy directly affects evolution:The evolutionary history of various mammalian groups has been characterized as ‘long fuse’, ‘short fuse’ and ‘explosive’, depending on the time elapsed between their origin and significant diversification. Zheng and colleagues’ tree, which places the origin of mammals at 40 million to 50 million years before their Jurassic radiation, implies a long-fuse model for the group as a whole… Zhou and colleagues’ competing hypothesis, on the other hand, is consistent with an explosive model… These alternative family trees and implied models of diversification have profound ramifications for interpreting the significance of key adaptations, ecological interactions and other events in the early history of mammals.Clearly, “explosive” models are distasteful for classical neo-Darwinians who believe in gradualism. But there’s another problem. No matter which view is accepted, both require believing in convergent evolution:Neither family tree perfectly explains all the data, of course. Indeed, each implies seemingly unlikely examples of independent evolution or reversal (homoplasy) of key characteristics. Zheng and colleagues’ model, for instance, suggests that the complex, three-boned middle ear, long regarded as a diagnostic feature of mammals, may have arisen independently at least three times — in the multituberculate–haramiyidan group, in monotremes (platypuses and echidnas) and in therians (marsupials and placentals). Similarly, the tree proposed by Zhou et al. requires independent evolution of strikingly similar tooth features — the presence of a single pair of enlarged, forward-facing incisors and complex cheek teeth with multiple rows of cusps, for example, that are presumably associated with herbivory — in haramiyidans and multituberculates.A good scientific theory would not wish to multiply miracles.Like the other article, this one by Cifelli and Davis ends with hope that more fossil finds will help. Zheng’s team agrees, though, that “Regardless of various phylogenetic scenarios involving allotherians, morphological convergences and/or reversals were common in the early stage of mammalian evolution.”These controversies were ignored by the news reports. Instead, they all included an artist’s rendition of Megaconus, snout, fur and all, even though the fossil did not include a skull. Science Now teased its readers with the title, “What Walked Like an Armadillo, Looked Like a Squirrel, and May Have Had Poison Spurs?”, never letting on about the controversies caused by this and the other fossil.Don’t you think the public should know? Do reporters think that people are too stupid to understand legitimate debates in science? Must interpretations from fallible scientists always be presented as facts of nature? Why must Charlie’s idol always be propped up to save his face from the evidence? Who can really believe that complex teeth or middle-ear bones evolved independently two or three times by unguided processes? Why must occult phenomena, like mythical common ancestors in ghost lineages, be invoked as if they had any real existence outside the imagination of Darwinians? Why must readers be told that evolutionary diversification is “explosive” in direct contradiction to a core tenet of Darwinism? Why must reporters always be sycophants and lackeys for the evolutionary scientists?The secular science sites—all of them—have bowed the knee to the Bearded Buddha, that’s why. Because CEH adheres to a different religion, one that cares about truth, we can read these papers with a critical eye and point out the fallacies and tricks of the Darwin Party’s religion. Their origins story has more holes than swiss cheese, more miracles than Greek mythology, more divination techniques than Babylonian religion. Call it what it is: a secular religion, invented out of distaste for the Biblical Creator. It’s full of imagination, storytelling and myths. Dressing it up in scientific jargon doesn’t sanctify it as science. Adding millions of years doesn’t make its miracles more plausible: miracles of well-adapted animals “arising” fully formed out of nowhere, miracles of “convergent evolution,” miracles of “explosive radiation.” Darwinian religion conjures up spirits, animals “trying out” unexplained and undocumented innovations, natural selection “tinkering” in Tinker Bell’s garage, a mystical life force pushing mindless particles toward the divine. The priests of Darwin waste their time trying to force uncooperative facts into their mythical “tree of life,” that after 154 years, still looks like a lawn. Who would believe this stuff? Ancient Egyptian religion looks more respectable than the Darwin cult; at least its gods and goddesses acted with purpose and intent.Don’t think for a minute that secular scientists abhor miracles and deny the supernatural. Everyone believes in miracles. Everyone who thinks believes in the supernatural (e.g., laws of logic not made of particles). Nothing comes from nothing. Choose a world view that has miracles that are intelligently designed. Choose a religion that explains with reference to true causes known to be necessary and sufficient for the complexity observed by honest scientific inquiry. Choose one that maintains human dignity and a love of the truth. Those criteria weed out a lot of contenders.(Visited 63 times, 1 visits today)FacebookTwitterPinterestSave分享0