Backtracking on Darwinian Claims
Evolutionary theory evolves. Since Darwinists no longer consider evolution progressive, it follows that evolutionary theory is also not necessarily progressing. The following stories show evolutionary biologists backtracking on earlier claims.
- The pig is falling. “Darwinian evolutionary theory proposes that the phenotype of a creature is an adaptation to the particular demands of the ecological situation in which it evolved,” wrote Geraint Rees [University College, London] in Current Biology.1 That’s what he intended to show in a report on a study suggesting humans are attracted more to animal motion than inanimate motion.2 He had to acknowledge, however, that a completely different, non-Darwinian interpretation is possible. This led to him joking about why pigs don’t have wings:
This suggests that the ability to detect change in animate objects represents a heritable trait that reflects implicit information about the external structure of the environment in which humans evolved, an intriguing possibility. But while intuitively appealing, caution is required before accepting such an argument. Jerry Fodor has recently argued that phenotypes do not always represent implicit information about the environment in which they evolved. Instead, sometimes phenotypes simply reflect internal constraints on the functional organisation of that animal. For example, Fodor suggests that the reason pigs do not have wings is less to do with the intrinsic structure of the environment that pigs inhabit, and more to do with the fundamentals of how the pig is constructed. The lack of wings does not by itself carry any intrinsic information about the pig’s natural environment, and has not been selected against in the course of porcine history!
In that case, there is no information about pig or human evolution to be gained from the study at all. The findings about human propensity to pay attention to animal motion, instead, “provide important insights into the organisation of the human visual system,” he said, though he still held out hope that adding natural selection to the equation might inform the “discovery of the psychological architecture of human cognition.”
- Platypus granddaddy: News@Nature examined the case of the ancient platypus (see 11/27/2007). The bones of an apparent platypus 20 to 80 million years older than thought is causing confusion among evolutionary paleontologists. Timothy Rowe, the discoverer, concluded “It looks like the monotremes may have had a really slow evolutionary history.” Why the vast array of mammals underwent dramatic transformations in far less time, according to the Darwinian timeline, leaves a mystery why the platypus remained virtually unchanged. “Rowe thinks the creatures probably didn’t need to evolve because their hunting abilities were so fine-tuned,” the report said. This begs the question of why other predators with similarly fine-tuned hunting skills lack the evolutionary stasis, or why the platypus’s prey did not evolve so as not to be hunted so effectively.
The contrary explanation, that this was not a platypus fossil at all, but rather a remnant of a common ancestor of platypus and echidna, requires invoking convergent evolution. A platypus-specific canal found in the skull would have had to evolve twice, once before the split, and once again after the split. The illustration caption simply reads, “Older than we thought.”
The paper by Timothy Rowe et al in PNAS3 states the conundrum in scientific jargon:
Morphology suggests that Teinolophos is a platypus in both phylogenetic and ecological aspects, and tends to contradict the popular view of rapid Cenozoic monotreme diversification. Whereas the monotreme fossil record is still sparse and open to interpretation, the new data are consistent with much slower ecological, morphological, and taxonomic diversification rates for monotremes than in their sister taxon, the therian mammals. This alternative view of a deep geological history for monotremes suggests that rate heterogeneities may have affected mammalian evolution in such a way as to defeat strict molecular clock models and to challenge even relaxed molecular clock models when applied to mammalian history at a deep temporal scale.
- Predators and unintended consequences: The simple view is that predators kill prey, leading to prey that try to reproduce faster in greater numbers – a direct effect of evolutionary ecology. A study with small fish called killifish that inhabit streams in Trinidad showed scientists a more complex view. In addition to direct effects of predation, there are indirect effects that may be just as important: for instance, the availability of food after prey are reduced by the predators. The whole community is restructured by reintroduction of predators. “Since predator-induced indirect increases in resource availability are common in both terrestrial and aquatic ecosystems, the evolutionary consequences of these interactions are potentially a very important component of evolutionary change in nature,” said David Reznick, coauthor of the study. “Moreover, biologists have observed evolutionary change occurring on short ecological timescales in nature, on the order of a few years to decades, suggesting that such interactions are contributing to overall ecosystem functioning and health.” The changes he described, however, are microevolutionary changes to existing structures, not innovations. If microevolutionary restructuring of ecological communities can be witnessed in mere decades, it adds to the conundrum of why the platypus remained unevolved for 100 million years.
- Black sheep in Darwin’s family: Fitness is supposed to help you gain the upper hand in the race to survive, but the fitter black sheep of Scotland are dying out. Why? A study in Science4 found that fitness can work against you. Dark coat color is correlated to larger body size, “which is heritable and positively correlated with fitness,” the research team said. “This unexpected microevolutionary trend is explained by genetic linkage between the causal mutation underlying the color polymorphism and quantitative trait loci with antagonistic effects on size and fitness.” The finding makes evolutionary inference more difficult. “This result demonstrates the importance of understanding the genetic basis of fitness variation when making predictions about the microevolutionary consequences of selection.” The article began, “The evolutionary changes that occur over a small number of generations in natural populations often run counter to what is expected on the basis of the heritability of traits and the selective forces acting upon them.” When a scientist can’t expect what evolution will do, can Darwin really claim to have discovered a law of nature?
- Papa Neanderthal: It seems the story of our relationship to Neanderthal Man is back and forth. An article in the Australian News explains the problem: “For more than 150 years, a debate has raged over the origins of modern humans. The main body of scientific thought says modern humans migrated from Africa and then overwhelmed their more primitive European counterparts, the heavy-browed Neanderthals, or inter-bred with them. But growing credence is being given to the theory that homo sapiens [sic] evolved from the Neanderthals, who mysteriously died out some 28,000 years ago.” So no one seems to know what the relationship was. That did not stop the author from titling the report, “Bad weather helped evolution.”
- Tree trimming: Darwin’s tree of life just lost a branch. “The Tree of Life must be re-drawn, textbooks need to be changed, and the discovery may also have significant impact on the development of medicines,“ began an article in Science Daily. New research by European biologists who compared 5000 genes in “the largest ever genetic comparison of higher life forms on the planet” now lumps brown algae and silica algae together. “Previously, these species were thought to be completely unrelated,” the article states. The article ended on a triumphal note that researchers are making progress toward understanding evolution. Puzzles remain, however: “To make the picture a little less clear, one branch of chromalveolates is still in no man’s land,” claimed one researcher.
- Mammal disconnect: The molecular and fossil stories about mammals don’t agree; see Geotimes for discussion. Watch this space. (That’s all there is to watch for now.)
- More than a chimp: Be thankful for your DNA repair genes; they are unique. An article in EurekAlert said, “researchers were surprised to find the acquisition of functional response for certain genes involved in DNA metabolism or repair to be mostly unique in humans.” Some of the genes were shared with chimpanzees and rhesus monkeys; none were shared with mice. The researchers wove their findings into an evolutionary story, but admitted, “the full implications of these evolutionary points remain far from clear….”
- The new buzz: Remember the old story? The one about the meteorites that killed the dinosaurs? Scratch that. It was bugs. The new story can be found at The Guardian, which says, “Forget the meteorites – it was insects that did in the dinosaurs.” This can be considered true till the next revision. Hold the presses! Maybe it was acid rain, reported EurekAlert. But then again, that old Chicxulub meteor did make a mighty big splash, say the Longhorns.
1. Geraint Rees, “Vision: The Evolution of Change Detection,” Current Biology, Volume 18, Issue 1, 8 January 2008, Pages R40-R42.
2. For a similar claim by others, see the 01/07/2008 entry.
3. Rowe et al, “The oldest platypus and its bearing on divergence timing of the platypus and echidna clades,” Proceedings of the National Academy of Sciences USA, published online before print January 23, 2008, 10.1073/pnas.0706385105.
4. Gratten et al, “A Localized Negative Genetic Correlation Constrains Microevolution of Coat Color in Wild Sheep,” Science, 18 January 2008: Vol. 319. no. 5861, pp. 318-320, DOI: 10.1126/science.1151182.
Translating Timothy Rowe’s jargon into colloquial English (blue quote in bullet #2 above), he said, “We’ll, I’ll be. Shore looks like a platypus. How come all its brethren evolved all over the place while he just sat there? Musta been stuck in a Darwinian rut somehow. Better tell my geneticist buddies their clocks are runnin’ super-fast and super-slow all at once. The clocks musta e’en forced this little guy to evolve in slo-mo! Whatever. We KNOW dem bones is 120 million years old – that’s a fact, even if the clock is outta whack.”
Darwinism is the perfect playground for science fiction writers (that is, evolutionary biologists). You never have to be right; you just have to look busy. You can tell creative stories, then celebrate when they are overturned later. The more complex the plot, the better. You have no threat of criticism because your critics have been expelled and put behind a sound-proof barrier. You get free checking for making reckless drafts on the bank of time (07/02/2007). The peasants don’t revolt, because they have been hypnotized into thinking what you are working on is science. Ah, the life of a Chaldean soothsayer. It was bliss before Daniel showed up.