The Why and How of Leopard Spots
51; A leopard may not be able to change its spots (Jeremiah 13:23), but maybe evolution can – if evolutionists – or Rudyard Kipling – can tell us how or why. A headline in the BBC News promised to tell us “how the leopard got its spots,” while PhysOrg promised to reveal, “Why the leopard got its spots.” Neither did either; neither a rule nor a mechanism was found.
The inspiration for a study of cat fur markings was Rudyard Kipling’s Just-So Story, How the leopard got his spots. According to the BBC story, researchers at the University of Bristol subtitled their paper in the Royal Society Proceedings B, “Why the leopard got its spots.” They came up with a mathematical model relating species to habitat for 37 species of wild cats. Kipling’s story, they concluded, was only half right; cats needed to camouflage themselves in the forest, but the mechanism that he said produced them (an Ethiopian imprinting them with his fingers) was a childish tale. Unfortunately, their explanation didn’t provide much more insight, because their rule that “cats living in the trees and active at low light levels are the most likely to have complex and irregular patterns” has notable exceptions, leaving them puzzled why tigers have stripes but lions don’t, and why cheetahs have spots but don’t live in the forest.
William Allen [U of Bristol] attempted to explain the data: “The pattern depends on the habitat and also on how the species uses its habitat – if it uses it at night time or if it lives in the trees rather than on the ground, the pattern is especially irregularly spotted or complexly spotted.” But the BBC had to admit he only found some rough correlations: “Dr Allen’s study still fails to explain the mechanism of wild cats’ pattern development – but the scientists managed to find a set of numbers to measure the irregularity or complexity of a pattern and correlate this with where the species lives to explain its behaviour.” Why, though, does patterning emerge and disappear “very frequently” within the cat family? Allen said, “particular genetic mechanisms can solve very different appearances of cats,” but how? What are these genetic mechanisms? Genes can’t see the forest. If evolution selects out of existence those without lucky patterns that provide camouflage, why are the results inconsistent?
Other explanations for cat markings have fallen into disfavor. The patterns don’t seem to be for sexual display or for social signals. But the new study has its problems: “Although a clear link between environment and patterning was established, the study also highlighted some anomalies,” the PhysOrg article said. “For example, cheetahs have evolved or retained spotted patterns despite a strong preference for open habitats, while a number of cats, such as the bay cat and the flat-headed cat, have plain coats despite a preference for closed environments. Why this should be remains unclear,” he said – so unclear, in fact, that the evolutionary explanation seems unable to distinguish whether the cheetah “evolved” the spots or “retained” them. The former notion would make the explanation circular; the latter, contrary to the expectations of natural selection. So despite Allen’s claim that “The method we have developed offers insights into cat patterning at many levels of explanation,” it seems that evolution has done little to explain how or why the leopard got its spots.
Cataloguing and describing cat patterns is one part of science, but explaining a phenomenon is another, often harder, exercise. Scientists don’t want to just do stamp collecting. They want to offer insight. (Note that finding correlations is not the same as explaining the relations). Darwin came along and thought he could shed light on the living world. Natural selection was a law-like mechanism that could account for all the diverse designs of life. If he had found a law of nature, we would see consistency in results, but we don’t. Neo-Darwinism hasn’t provided any more insight. It just re-packaged the old darkness. What lucky mutation occurred in what gene? How did it correlate with the environment? Was it really adaptive? (see 10/19/2010). If natural selection can explain opposite results, it explains nothing at all. What did he improve on, really, more than John Ray and Linnaeus, who saw God’s design in the adaptive patterns in living things?
Evolutionists like to look busy: doing field work, whipping out their math tools, publishing papers. Their answers of how and why become as elusive as a stealthy leopard in the jungle. When all is said and done, evolutionary explanations amount to little more than just-so stories. What Kipling’s story lacks in insight it makes up for in entertainment. Given that insight is comparably lacking in Allen’s paper, full as it is of dry math without justification, which would you prefer reading?
Exercise: Go to a zoo and admire the intricate patterns on animal fur – tigers, zebras, giraffes, pandas, leopards, chipmunks, ringtail cats, and more. Consider the remarkable adaptation of each animal to its ecological niche. Don’t ignore the ones with plain fur – the black panthers, prairie dogs, and bears. Read the evolutionary explanations and ponder whether adaptation implies evolution (see next headline), or whether evolution is merely a narrative gloss applied in retrospect to a dazzling array of diverse phenomena. In what cases is microevolution (sorting of pre-existing genetic information) adequate to explain adaptation as opposed to macroevolution (common ancestry with increase of genetic information)? Does the former imply the latter? (see extrapolation). How do genes without eyes on the environment get translated into precise geometric patterns in fur on the outside? Look at your dog or cat while you think on these questions.