(Visited 35 times, 1 visits today)FacebookTwitterPinterestSave分享0 Scientists find many examples of biological change that do not fit the mutation-selection paradigm.Change by losing genes (PhysOrg): Spanish researchers are puzzling over an “evolutionary paradox” involving the loss of genetic information. In order to rescue Darwin, they call it “losing to win” and another “engine of evolution.” But clearly microbe-to-man evolutionary progress requires the addition of huge amounts of information, not its loss.Thinking of gene loss as an evolutionary force is a counterintuitive idea, for it is easier to think that only when we gain something—genes in this case—can we evolve. However, the new work by these authors, who are members of the Research Group on Evolution and Development (EVO-DEVO) of the UB, characterizes gene loss as a great potential process of genetic change and evolutionary adaption [sic].A strange one, this “evolutionary force” is: perhaps it’s like a great sucking sound.Speciation by education: Science Daily announces that “desert elephants pass on knowledge — not mutations — to survive.” Researchers at the University of Illinois were surprised to find that Namibian desert elephants share the same DNA as African savannah elephants, despite differences in appearance and behavior that might cause some to classify them as different species. Apparently the animals pass on their knowledge by example; no mutations or selection required.“Our results and the historical record suggest that a high learning capacity and long distance migrations enabled Namibian elephants to shift their ranges to survive against high variability in climate and in hunting pressure,” said first author Yasuko Ishida, a research scientist in animal sciences at Illinois.Tricks with light in peacock spiders (National Geographic): Peacock spiders are among the most fascinating recent discoveries in arthropods. With fantastically-colored rear shields adorned in amazing patterns, the tiny but charismatic fast-dancing males try to attract the females with their charms and colors without getting eaten (watch examples on YouTube). This article explains that the red colors come from pigments, but the vivid blues come from geometric nanostructures that intensify certain wavelengths of light. While offering to explain how they got this way, the author says nothing about mutations or selection. Maybe that’s because it looks so teleological:“We’ve known for some time that butterflies and moths are doing all sorts of really clever things with manipulating the behavior of light with their scales,” says Nathan Morehouse of the University of Pittsburgh.“What we’re discovering with this study and others is that spiders—which are obviously a very different group of animals—are also playing with light.”Are they doing it on purpose? That would be very non-Darwinian. To add to the mystery, the article says that scientists are not even sure the female can see all the colors (although they probably do). Assuming they do, the male would have to “play with light” at the same time the female came up with a way to see the colors. Most spiders “aren’t really known for having fantastic color vision,” the article says, referring to another conundrum: the mystery of the blue tarantulas. “Science still can’t explain why these tarantulas are blue,” Nadia Drake wrote for National Geographic last year; “The spiders’ brilliant colors are the work of a still-mysterious evolutionary force.” A mysterious force could be a farce.Irrelevant selection (PNAS): This quote from a recent paper on the evolution of body form raises questions about whether evolutionists can detect what traits have supposedly evolved by natural selection and which have not. For instance, limb length cannot be selected for independently without affecting a multitude of other traits. If the evidence is distorted, how can anyone know that directional selection was responsible at all?Although most traits appear to be under directional selection, their response is constrained by between-trait covariance. This finding suggests that trait differences among human groups may not directly reflect the forces of selection that shaped them. Negative natural selection? To explain counterintuitive results by Beauchamp et al. about whether humans are still evolving, three evolutionists publishing in PNAS went on a fishing expedition to explain the observations, within a Darwinian context, that higher education is producing fewer children. Their answers, under “When genes and environment disagree: Making sense of trends in recent human evolution” call on “negative natural selection” and other tricks to explain the data. One can read the open-access paper to decide if they succeed, when they have to acknowledge that connections between genes and phenotypes are weak, connections between environmental pressures are complex, social factors can override selection, and measurements are hard to make. On New Scientist, John Hawks puts on an Olympic performance to keep the data within the Darwin arena.Rule-breaker ecosystems (Science Daily): The following quote should give a reality check to anyone who thought Darwinian evolution explains ecosystems. Speaking of South American forests, Carnegie’s Greg Asner remarks,“We found that Andean and Amazonian forests have evolved into diverse communities that break simple ecological ‘rules’ previously developed through field-based studies. These forests are actually much more interesting and functionally diverse than previously thought, and have sorted themselves out across a variety of environmental templates like geology, elevation and temperature,” Asner added.It turns out the forests aren’t so simply split between high-rollers and prudent investors either. Rather the authors found a continuum of forest canopy nitrogen, phosphorus, and leaf mass relationships that are sensitive to the enormous range of geophysical conditions found throughout the region.Dark skin is the default (PhysOrg): Here’s another evolution-by-loss story. Had you been taught that Africans evolved dark skin to avoid cancer, and Europeans evolved light skin to absorb more Vitamin D where sunlight was less intense? A new paper challenges these popular hypotheses about skin color, saying they have flaws that don’t make sense in evolutionary theory.For example, the peak incidence of the most common form of fatal skin cancer occurs above the age of 70. Because ancestral humans did not live nearly that long, and because this age is well after peak reproductive years in any case, the authors argue that natural selection is unlikely to have favored the stronger cancer protection afforded by dark skin. Although folic acid is critical for normal development, Elias said, the type of UV rays that destroy this nutrient rarely penetrate the skin down to the blood vessels where it resides. Moreover, the incidence of significant congenital malformations from folic acid deficiency is low, and unlikely to have influenced natural selection for additional pigmentation.Scrambling for a story to keep natural selection in the running, the scientists now think that dark skin provides “a more efficient permeability barrier, more cohesive and mechanical strength, and superior antimicrobial defense” than light skin. But since it is more costly to produce, Europeans who did not need these features lost it. Maybe it’s a process like cave fish losing their eyes.Such a worm as I (PhysOrg): Why should humans share traits with worms? Alongside a photo of a flatworm, this article alleges that “Stem cells of worms and humans more similar than expected” in terms of introns and alternative splicing mechanisms. Evolutionists come up with clever comebacks when confronted with anomalies like this. “For the first time, we described mechanisms in stem cells in organisms from extremely distant branches of the evolutionary tree,” they say, simply affirming their belief without explaining the observations.Altruistic whales (PhysOrg): It’s no longer anecdotal. Reports that humpback whales shield other animals from killer whales has photographic and eyewitness evidence, showing it to be a common behavior. The whales will even grasp seals in their flippers to save them from orcas. That presents an evolutionary conundrum; what does a whale have to gain by protecting another species? National Geographic stepped up to explain this in its “Weird and Wild” feature. “What is going on here?” reporter Jason Bittel asks. Perhaps this; perhaps that. Darwinian explanations require the organism to act in its own self-interest. That doesn’t seem to be happening in this case. Maybe it’s an amazing example of altruism in the animal world, he suggests, revealing that animals can really care for others.Whether humpbacks are truly performing what amounts to a good deed or are benefiting from the process, it’s clear that we still have much to learn about the minds and motivations of the animals around us.Live Science considers whether the altruism is intentional or unintentional, resorting to various stories about why self-interest might produce this behavior. Mindy Weisgerber tries to minimize the question: “There is indeed a great deal yet to be learned about the motivations of these hero humpbacks, but is the idea of animal altruism really so unusual?” she asks. Yes it is; that’s why Darwinians have struggled to explain it ever since Darwin (e.g. 2/08/15, 1/18/15). Bittel never did give an evolutionary explanation.Oh deer DNA (PhysOrg): Studies of DNA among various species of deer (cervids) produced a conundrum; the genes don’t fit the family tree, even though some species look alike. Incidentally, the following quote reinforces the fact that DNA degrades quickly (compare entry from 8/04/16):“Molecular data were already available for 46 of the 55 living cervid species ,” says Heckeberg. “Our aim was to complement this dataset and place the newly sequenced species in the cervid family tree.” Since the species involved are already rare and difficult to sample in the wild, the researchers resorted to material from a total of 13 museum specimens – and extracted DNA from samples of bone, skin and the dried remains of soft tissues. Some of these specimens were more than 100 years old and thus, the DNA was degraded. Nevertheless, the researchers succeeded in sequencing fragments of this ancient DNA corresponding to part of the genome of the mitochondria (the organelles responsible for the synthesis of ATP, which powers chemical reactions in nucleated cells).Since the genotypes and phenotypes didn’t match in several cases, the authors resorted to “convergent evolution” to keep the data within the neo-Darwinian paradigm: “Thus, the morphological similarities that led to their classification into the same clade are not the result of descending from a common ancestor, but reflect adaptations to related environments (convergent evolution).”Back to the drawing board for macroevolutionary inferences (PNAS): Bad news for neo-Darwinians. A common Bayesian technique for inferring macroevolutionary trends has gone BAMM!Bayesian analysis of macroevolutionary mixtures (BAMM) has recently taken the study of lineage diversification by storm. BAMM estimates the diversification-rate parameters (speciation and extinction) for every branch of a study phylogeny and infers the number and location of diversification-rate shifts across branches of a tree. Our evaluation of BAMM reveals two major theoretical errors: (i) the likelihood function (which estimates the model parameters from the data) is incorrect, and (ii) the compound Poisson process prior model (which describes the prior distribution of diversification-rate shifts across branches) is incoherent. Using simulation, we demonstrate that these theoretical issues cause statistical pathologies; posterior estimates of the number of diversification-rate shifts are strongly influenced by the assumed prior, and estimates of diversification-rate parameters are unreliable. Moreover, the inability to correctly compute the likelihood or to correctly specify the prior for rate-variable trees precludes the use of Bayesian approaches for testing hypotheses regarding the number and location of diversification-rate shifts using BAMM.This is significant, they say, because “Exposing the problems with BAMM is important both to empiricists (to avoid making unreliable inferences using this method) and to theoreticians (to focus their efforts on solving the problems that we identify).” The flaws are general to any evolutionary analysis of any part of Darwin’s assumed tree of life. “We have shown that these theoretical issues cause inferences using BAMM to be unreliable,” they conclude. Attempting to be charitable, they say, “We are hopeful that a reliable, model-based, Bayesian approach for detecting diversification-rate shifts can eventually be developed, but this remains a difficult and unsolved problem.” The paper is open-access for those wishing to explore the details and implications.Was there ever a more potent example of the power of the paradigm? Like Thomas Kuhn argued, normal science consists of researchers within a guild solving problems according to the rules of the guild, asking the questions the guild says are important, and using the tools the guild provides. Anomalies accumulate, but they are interpreted within the paradigm, as the “convergent evolution” example illustrates: “Houston, we have a problem; hand me the convergence wrench.”These news articles indicate that reality doesn’t fit the Darwinian cave. Those inside the cave are too focused on the shadows on the wall inside their box to turn around and look at the source of the light. It’s time for a scientific revolution; turn their butts around.Recommended resource: Check out Douglas Axe’s new book, Undeniable: How Biology Confirms Our Intuition that Life Is Designed.