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New Findings Supply Corrective to Evolutionary Hypothesis | University of Arkansas
In a highly mathematical, technical paper in PLOS Computational Biology, some of which is above my paygrade, two evolutionary biologists have shown that the mysterious apparent accelerations in the rate of evolution are actually due to statistical 'noise' and not a true change in the rate of evolution.
I've written this post about it not because it contains some interesting information about biological organisms or that long history of life on Earth that occurred before creationists believe their little god created a small, flat planet with a dome over it, but so creationists can see how badly they've been deceived by their cult leaders who have been telling them for the best part of half a century that mainstream biologists are about to abandon the Theory of Evolution any day now in favour of their childish superstition with its magical creation of species without ancestors.
Of course, to a simplistic, black vs white thinking creationist, any discovery that scientists might have been wrong about some precise detail or others can be presented as 'proof' that the entire body of science is wrong, but that's not how grown-up science works. To think otherwise is the equivalent of thinking having to detour round a parked car in a road means the satnav is broken.
Two computational biologists have recently published evidence that the appearance of accelerated rates of evolutionary change is due to statistical 'noise' in the data* What impact would this finding have on the basic principles of evolution? If the recent findings by computational biologists suggesting that accelerated rates of evolutionary change are largely due to statistical noise are accurate, this would have several important implications for the study of evolutionary biology. However, it is essential to clarify that these findings would likely not overturn the basic principles of evolution (such as natural selection, genetic drift, mutation, and gene flow), but they could impact how we interpret the tempo and mode of evolutionary change. Here are a few possible impacts:The truth is that biologists have no doubt about the basic principle of evolutionary diversification from a common ancestor, driven by environmental selectors; their debate is only over the details of the processes and how they relate to environmental changes.
- Reevaluation of Evolutionary Rates
- One key implication would be that observed patterns of rapid evolutionary change (in specific lineages or over short time periods) might need to be reinterpreted. If statistical noise has exaggerated the perception of these rates, what may have seemed like "punctuated bursts" of rapid evolution could, in fact, represent more gradual processes.
- Some models of evolution, such as punctuated equilibrium (which argues that species experience long periods of stasis interrupted by short, rapid bursts of change), might need reconsideration. While this does not disprove punctuated equilibrium, it could require revisiting the evidence used to support it.
- Statistical Models in Evolutionary Biology
- The study would emphasize the importance of statistical rigor in evolutionary studies. Researchers would need to account for and reduce noise in their data more carefully to avoid overestimating rates of evolution.
- This might lead to more robust methods for analyzing phylogenies, genomic sequences, and fossil data to ensure that we distinguish genuine signals of evolutionary change from artifacts produced by incomplete data or noisy statistical models.
- Impact on Molecular Evolution Studies
- Much of the evidence for accelerated evolution, especially at the molecular level, comes from comparative genomics, which measures changes in DNA sequences over time. If noise in the data has been overestimating these rates, it would affect interpretations of molecular clocks, the timing of divergence events, and the rates of adaptive evolution.
- This could also alter our understanding of when certain key evolutionary transitions took place, such as the divergence between major groups (e.g., between humans and chimpanzees) or the timing of the origin of new traits.
- Evolutionary Innovation and Adaptation
- If rapid changes are less common than previously thought, this could affect theories about the mechanisms underlying evolutionary innovation. For example, the appearance of new traits or adaptations may occur more slowly than we assumed, and might more often involve cumulative changes rather than rapid shifts.
- This might challenge the idea that certain environmental pressures (e.g., mass extinctions or rapid climate change) consistently trigger bursts of rapid adaptation.
- Reevaluation of Case Studies
- Many well-known examples of rapid evolution (e.g., the finches of the Galápagos, the peppered moth) might need closer scrutiny to ensure that the rates of change observed in these cases are genuine and not artifacts of noisy data.
- Fossil and genomic data used to reconstruct evolutionary timelines might also need reevaluation in light of these findings, with the possibility that some inferred rates of change may need adjustment.
- Broader Implications for Evolutionary Theory
- The fundamental concepts of evolution—such as descent with modification, natural selection, and common ancestry—would remain intact, as these are supported by a vast range of evidence beyond the statistical models of evolutionary rates. However, the findings could influence the details of how we model evolutionary dynamics, especially over short timescales or within particular lineages.
- The study could lead to a greater emphasis on distinguishing between "real" evolutionary signals and those that result from data imperfections, potentially improving the accuracy of evolutionary research going forward.
In summary, the basic principles of evolution are robust and unlikely to be overturned by this finding. However, it could lead to more refined methods in evolutionary biology, impacting how we interpret rates of change and the timing of evolutionary events, potentially leading to more accurate evolutionary histories.
The scientists' work is explained in a University of Arkansas news release: