In new species emergence and diversity, according to From ScienceDaily:
For the massive meta-study effort, researchers painstakingly assembled data from 2,274 molecular studies, with 96 percent published in the last decade. They built new computer algorithms and tools to synthesize this largest collection of evolutionary peer-reviewed species diversity timelines published to date to produce this Time Tree of Life.
The study also challenges the conventional view of adaptation being the principal force driving species diversification, but rather, underscores the importance of random genetic events and geographic isolation in speciation, taking about 2 million years on average for a new species to emerge onto the scene.
“This finding shows that speciation is more clock-like than people have thought,” said Hedges. “Taken together, this indicates that speciation and diversification are separate processes from adaptation, responding more to isolation and time. Adaptation is definitely occurring, so this does not disagree with Darwinism. But it goes against the popular idea that adaptation drives speciation, and against the related concept of punctuated equilibrium which associates adaptive change with speciation.”
Besides the new evolutionary insights gained in this study, their Timetree of Life will provide opportunities for researchers to make other discoveries across disciplines, wherever an evolutionary perspective is needed, including, for example, studies of disease and medicine, and the effect of climate change on future species diversity.
Well, if adaptation does not drive speciation, then surely the model does disagree with Darwinism* (natural selection acting on random mutation – as in “random genetic events”?).
Anyway, if speciation is really clock-like, would not either an undiscovered law or a design be at work?
It sounds like these people want to jump over the wall, but don’t want to face the bullets from the guards’ turret.
Genomic data are rapidly resolving the tree of living species calibrated to time, the timetree of life, which will provide a framework for research in diverse fields of science. Previous analyses of taxonomically restricted timetrees have found a decline in the rate of diversification in many groups of organisms, often attributed to ecological interactions among species. Here we have synthesized a global timetree of life from 2,274 studies representing 50,632 species and examined the pattern and rate of diversification as well as the timing of speciation. We found that species diversity has been mostly expanding overall and in many smaller groups of species, and that the rate of diversification in eukaryotes has been mostly constant. We also identified, and avoided, potential biases that may have influenced previous analyses of diversification including low levels of taxon sampling, small clade size, and the inclusion of stem branches in clade analyses. We found consistency in time-to-speciation among plants and animals—approximately two million years—as measured by intervals of crown and stem species times. Together, this clock-like change at different levels suggests that speciation and diversification are processes dominated by random events and that adaptive change is largely a separate process. – S. Blair Hedges, Julie Marin, Michael Suleski, Madeline Paymer, and Sudhir Kumar. Tree of life reveals clock-like speciation and diversification. Molecular Biology and Evolution, 2015 DOI: 10.1093/molbev/msv037 Here’s the pdf
* Be it noted that the phrase the researchers use is Darwinism (some claim the term is no longer in use, but that is not our etymological experience).
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