Tuesday, October 13, 2015

Open Access- History Of Life Articles In Current Biology

Update: November 6 2015- The articles are no longer open access.

This is a treat!

A special section in Current Biology on the History of Life with short essays and longer reviews on a variety of evolutionary history topics. So far I have read four:

The Cambrian Explosion - Derek E.G. Briggs
The Neoproterozoic- Nicholas J Butterfield
Novelty and Innovation in The History Of Life- Douglas H Irwin
Life in the Aftermath of Mass Extinctions- Pincelli Hull

These are densely written and immensely informative articles about various aspects of the evolution of the earth and its biosphere.

Couple of passages-

..from Novelty and Innovation in The History Of Life on the different styles of diversification seen in the fossil record-

Several challenges have arisen to claims that adaptive radiations are responsible for most evolutionary diversifications. For one, many events have been identified among both living and fossil clades that cannot be explained as the outcome of diversification from a single species. Examples range from the Cambrian explosion of animals, which involved many major clades but relatively few species, to the diversification of grasses. I have already discussed cascading radiations where increased diversity was driven by ecological interactions between clades. Other diversifications, for example the spread of a genus across a continent, may be largely non-adaptive. The most striking observation, however, is the absence of evolutionary novelty associated with classic adaptive radiations. Indeed, by their nature, adaptive radiations concern the adaptive exploitation of ecological opportunities via variation on existing adaptive themes, but not the formation of the themes themselves. While the fossil record documents adaptive radiations that encompass greater morphological diversity than Darwin’s finches, mockingbirds or Anolis lizards, including the spread of insects and angiosperms, and the Mesozoic radiation of mammals, the origins of morphological novelties often seem to involve a different process.

..from The Aftermath of Mass Extinctions-

Macroevolution is shaped as much by those who survive as those who did not [3,121]; it is shaped as much by extinction, as by innovation and speciation [3,122]. More than 99% of all the species that have ever lived are now extinct [3], and the losses have often been distinctly non-random [7,8]. The largest biotic crises eliminate entire branches of the tree of life [1], drive the decline of once diverse clades [123], and lead to the radiation of new species and ecosystems [13,124,125]. In the prolonged aftermath, ecosystem change across the globe exerts an evolutionary influence distinct from the extinction itself, with a timing characteristic of the earth system (i.e., earth system succession). As such, mass extinctions should not be considered as macroevolutionary point events, but rather as prolonged intervals of varying selection spanning the mass death and subsequent radiation of taxa.

The last line adds some perspective.... that although mass extinctions are defined by death, there is also evolution, often at elevated rates, going on during this interval. Groups of organisms which are able to adjust and evolve their way through environmental crises will find and occupy emptied ecologic niches and so to speak inherit a new earth to settle and diversify.

As you would have guessed from the articles I first dived into, my interest lies primarily on the broad patterns of evolution as revealed from the fossil record. But there are plenty more biology oriented articles to capture your interest. 

Current Biology

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