Macroevolução: a dinâmica da diversidade

quarta-feira, janeiro 18, 2012

Current Biology, Volume 21, Issue 24, R1000-R1001, 20 December 2011

Copyright © 2011 Elsevier Ltd All rights reserved.

10.1016/j.cub.2011.11.007

Macroevolution: Dynamics of Diversity 

Authors

Douglas H. Erwin

Summary

The fossil record typically exhibits very dynamic patterns of innovation, diversification and extinction. In contrast, molecular phylogenies suggest smoother patterns of evolutionary change. Several new studies reconcile this difference and reveal more about the mechanisms behind macroevolutionary change.

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NOTA DESTE BLOGGER:



Erwin tenta resolver a “tension between microevolutionists and macroevolutionists” [tensão entre os microevolucionistas e macroevolucionistas]. Uma tensão que perdura há muito tempo em ciência.

Cientistas que defendem o microevolucionismo podem lidar com este aspecto nos laboratórios (como revelam 99.99% das pesquisas e artigos publicados demonstrando o fato, Fato, FATO da evolução. 

Os cientistas que defendem o macroevolucionismo procuram essas provas nos fósseis. 

Erwin afirma que “Several recent papers now shed new light on macroevolutionary processes” [Diversos artigos recentes lançaram nova luz sobre os processos macroevolucionários].


Então, quais são as trevas epistêmicas nas quais nós nos encontramos? Erwin nos conduz pelo caminho:

The discrepancy between plots of the diversity of taxa through time as inferred from molecular phylogenies and those based on counts documented by the fossil record has long been troubling, largely because molecular phylogenies appear to underestimate the frequency of extinction.” 

“Punctuations Are Not Passé.”

“Their analysis supports a model of rare bursts of extensive evolutionary change in a sea of shorter-term fluctuations.”

"The bursts of evolutionary change over longer timescales remain to be explained but could reflect episodic changes in the optimal adaptive phenotype as the environment changes, as the authors suggest, the construction of new ecological environments, or the longer waiting time for significant developmental innovations."

"In each of these papers [2,3,4] the results document a greater range of evolutionary processes, including great differences in origin and extinction rates in different clades through time, bursts of phenotypic change interrupting intervals of greater phenotypic quiescence, and a structuring of the developmental sources of evolutionary change".

Será que finalmente o fato, Fato, FATO da tensão entre a microevolução e a macroevolução foi realmente resolvido   nessas pesquisas mencionadas por Erwin?

Eu continuo cético.