Revista Chilena de Historia Natural 83 (4): 479-495, 2010
Is the evolutionary theory still useful? A review with examples
Evolutionary biology is experiencing an exceptional process of revision and outreach
because of the 200-anniversary if the birth of Charles Darwin. As a consequence, the study of organic evolution and also its teaching
are being discussed at several levels, by evolutionary biologists, biologists and scholars outside evolutionary biology and by the general
public. In this scenario, a didactic explanation of how biologists address evolutionary research in real populations seems to be useful.
Using actual research examples, here I tried to outline how the classic theory (termed here as the “basic scheme”) is useful to answer
relevant questions in biology and how a less dogmatic paradigm (or a more versatile one) would be needed when dealing with the most
recent and extravagant cases of gene, genotype, phenotype and environment interactions. Specifically, I used three in-extenso
examples of research driven by hypothesis-testing: (1) the changes in genetic architecture induced by sexuality in a cyclically
parthenogenetic insect; (2) the test of the energetic definition of fitness through phenotypic selection studies; and (3) the assessment
of the underlying causes of character displacement in Darwin finches. In the former two cases, it is argued that the basic scheme is
useful and sufficient for testing relevant evolutionary hypotheses. In the third case, it is argued that something else is needed to explain
the observed genetic variation that Geospiza species exhibit in Daphne major island (Galapagos). Finally, I outline some
“extravagant” cases biological entities interacting, such as horizontal gene transfer, epigenetic inheritance, adaptive anticipatory
conditioning, evolutionary capacitance and niche construction. This “post- modern” biology has been seriously proposed and
demonstrated to be widespread in nature, which would justify an extended evolutionary synthesis.
Key words:
character
displacement, microevolution, modern synthesis, natural selection, population genetics
