Or so we learn from “It’s All in the Head: Songbirds With Bigger Brains Have Benefited from the End of Communism” (ScienceDaily Sep. 16, 2011):
End of communism favored birds with bigger brains
The scientists thus discovered that regional differences in population trends among songbird species are linked to their brain size. Large brain size was correlated to strong increases of respective songbird species in the Czech Republic since 1989 / 1990, weaker increases in Eastern Germany and had no effect in North-Western Germany. This difference between the former ‘West’ and ‘East’ suggests that this trend was driven by socio-economic changes that took place in the former communist regions. “Relative brain size reflects species’ cognitive abilities. The increase of such songbirds suggests that species with good cognitive abilities might have been better able to adapt to rapid socioeconomic change and make use of the novel opportunities that arose after the end of communism.” Dr. Katrin Boehning-Gaese, researcher at the Biodiversity and Climate Research Centre (BiK-F) and professor at Goethe-University, Frankfurt am Main, explains.
This story shows the perils of too great an emphasis on adaptationism (Darwinism) in assessing changes over time.
Communism was (and was meant to be) a huge and deadly upheaval in many parts of Europe, but wilier birds should have survived it better. Eliminating Communism produced a new upheaval, but usually in the direction of greater abundance, not less. Greater abundance means that survival requires less intelligence.
Clearly, there should be a better explanation for the predominance of large-brained species. Are more affluent people, newly equipped with bird feeding products, more likely to feed birds that are smart enough to notice them and respond? Worth considering.
But the cause could be something arcane that no one has considered – unrelated to selection, except in the sense that some got it and some didn’t.