In “Evolution Drives Many Plants and Animals to Be Bigger, Faster (ScienceDaily, Mar. 9, 2011), we learn:
For the vast majority of plants and animals, the ‘bigger is better’ view of evolution may not be far off the mark, says a new broad-scale study of natural selection. Organisms with bigger bodies or faster growth rates tend to live longer, mate more and produce more offspring, whether they are deer or damselflies, the authors report.
Researchers working at the National Evolutionary Synthesis Center compiled and reviewed nearly 150 published estimates of natural selection, representing more than 100 species of birds, lizards, snakes, insects and plants. The results confirm that for most plants and animals, larger body size and earlier seasonal timing — such as earlier breeding, blooming or hatching — confer significant survival advantages.
“It’s a very widespread pattern,” said co-author Joel Kingsolver of the University of North Carolina at Chapel Hill.
Hmmm. Various suggestions are offered, including
Another possibility is that environments simply change from one season to the next, such that the traits that confer the greatest advantage change over time. “In Darwin’s finches, for example, there are years where large-beaked birds have an advantage because large seeds are more abundant, and years where smaller-beaked birds do better because small seeds are more abundant,” Diamond said.
So, is it okay now to admit that Darwin’s finches are not evolving rapidly into new species, but rather one type or another is simply more likely to dominate, depending on the weather pattern?