My comment on: Rapid morphological evolution in the Silvereye: random processes or selection?
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Much of this is over my head, so I'm probably not appreciating the gist of the study. Just finished reading/skimming the paper. I wish that there had been some, or any, discussion of the rather significant difference in climate between Tahiti and New Zealand.
Here in the Los Angeles area my friend and I often share plants with each other. She lives closer to the coast than I do so her conditions are more intermediate than mine. For a while now I've been wanting to try conducting a simple experiment to quantify the variation in temperature preference in a batch of seeds. We'd sow the seeds from a single pod of say Begonia fischeri (the only "weedy" Begonia here) and then split the pots. When the seedlings were a few inches tall we'd share half of the largest ones with each other. So we'd each have two batches of seedlings. Then we would compare the disparity in blooming time. The greater the disparity, the greater the variation in temperature preference, the more adaptable the species.
If you took a dozen Silvereyes from Tahiti, a dozen from New Zealand, and introduced them to two different islands in say Hawaii, we can reasonably guess that the Tahiti ones would colonize their island faster. How much faster though? The disparity would quantify the adaptability of this species. The disparity would be even greater if it was 100 rather than 12 birds initially introduced. What about if a third island was colonized with a 100 crosses between the two populations? They'd fall somewhere in the middle? Or perhaps they would win as a result of greater variation in other factors such as body/brain/beak/wing size?
Right now there's discussion, or maybe even efforts, to eradicate hybrids between native iguanas and invasive ones. The goal is ostensibly to prevent the loss of diversity. But I think the scientists are somehow missing that the very point of diversity is adaptability. It's entirely possible that the hybrids will be better than the parents at adapting to rapid climate change. Perhaps our own very existence is due to greater climate adaptability conferred by our ancestors mixing with more cold tolerant neanderthals.
