Category: Climate change

Our title is evolutionary geneticist Arthur Weis to journalist Carl Zimmer on the topic of an experiment he and colleagues at UC Irvine carried out a few years ago where they compared those seeds — that had been “lying around” in the intervening few years in a cool, dry place — with seeds of the same species newly collected from the same sites. The result of the experiment was that…

…[t]he newer plants grew to smaller sizes, produced fewer flowers, and, most dramatically, produced those flowers eight days earlier in the spring. The changing climate had, in other words, driven the field mustard plants to evolve over just a few years.

The point of Zimmer’s article is that evolution can take place over short periods of time, and that because of climate change “life will undergo an evolutionary explosion.” ((We’ve blogged about this before.)) What Zimmer doesn’t say is that we have about 6.5 million similar samples of seeds in the world’s crop genebanks, and not by serendipity. Some date back decades. There would be a great research programme in comparing the genetic makeup of those samples with newer samples. Assuming that the populations are still there. And that there is enough documentation associated with the samples to find their original collecting sites.

A final thought. The assumptions behind the ecological niche modeling work which has been proliferating of late to predict changes in distributions, for example of crop wild relatives, is that the species don’t move or evolve fast enough to keep pace with climate change. They may well in fact evolve, adapt and survive, and that would certainly be a good thing. But helping them do that through in situ protection should not be an argument for downplaying the complementary importance of ex situ conservation. After all, with the kind of selection pressures likely to be involved, populations are very likely to be significantly genetically narrower in the future. Whether the species adapts or not, we’ll still need to collect seeds and store them in genebanks if we are to have available for use as much as possible of the genetic diversity that is currently — just — still in the field.