Watching new species evolve in real time
|Sampling sites in the Lake Constance area and lake and stream ecotypes |
of threespine stickleback [Credit: David A. Marques et al., PLOS ONE]
Now, an elaborate genetic study conducted by researchers at Eawag and Bern University helps to explain the secret of its success: the stickleback can evidently adapt very rapidly to new habitats -- so rapidly that, for evolutionary biologists, it serves as a model for the divergence of a single species into two or more distinct species.
Rather than just one "Lake Constance stickleback," the researchers found two different forms -- typical of the lake and of inflowing streams -- even though lake stickleback migrate into these streams during the spawning season.
According to first author David Marques, "It was completely unexpected for the species to diverge over such a short period, given that the sticklebacks breed at the same time and at the same sites." Usually, independent species develop by adapting to different habitats and reproducing isolated from other populations -- at different depths of a lake, for example. Among whitefish, different breeding and spawning seasons have additionally evolved.
Source: PLOS [February 29, 2016]