fin-speedy-evolution-1475500384.jpg

While not everyone might be a professional biologist, most of us are passably familiar with the concept of evolution and how it works. We know for a fact that species will gradually change to adapt to their physical environment, and we know for a fact that this process takes thousands upon thousands of years – except when it doesn’t...

Because it seems that sometimes evolution can actually happen in the blink of an eye (relatively speaking) and species can evolve rapidly enough for humans to observe and document the change. And one such change has been observed in a species that’s very familiar to many keen aquarists – the Stickleback. Although it was previously thought impossible, scientists have discovered that a population of sticklebacks that originated in the same streams is splitting into two separate species before our very eyes.

Three-Spined sticklebacks were only introduced to Lake Constance in Switzerland around 150 years ago, but the single population has already begun splitting into two separate types: one that lives in the main lake and another that lives in the streams that flow into it. The two types are physically distinct - the lake-dwellers are consistently larger and have tougher armour with longer spines than their stream-dwelling brethren – and the scientists have found that rather than just being cosmetic, the differences between the two types extend down to the genetic level.

It’s a discovery that is helping science to re-think some of the previously-held beliefs about evolution, and as more and more examples of this kind of rapid change are being found, scientists are even beginning to theorise that “speedy evolution” may even be the norm, rather than the exception...