Published in 1859, Charles Darwin’s On the Origin of Species made a number of bold claims about the nature of evolution – including the suggestion that an animal species with greater diversity in its line will produce more sub-species, too.
This assumption is not as obvious as you might think at first. Only a couple of years ago, this hypothesis was finally found to be true for birds. Now, researchers from the University of Cambridge in the UK have shown that Darwin was right on this point for mammals, too: Mammal subspecies are indeed important in evolutionary terms, and perhaps more so than previously thought.
Apart from being an important contribution to our understanding of evolution in general, the findings could also be useful in ongoing conservation efforts – helping experts to figure out which species need to be protected in order to ensure their survival.
“My research investigating the relationship between species and the variety of subspecies proves that subspecies play a critical role in long-term evolutionary dynamics and in future evolution of species,” says biological anthropologist Laura van Holstein.
“And they always have, which is what Darwin suspected when he was defining what a species actually was.”
Darwin actually called them “varieties”, but the idea is the same – groups within a species with their own traits and breeding ranges. There are three subspecies of northern giraffe, for example, and 45 subspecies – the highest in the animal kingdom – of the red fox.