When Evolution Springs a Surprise 

When is an ox not really an ox? When it’s a muskox!

If you’ve visited our exhibition Fur, Fangs and Feathers (on until 20 March!) you will have seen the muskox positioned between the two polar bears.

Muskoxen are big, hairy, hoofed grazing mammals that live in the cold northern parts of North America and Europe.

Looking at them, you might think they’re a close relative of bovine species like yaks, buffalo and domestic cattle – but you’d be wrong.

Muskoxen are actually part of the same subfamily as sheep and goats. So why do they look like cows?

The answer is that muskoxen and the ancestors of cattle evolved to fit similar niches in their respective environments.

Both are herd animals that graze wide open plains and use their size and large horns to fend off predators.

The similarities between muskoxen and cattle are because of what scientists call convergent evolution.

This is when two species that are only distantly related face similar evolutionary pressures and develop similar features as a result.

There are a couple of other animals that are examples of convergent evolution in Fur, Fangs and Feathers.

A pronghorn trophy head, installed on the back wall, is one of them.

Pronghorns live in North America and get called American antelopes because they look a lot like antelopes.

Their role in their ecosystem is like that of antelopes in Africa. Like antelopes, they have evolved to outrun their predators – pronghorns are the fastest land animal in the Americas.

However, pronghorns are not antelopes. Their closest relatives are actually the giraffe and okapi!

Another example is the thylacine or Tasmanian tiger, sadly now extinct. If you’ve seen our specimen, you’ll know it looks a lot like a dog or a wolf.

But the families that dogs and Tasmanian tigers belong to split off from each other more than 125 million years ago, so despite their physical similarities, dogs and Tasmanian tigers are almost completely unrelated.

It can seem like an incredible coincidence that unrelated species end up with similar features, but it’s not so surprising when you consider that all animals are descended from the same handful of species, if you go back in time far enough.

Evolution is when species change to solve the problems posed by their environments – and if those problems are the same, it makes sense that the solutions are also the same.