The arbitrariness of Scientific Words


…that the Clymene dolphin is actually a hybrid between two other species?

The other day this piece of news started going around the internet. A new dolphin species has emerged, called the Clymene dolphin (Stenella clymene). Well, the actual dolphin had been discovered in 1856, but it was thought to be a subspecies of the spinner dolphin (Stenella longirostris) until 1981.

In modern times, simple phenotypical and behavioural analysis has been replaced by DNA analysis. This sometimes confuses many “mere mortals”, who read the news and think “really? There was a dolphin roaming around the Atlantic and no one’s ever seen it?“. The answer to that is of course yes, we did see it, but hadn’t checked out its DNA yet. Like when a new mammal was “discovered”, maybe a year ago. It had always been there, in the museums’ archives, but no one had gotten to checking its DNA yet. And with this dolphin the situation was similar: until January of this year we thought it was a species unto itself, just like, a normal species. But the cool thing about this one is that it’s a hybrid between the spinner dolphin and the striped dolphin (Stenella coeruleoalba).

Yes, it’s interesting. Cool. But is it really so surprising? Why is everyone so excited about this piece of news? Hybrids have been around for a while: it’s simply another route that evolution/speciation takes. Right? Why all the hassle?
Maybe because in our definition of “species” one of the fundamental rules is that different species can’t have fertile offspring. Not for more than a generation or two, anyway. And here are two animals of different species (albeit same genus) having offspring and creating new species (i.e. the offspring were fertile, very much so).

Personally I think the issue doesn’t lie in the species mixing – that’s not so amazing. What’s actually being questioned is our definition of species. Who decided what a species was and what wasn’t? What made an animal a subspecies, the same species or a different genus? We did. Without DNA analysis, without a “higher understanding”, without anything, really. Just our usual certainty of being right.

But what if we weren’t? What if our definition of species….. is wrong?

clymene dolphin

The Clymene dolphin, taken from this site:

One response »

  1. Pingback: DId you know… | EcoMarghe

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