Experimental Evolution

Evolution is known to, over generations, alter the DNA of a species to better suit its environment through the natural selection of random combinations of traits in individuals.  If a member of a species is able to complete the task of reproducing better than another individual, the first’s traits will be copied into the next generation.  This usually follows the path of honing in on a specific niche, such as mice naturally selecting to better scavenge food scraps.  However, when a disaster vacates a niche’s species, evolution goes haywire.

Rather than work with theoreticals to explain what I mean by “going haywire”, I will use an example.  Coelacanth, pronounced /ˈsiːləkænθ/ or (SEE-lo-kanth), is an ancient fish.  Just by looking at it, you can tell that this is not your average tuna.  Coelacanths originated in the Devonian Period of the Paleozoic Era, over 360 million years ago, very soon after sharks, and have stayed relatively constant.  Coelacanths evolved very early on to be the best of all slow predators, pouncing when prey got near, using a flexible tail and a large powerful body for maximum acceleration.

Recently, paleontologists discovered a new fossil of Coelacanth, which had very different characteristics: a slender body and stiff, efficient tail.  What was this localized deviation, and why is it not alive today?  It turns out that the mass extinction, which may have killed the Dinosaurs 65 million years ago, may have also caused the localized extinction of cruising predators like barracudas and sharks.  In this area, there must have been an abundance of fish swimming just out of reach of the original Coelacanths, letting the lighter, faster variations within the species have more success chasing rather than lying in wait.  Through this shift in food supply, and a few million years, the species evolved into a new species of Coelacanth, who chased their prey.  A while later, the original cruisers re-inhabited the area, and out-performed these new Coelacanths.

In this playing with the form of Coelacanth, it is evident that evolution does “experiment” with new forms.  It is entirely possible that the new Coelacanths may have out-performed the other cruisers, and would be alive today.  This however was not the case, and it is now abundantly clear that Coelacanths are perfectly adapted to slow predation.