Piscology now! Comments.
In comments on Piscology Now! Rachael asks:
Isn’t the point of evolution that over a very long amount of time things evolve in a way to become the “fittest” (in the sense of “survival of the fittest”… Coelacanth fossil’s were found of them from so long ago that people thought they were extinct. But they aren’t extinct and yet are exactly the same as the fossil’s show them. Where’s the evoluation [sic] in that?
The point is, Coelacanths have survived for at least 410 million years because they have evolved:
1. The Coelacanths alive today are not the same species as the known fossils. Unless you think God knitted new species through the eons - in which case I’m wasting my time - those lobe-fins did evolve to adapt to the inevitable changes of food, habitat and disease in the last 410 million years.
2. There are two known living species of Coelacanth, so from a common ancestor they have specified - evolved if you like.
When it comes to doing what Coelacanths do they are the fittest, no point in ‘becoming’ a salmon or a cod when their general Coelacanthyness has served them very well for longer than the dinosaurs lived. If they are subject to new seletive pressures - a change of food availability, cave prices go up and they need a new home, a new disease comes along, a section of the population ends up in a subtly different bit of sea with different conditions from home, that is when the process of evolution kicks in with noticable results - those fish with traits which help them survive in the face of new pressure succeed, breed and pass it on.
The Coelacanth story is a good one:
1. Fossils found, no living specimens, extinction assumed.
2. Living specimens caught, science joyfully updates data, the sum of knowledge is added to.
3. Occasionally, a lucky bod such as I gets to look upon a rare, rare specimen and one’s sense of wonder and curiosity is increased. Here you go, have a wonder:
Latimeria chalumnae from the spirit room of the Darwin Centre, Natural History Museum, London © Lunartalks 2007
