Swimming in Air
Anyone who has ever seen some video footage on how the marine snail known as the “Spanish Dancer” (Hexabranchus sanguineus) or such dorso-ventrally flattened fishes like skates and rays move under water (the manta ray, often even leaping into the air) or how penguins dart through the water in pursuit of little fish will agree: they fly under water.
Increases of some structures appear to parallel decreases in others
It seems odd, but no animal with horns or antlers, whether fossil or recent, has all the teeth required to give it the complete and full dentition characteristics of mammals. No species of spider is known to possess the ability to sting, but all have a poisonous bite (although, luckily only a few possess poisons potent enough to harm humans). The most colourful birds like tropical parrots and Papua New Guinea birds-of-paradise leave a lot to be desired when it comes to their ability to sing and the increase in swim speeds of fish like the tuna apparently went hand in hand with the loss of the buoyancy organ, the swim bladder. There are lots more of such examples, but what am I trying to demonstrate with these examples? I’m trying to show that the development in one area frequently has consequences in another and that a “push” in one evolutionary direction can see a reversal in another. —>—>
Arachno-Technology: Is there such a thing at all?
My grandfather, who was not a zoologist at all, but a tea merchant, always had a spider in a cage on his desk. Since most species of spiders in temperate countries do not live longer than a year or two, it was not always the same individual that entertained him (and me). Collectively, all these spiders had one thing in common: they all spun silk, which is why spiders are scientifically called Araneae (named after Arachne, who had challenged the goddess Athena to a weaving contest and promptly was turned into a spider as a punishment for such impertinence). —>—>