re: Evolution: Missing link found. Fish => Tetrapod

quote:

---

I don't pretend to fully understand but based on college courses in genetics, biology and botany what I remember is this. Genetic mutation is a natural occurrence; it happens often. Most mutations are not helpful and even harmful such as a genetic heart defect. However over millions of years and trillions of mutations rarely a naturally successful mutation coincides with an environmental change that allows said species to survive the change.

The classic and one of the most well documented examples is the English Peppered Moth LINK The misnomer is assigning logic or personification to the process. A species doesn't consciously evolve through it's own strategy, it's just a chance happenstance as a result of the favorable (lucky if you will) mutation that happened at just the right time. Most species, again a classic example was dinosaurs, were not so lucky and died out.

As such, I can imagine that over millions of years with drought conditions over a previously large swampy area/water world that a chance mutation allowed a species previously filtering oxygen from water to become able to breathe air directly. The water breathers died out due to drought conditions and could no longer reproduce obviously so the air breathers became the evolved species because they were able to survive and reproduce. It seems far fetched to be sure from our time perspective but a lot can happen over thousands even millions of years. Just think about the things we have discovered over the last 100 years.

---