Last edited by Cardinal; 01-04-14 at 01:21 AM.
So, picture first a species evolves a type of cell that is sensitive to light. It's just a flat cluster of cells on a patch of skin, or whatever you call the surface of this early critter. By itself, this doesn't do much. All it does is sense a change in ambient light levels. But that's useful, isn't it? A flicker of shadow might warn this creature of an approaching predator - or prey. It's not much yet, but it only has to be slightly beneficial to provide just a little survival benefit to eventually become a dominant feature. Next, one of these critters has a mutation that makes that patch of cells curved a bit. The curved shape starts to give some directional cues. Oh, it's dark over that way. Now this creature "sees" better than before. Although it's still primitive sight, just sensing dark and light. More curvature would lead to better directional cues, eventually you get an almost eye-socket-like shape. Then maybe the light sensing cells start to differentiate a little bit, start to pick up color. Or muscle structure forms around it, able to open and close the opening slightly, acting like a primitive iris. Over time, incremental changes result in incrementally better visual acuity, which has an obvious survival benefit.
I don't see any reason it should be steady. These are random mutations, after all. That incrementally better adaptation might occur in 10,000 generations one time, and 50,000 generations the next. A change that is substantially beneficial would dominate faster, and a change that is only slightly beneficial would dominate slower. Plus, factors that affect the mutation rate aren't necessarily steady. For example, the amount of cosmic radiation the earth is receiving changes as our solar system travels through the galaxy. Or the sun itself has never been a particularly steady output of radiation. Atmospheric conditions change too.It seems to me that evolution, as described above, would proceed at a fairly regular and steady pace over the many hundreds of millions of years that life has been "evolving". Wouldn't you agree? But if im not mistaken, the rate at which new species or phyla appear has not been steady at all has it? When was the last time a new phyla appeared? How would the 30 million years that preceeded today compare with other periods of earth's history as it regards the appearance of new species or phyla?
Probably a far broader question than you realize.
What is the rate of mutation for dna molecules?
I would suggest that 4.6 billion years is a ****load of time. You're the first person I've ever heard of describing 4.6 billion years as "mere." It's not "mere," it's an amount of time that stretches the limits of human understanding.It seems to me there may be plenty of good reasons to be skeptical about evolution as an answer to the question of our existence. Please understand, I know that animals evolve. I know evolution is real, for what that is worth. I can see fossil evidence that horses were small and now they are big, for example. Hehe. But that is far from turning a single cell organism into Sophia Vergara in a mere 4.6 billion years.
I guess you could say every single species we've found that isn't still around. Over a long enough time frame, you either go extinct or you continue.by the way. How many of those "dead end species" have we found fossil evidence of so far?
edit: Although the dinosaurs' inability to adapt to GIANT ****ING METEOR is understandable.
Last edited by Deuce; 01-04-14 at 01:39 AM.
One of you will end up here next!