Originally posted by littlefinch
reply to post by danielsil18
"Evolution only has one definition." Not trying to nitpick here, but I really dont think there's any one word that only has one definition. What
everyone else is referring to (I think) is the difference between micro and macro evolution.
Charles D-man, the guy who popularized and sort of solidified the theory of evolution (but not the first to put the idea forward), started his whole
thing by studying finches on the gallapagos islands. He noted that the finches had gained certain traits to better match their specific island
habitat, but they had all stemmed from the same species, thus they had evolved through the "survival of the fittest" method. The weak get singled
out, the strong thrive, with the traits that they need. Anyways, that evolution could be viewed over a few generations, making it micro evolution.
That has been proven.
Now since humans have only been around for so long, we have no way of witnessing Macro evolution (monkeys ----> humans) I'm not saying that Macro
evolution isn't real. It just hasn't been scientifically proven yet, but it's considered to be the most accurate theory to explain why we've
gotten here so far. Maybe someone else will come along and provide another theory that becomes the accepted truth, but i don't see that happening
Evolution is a theory like Newton's laws of physics are a theory.
The monkeys to humans debacle is where we turn to the fossil record. On that note, we evolved from apes, not monkeys. Yes, there is a rather large
difference, especially in regards to ambulation, and perhaps most obviously, our lack of tails.
We know that at some points, roughly between 6-9 million years ago as the fossil record permits it, ape-human hybrids, scientifically known as
Australopithecines, first appeared in Africa. These early ancestors of humanity varied, a lot. Some had human-like faces and chimp-like bodies, some
were arboreal, some were bipedal, some were were more gracile and others more robust, and the list goes on. The most famous A. Afarensis fossil, which
you may have heard of, is Lucy.
Anyways, fast forward a few million years and we see the rise of our species, Homo. They weren't Homo Sapiens, however, as we only came about
~200,000 years ago, according to the fossil record. Homo has been, for the most part, bipedal and rather intelligent. While Australopithecines have
been attributed to primitive tool crafting and use slightly more advanced than that employed by modern chimps, Homo Erectus employed tools like blades
fashioned from bone.
Anyways, we're about as close as we can get to proving the occurrence of evolution on both a micro and macro level. All life has to come from
something, but it also must adapt to best survive. For example, the first amphibious species was king for a short while, as it had no predators on
land. The same thing occurred with seals, for example, before predation by polar bears was introduced into their environment; they were virtually
fearless above water because they had no predators prior to the polar bear. Of course, the polar bear comes along and suddenly all those careless
seals start getting picked off one by one. The result? Fearful seals survive and have offspring who share the same traits.
One thing to keep in mind regarding evolution is that all success is relative; no evolutionary victory lasts. All life is in a race to remain extant.