W210 said:
I wouldnt say that a virus evolved until it sprouted chicken legs and started chasing and infecting people.
So, in other words,
you define what evolution is, and not scientists? So what you've been telling us is that you don't believe in
your definition of evolution.
It’s true, the evidence for evolution will not live up to your misunderstanding of it. Evolution is not about “improvements,” though that is often one of its results. Life forms don’t become “better;” they become better able to survive the conditions they find themselves in. But if those “better and improved” life-forms suddenly find themselves in conditions that are opposite to what they developed in, they will perish. So better is relative.
But there is no uncertainty about the process of evolution through natural selection. That theory is as well established as any scientific theory we have, and indeed better than most. Not only is evolution itself well established as the framework for the development of life on earth, but we know with confidence a great many details about the evolution of many species, including humans.
Homo sapiens--modern man—belongs to the phylum Vertebrata. So, also, do all the mammals, fish, birds, amphibians, and reptiles that have ever walked, crawled, flown, slithered, or swum in every corner of the Earth. All vertebrates share a common pattern of basic architecture, which has remained unchanged over millions of years despite the superficial, specialized adaptations that on first consideration might seem to divide the countless species we see around us. Though they differ in surface detail, all are variations on the theme of DNA and the 30 million ways by which it propagates itself. Every living organism that exists today is the product of a chain of successive mutations that has continued over millions of years.
Darwin did not set out to prove evolution because it reflected any ideas he might have had about how societies should function, or because he found it emotionally appealing. He ended up proposing it because he found it best explained the facts available to him. (And the concept of evolution was not something new that came with Darwin. Like so many ideas, it can be traced back to ancient Greece. What Darwin did was offer for the first time an explanation of how evolution could work in a way that was free of supernatural underpinnings.)
Evolution does indeed offer a consistent and comprehensive interpretation of the facts accumulated from a whole range of disciplines that include paleontology, geology, zoology, botany, embryology, biochemistry, comparative anatomy, anthropology, and behavioral psychology, to name just some. It establishes a common framework within which observations collected from many fields of investigation and tested independently all fit together and have reason for being the way they are. The facts are explained.
What can be said in this respect of creationism? First, it offers no reason why—why the anatomy of different species should show any relatedness at all; why the fossil record should show its progressive accumulation of change; why embryos of different species should be more alike at earlier phases of growth, why isolated populations should diverge….The inevitable rejoinder that “it was made that way” merely acquiesces to the fact; it explains nothing. We could say the same about anything and add not one scrap to our understanding of it. But on the other hand, creationist theory requires the assumption that a creator exists, that a supernatural judge of morals exists who is concerned about the day-to-day affairs of people on this planet, that it communicated its motives to chosen writers of ancient books, that those writers were correct, and honest, in interpreting the source of their inspiration, that later translators were equally infallible…and a long list of similar premises that no scientist would entertain for a moment as a basis for constructing a theory.
A scientific theory explains most and assumes least. Creationism explains nothing and assumes everything.
If you don’t believe in evolutionary theory, do you have another
scientific theory to replace it, or are you just setting a model example for us of avoidance and denial?
Keep in mind, any explanation for a process has to be consistent with both the historical and fossil evidence and with our knowledge of the abilities of present-day humans and other species. We should also apply Ockham’s razor, and make our explanations as simple as possible, based on the minimum number of (plausible) assumptions. Provided that we proceed in such a fashion, anyone who thinks we have it wrong will have an obligation to come up with a better explanation—a better fit with the known facts and with Ockham’s razor.