Kalrithus wrote:Firstly, evolution is 100% observable thanks to our little "friend" the bacterium. That's how disease-causing bacteria become drug resistant or immune, it's through evolution
Was wondering when someone would bring this up, Question): Do the bacteria become a totally different species or do they adapt to introduction of outward stimuli such as our drugs. You may think of it as micro evolution but simply the bacteria do not suddenly become say a frog or a mini-horse, no they are still very much bacteria albeit ones that have become resistant to whatever medication may be sited. Humans themselves have been shown to adapt to their surroundings when they can't/won't force their surrounding to match them, as shown in some indigenous tribes that lived in mountainous areas of higher elevation. Their bodies became shorter/stockier and their lungs larger allowing them to live easier in those conditions in the span of a couple generations. Did they cease to be human because their bodies changed? What you call microevolution does not in any way prove macroevolution (or evolution on a large scale) because you are putting forth the argument that one organism can change completely into another organism which has never been observed and cannot be proven. You say that it takes many thousands of microevolutions to create a new organism, show me why you think so and give me an idea of how long you think such an event would take.
Now I don't know if you are one of those people that thinks we came from some primordial soup or whatever, but please enlighten me how things such as eyes came into being, or how human beings became able to actively reason and create when no other lifeform that we know of does so?
Okay now for a real challenge
First off it seems you're treating microevolution to be macroevolution. Microevolution is evolution within a species that doesn't change the species into another species, like say when something becomes resistant to something else (like bacteria becoming resistant to drugs or a species of lizard becoming resistant to a specific poison which is produced by their natural predators). Microevolution tends to focus on smaller groups and individuals; whereas, macroevolution is evolution of the entire species into a new species. Generally speaking it takes several microevolutions for a species to "become a new species", which isn't a sudden change, I may have been unclear before. Whatever the outward effects of evolution may be, evolution exists in DNA and the outward effects are caused by the changes in DNA. DNA mutates at random, sometimes these mutations are disadvantageous and the being with the mutation dies out, not spreading on its bad genes; however, say a beneficial mutation occurs, like maybe (going with the lizard metaphor again) the lizard can survive a very small amount more of the poison, this lizard survives and passes these genes on. That is microevolution. Let's look forward in time a bit then at that lizard's descendant (let's say 5 generations later), this lizard has undergone more microevolution than it's ancestor had and perhaps now can survive more poison and run faster. 5 more generations and another descendant can survive more poison, run faster, and has developed better camouflage. 5 more generations and another descendant can survive more poison, run faster, has developed better camouflage and is more fertile. It has been 15 generations since the first lizard, and now that lizard's descendants can survive poison well, run quickly, have better camouflage and are more fertile, however they're still the same species. Let's go forward 1 million years then. At this point the lizard's ancestors continue to carry the previous lizards' benefits but now let's say they've grown larger over time and their teeth have become sharper and their hide has become tougher. At this point so much microevolution has occurred that the newest lizard (the 1 million year and 15 generation one) has very different DNA from the first lizard. Perhaps now he has a different number of chromosomes, or his chromosomes are in different areas or a different order. Now if this lizard attempted to mate with another lizard from the first lizard's time (assuming they were opposite sexes) they either wouldn't produce offspring or their offspring would be a sterile hybrid. Now that the first lizard and the 1 million year lizard's DNA are so vastly different, they could no longer breed and produce fertile offspring. A definition of species: "the major subdivision of a genus or subgenus, regarded as the basic category of biological classification, composed of related individuals that resemble one another, are able to breed among themselves and produce fertile offspring, but are not able to breed with members of another species". At this point the first lizard and the 1 million year lizard have become a different species, and macroevolution has taken place.
Microevolution occurs more often and much faster than macroevolution, which occurs very slowly over a long period of time (like millions of years).
As for eyes. Eyes are quite simply an extension of the brain, you can even watch this in fetal development, they collect light, turn it into signals for the brain, which then deciphers them. I hope you don't try to claim that eyes are great and could only be the masterpiece of a creator, because that's simply not true. I'm not saying a creator is false, people can have what beliefs they want, what I'm saying is that eyes are greatly flawed. For one, the blood vessels supplying blood to the eyes lie on top of the tissues in the eyes that collect light, creating distortion in vision. Also, mammalian eyes in general are weird and have several blind spots. The way eyes are set up are even bad, of course I won't go into this unless probed to do so.
Now for human reason and our will to create. Firstly, you're incorrect in saying we are the only species that can reason or create. Monkeys for instance do both. They can and do make tools, and can and do solve puzzles with both logic and reason. Dogs also have reason, logic and good memory (it's easier to trick a 4 year old human than it is to trick most dogs, I mean like putting a marble under a cup, then very simply switching the cup slowly with another cup, many human 4 year olds will go to the original position of the first cup and expect to find the marble there, whereas the dog understands the marble is no longer there). Chimpanzees make and use tools constantly. From simply smashing something with a rock, to ripping the branches off a long twig in order to collect termites, and finally to sharpening long sticks with their teeth in order to hunt birds (the last example may have been orangutans, I can't quite remember) they do indeed create things.
We are, however, the only species we know of that completely understands symbolism and symbolic thought. Which is one reason why we're the only species that believes in religion, or really "believes" anything for that matter. As for why we have symbolism, and the amount of reasoning we have? I'm not well-versed on nervous system evolution so I'll look into it when I get a chance. What I do know is that symbolism and symbolic thought showed up about around the time we started to make more complex tools (symbolism came first, a while before actually, about the time when humans started to take teeth from their slain foes and bead them onto a necklace to show how dangerous they were, was shortly after the beginning of symbolic thought).
