@neologist,
Jesus, ralk about selection bias; you're original sentence read: ". . . seems to be intelligent
design . . ." You've willfully misquoted yourself.
What design do you allege there is in nature? Life forms follow the consitions in which they exist. Two and a half billion years ago, the dominant life forms (the only life forms) were anaerobic "bacteria" (bacteria may not be a reasonable description, but it will do for this purpose). But at that time, some of them began to evolve (don't ask me by what mechanism, no one knows, although there are, of course, hypotheses). They developed the ability to photosynthesize, which meant that rather than floating around in the oceanic stew and hoping to find enough nutrients to reproduce before starving to death, they could make their own food from the available resources. The bi-product of the photosynthesis was molecular oxygen (O2). There had always been O2 in the atmosphere, but there wouldn't have been enough to strike a match--what little there was was quickly absorbed by dissolved minerals in the water or by direct contact with rocks on the surface. These new organisms, cyano-bacteria, produced enough O2 that in a mere 200,000,000 years or so, the natural means by which molecular oxygen was absorbed were no longer sufficient to remove all of the molecular oxygen. Disaster! Anaerobic organisms are called that because they don't use oxygen, and in fact, it's poisonous to them. This lead to what is called THE GREAT OXYGENATION EVENT. After that roughly 200,000,000 years, there was so much molecular oxygen in the atmosphere, and dissolving into the water, that the anaerobic organisms began to die off. It could also be called the first great extinction event, except that the lowly anaerobic bacteria are still with us--but they have to stay indoors.
It may have taken 900,000,000 years rather than 200,000,000 years. It may have reacted with the methane in the atmosphere, reducing the greenhouse effect to the point where a nearly global glaciation resulted, what is called snowball earth. It may have done a lot of things. The geological evidence, though, is undeniable for the appearance of massive amounts of O2 about two and a half billion years ago.
Life is not designed. It reacts to its environment, and it can alter its environment, too. The alterations may be lethal so some forms of life, even those forms of life which are responsible for the alteration. That's chaos, not design. That's also life, in a nutshell.
