Rattling Around

Nope, eye complexity doesn't convince me of Intelligent Design; quite the contrary. The wonderful diversity of eyes convinces me of evolution! If there is any one thing that would make me consider that Intelligent Designer, it would be the amazing, wonderful and unique water molecule!! Now that is a far-out design. It is liquid over such a wide range of temperatures, it dissolves so many things, it's frozen form (ice) is expanded compared to the liquid form (so that ice floats on water), it has such a high heat capacity, and such a high surface tension. Hydrogen bonds are so important in so many biochemical molecules and reactions. Water seems to be inextricably linked with life (at least the life forms we know of), and everywhere we find liquid water we find life (so far). Ask your local chemist or biologist what makes water so special...

The incredible variation among eyes is a strongly convincing argument (to me) of evolution. Yes, some are highly complex, while others are exceedingly simple. The amazing thing is that there are so many, many different kinds of eyes. There are different designs for image formation, though many eyes don't form true images at all. There is such an astounding variety of ways to solve the various problems of light perception. Ours eyes have one point of high acuity in each eye, but others may have a band of focus along the horizon (to spot predators), or two focus points (that must be odd; I wonder if they can concentrate on both at once, or switch back and forth?). Our eyes have a circular pupil, but there is a beautiful range of pupil shapes (and of course now you can buy contacts with many of those patterns; snake, gecko, cat, goat, etc.). We have only one type of eye, but actually most species with eyes have two types, compound and simple. There are some fish that have double-eyes, with one form for looking out of the water and another for looking into the water. We have two eyes, but again, most eyed species have more than two (remember, most species are insects!). Our eyes are in our head, but scallop eyes are around their foot! (well, sort of) The more you look at the incredible world of animals, the more you appreciate how many different kinds of eyes there are. And to me, this is a sign of varying selective pressures operating through evolution. So if there are still some ID holdouts, how do you explain the vestigial eyes of cave fish? Their eyes don't work! Was their designer just mocking them?

Ah, so where does Intelligent Design (ID) fit into all this? One of the arguments for ID is that the eye is too complex to have happened by chance. But not all eyes are designed alike! For example, the octopus eye is quite different from the usual eye of a mammal (such as humans). Both eyes are more or less round, with a retinal layer of receptors (rods and cones). Both have blood vessels nourishing the retina, and have nerve cells to connect the receptors to the brain. In the octopus, those vessels and nerves are in back of the receptors, out of the way, and the receptors point towards the light coming into the eye. But in mammals, it's backwards, with the blood vessels and nerves blocking some of the light from getting to the receptors. And since your brain is not inside your eyeball, the optic nerve has to leave the eyeball to get to the brain. That exit point can't have any receptors, which is why you have a blind spot in each eye. It certainly seems like that Intelligent Designer liked the octopus better than man, since its eye got a more intelligent design. Makes you wonder...

There are lots of animals with vision advantages compared to humans. Some can see into the infrared and some into the ultraviolet. Some can see light polarization (without wearing special sunglasses). And of course there are other senses that detect electric fields (sharks), magnetic fields (birds), temperature differences (rattlesnakes), pressure changes (fish), sonar echoes (bats and dolphins), seismic vibrations (antlions). Even plants have senses (light, gravity, etc.). I do have some ideas on why humans are special, though. Maybe in a later post I'll write about them.

Yes, even President Bush believes in evolution. How do I know? Because he is making plans for the eventual bird flu pandemic. Now, we can't have that pandemic with the current bird flu, since it is not able to transmit directly from human to human. We would have to have gene modification in at least one flu virus to get this new form, and then that form would have to spread through the virus population (mostly happening by passing from person to person). Then we would have the pandemic. But as that form spread, its gene frequencies would be increasing in the overall bird flu population... thus, evolution!

So even though President Bush speaks out for Intelligent Design (as opposed to Evolution), his actions show that he believes in evolution.

So somebody said to me, that gene frequency stuff is just microevolution... there's no evidence for macroevolution. Oh yeah? Seen any dinosaurs lately? Extinction is one of the processes of macroevolution. Or don't you believe in dinos? (OK, I'll admit no human has seen a live dinosaur... yet.) But there are extinctions that have occurred in recent times. There used to be so many passenger pigeons that the weight of roosting birds would break limbs on trees. Now they are extinct, along with the funny-looking dodo. The last passenger pigeon (named Martha) died in 1914 at the Cincinnati Zoo. Today, there are species going extinct each year, especially in some of the richest ecosystems, like tropical forests, which have such huge habitat destruction going on.

Evolution is a change of gene frequency in a population. So you have all seen it happen in your lifetimes! For example, take the population of cats in your neighborhood. When you moved in, let's say there were three grey Siamese cats. But now those Siamese are no longer around (one died of old age, one wandered off, and one got hit by the garbage truck). There are still cats, though: two tabbies, a huge coon cat that belongs to the codger down the street, a mean old orange cat, and a feral black cat that just had five kittens. So the population of "cats in your neighborhood" is now different; and by the way I have described them, their gene frequencies are different than when you moved in. Voila!! You have witnessed evolution in operation. So what do evolutionary scientists study? Just the things that happened in your neighborhood: births, deaths, migrations, and the selective pressures that affect any of those three processes.

I will be exploring speculations on biology, cosmology, and maybe science fiction, fantasy, games, and anime. Irashaimase!