Wednesday, January 26, 2011

Another Creationist Intellectual Breakthrough

According to this photograph, which I took last week, creationists do not just reject evolution; they also reject standard English, confusing "ancestor" with "descendent." This is at a church in rural Oklahoma.
If you have not read the recent posts, see them below.

Monday, January 24, 2011

Monkeys and Weasels, or, Why Evolution Can Occur Rapidly

Many people, quite reasonably, wonder why they cannot see evolution happening. The usual scientific answer is that evolution happens so slowly that you cannot see it. While this is true, it is not because evolution has to be slow. Evolution can be very rapid.

Creationists never tire of saying that evolution cannot happen, because it would take forever for something to evolve. They like to use the monkey and typewriter (or, nowadays, word processor) example. Suppose you had a room—or a mall, or a continent—full of monkeys typing away at keyboards, randomly striking the keys. How long would it take for one of the monkeys to, by chance, type an entire Shakespeare play? I will not attempt the calculation, but we all know it would be a very, very long time. If the monkey and typewriter scenario were really the way that evolution works, then clearly evolution would be impossible. If we had to wait for evolution to, purely by chance, cough up a jellyfish, or a sequoia tree, or a human, we would be waiting essentially forever.

But evolution is not just a matter of chance. The mutations are produced by chance, but natural selection accumulates the good mutations non-randomly. This considerably changes the monkey and typewriter scenario. If a monkey types a letter at random, but it is the correct letter, natural selection will save it, and do the same with the second letter, the third, and so on. The monkeys, typing at random, may in this way quickly produce a work of Shakespeare, provided that each correct keystroke is preserved. Selection is a ratchet: it saves the good key strokes, and discards the bad ones. In one famous example of this process, evolutionary biologist Richard Dawkins used a computer program that started with a random series of letters. Each generation, the program introduced random mutations into the series of letters, and saved whichever mutations caused the string of letters to more closely resemble the Shakespearean phrase, “Methinks it is like a weasel.” This quote comes from Hamlet who was looking at the shapes of clouds. The clouds had random shapes but Hamlet was trying to select the ones that looked like animals. It took only about forty generations for the computer program, now popularly called the “weasel program,” to transform a string of random letters into the Shakespearean sentence. Forty generations is not very long. Therefore, in theory, evolution should proceed rapidly. The monkeys could go home before lunch.

This entry will appear in my book Life of Earth: Portrait of a Beautiful, Middle-Aged, Stressed-Out World, just released by Prometheus Books.

Wednesday, January 19, 2011

Parasite Load

There are many parallels between ecosystems and the world of free enterprise commerce. A well-functioning economy resembles a healthy ecosystem in many ways: natural selection favoring the most effective individuals, whose interactions are sometimes competitive, but are also frequently altruistic (within species) or mutualistic (between species). Every ecosystem has parasites, but any ecosystem in which parasites proliferated to the point of commandeering most of the energy flow would quickly degenerate and collapse.

The modern American economy is dominated by parasitic corporations. One such corporation is Bank of America. They are good at doing only two things: taking bailout money, and compensating their CEO. They did repay all $45 billion of their TARP money, but they continue to be incompetent at everything else. But they, the parasites, inflict their incompetence upon us, the hosts.

I have learned this through experience. I recently tried to refinance a mortgage through Bank of America, which was a fiasco. My application was reassigned to a series of five different people, and at each transition documents were lost and new rules popped up out of nowhere. Finally, I decided to terminate the application. Fortunately, I did not need the money.

What I encountered was sheer incompetence. Average consumers work hard and earn money from their work, but corporations are parasitic upon their employees and customers. In particular, financial corporations keep the entire country under a burden of usury. They are parasites on us. They give us nothing useful in return, certainly not money. When you pay back some of what you owe, on time, what you get in return is a higher interest rate (or at least that was the case until Obama’s financial overhaul package became law). Financial corporations suck America dry, drinking in a large proportion of the economy like drunk ticks.

Fortunately there is one thing we can do. We can simply choose to not participate. We can refuse to participate in the business ecosystem, burdened by its parasites, except where necessary. We can just say no to any unnecessary expenditures. I know that this is “bad for the economy” but it produces a sense of personal, even spiritual, liberation to just not buy things.

The image that I keep in mind is this. Bdelloid rotifers (is that what you were expecting?)! Fungal parasites kill them, but they simply dry up and blow away in the wind, leaving their fungal parasites behind! And that is what I am trying to do, by meditating upon the good things I have in life, and not thinking about things I would like to obtain.

Wednesday, January 12, 2011

Earth is a Lucky Planet, Part Three. Goldilocks’s Earth

In two previous essays, I discussed the Rare Earth Hypothesis of Peter Ward and Donald Brownlee. Earth is a lucky planet, first because the Sun is a stable star; and second because Jupiter and the Moon help to stabilize conditions on Earth. In this third essay, I explain how Earth itself is a mighty lucky planet.

Earth happened to form in the “habitable zone” of the new Solar System, in which temperatures were in the right range to allow water to exist in liquid form. No medium other than water is known in which lifelike processes can occur. Some scientists speculate that the liquid methane on Saturn’s moon Titan may be a medium for life. Even if this is the case, molecules move very slowly in liquid methane, and any metabolism of life forms on Titan would be very slow and the resulting life forms would be very simple. And Earth has plenty of water. The water may have been delivered to the young Earth by comets hitting it before 3.9 billion years ago. The ice in the comets melted and vaporized, creating a haze of steam, much of which was lost into space as new comets continued to rain from the sky. When the collisions became less frequent, and Earth cooled down, the steam became oceans, and water vapor saturated a hot, dense atmosphere of carbon dioxide and nitrogen gases. Mars, Earth’s little brother, also had oceans when it was a young planet.

The Earth is also just the right size. If the Earth were too large, its gravity would be so great that complex organisms (not to mention mountains or even continents) would not be able to stand up. If the Earth were too small, however, it would be unable to hold onto its atmosphere, partly due to a lack of sufficient gravity, and also because particles streaming from the Sun would have stripped the gases away. Mars, which is about half the size of Earth, has an atmosphere—just barely. Its atmosphere is about one percent as thick as ours. At first this seems strange, given that its gravity is at least one-quarter as strong as that of the Earth. But Mars is small enough that its core has cooled off and solidified. On Earth, the currents of molten lava produce a magnetic field that deflects much of the dangerous solar particle stream. Mars has no such protection. The solar particles have scoured away most of its atmosphere, as well as its surface water. When Earth and Mars first formed, they were both wet planets with carbon dioxide atmospheres. Earth kept its atmosphere, and evolved; Mars lost its atmosphere, and (apparently) died. The surface of Mars is without life; and if there is life on Mars, it is deep in the rocks and therefore microbial in size.

The fact that the Earth is not too large and not too small, and is just the right distance from the Sun, has been compared by some scientists to the story of Goldilocks, the Aryan girl who thought that she had the right to barge into somebody else’s house. She found that Baby Bear’s food and bed were “just right.” And if Earth were not “just right” in size and chemical composition, there would be no life on Earth more complex than microbes.

Our planet is also fortunate to have radioactive elements in its core. Without radioactivity, the core of the Earth might have cooled down and solidified, causing Earth to have a fate similar to that of Mars, though it would not have happened quite as quickly.

Our planet also happens to have plenty of carbon, which may be the only element from which life can be built and sustained. As any aficionado of Star Trek knows, silicon-based life forms such as the Horta are conceivable, since silicon atoms have several chemical similarities to carbon. However, silicon is probably too heavy to allow a silicon-based life form to participate in a silicon-based ecosystem. Silicon is a mineral; it is always a mineral. Carbon atoms can form carbon dioxide gas, which circulates through the atmosphere and is turned into complex molecules by photosynthesis. But silicon dioxide is quartz and just stays in the crust of any planet on which it is found.

The most obvious way in which Earth is lucky is that it has water—lots of it. Earth is not quite unique in this respect—Jupiter’s moon Europa is covered with oceans that are capped with ice. But on Earth, the water exists in all three states: ice, liquid water, and water vapor. Not only do life processes, as we know or imagine them, occur in liquid water, but water moves from oceans to continents and back in gaseous form. Europa has liquid water (kept from freezing not by any warmth from the Sun but by the pull of Jupiter’s gravitational field) but has no water cycle as does the Earth. Thus when you consider carbon and water, Earth is lucky not just in what it has but in what it can do with it: carbon and water can circulate around and around on the planet.

Ward and Brownlee conclude that simple microbial life may be common in the universe. But for advanced life to evolve, it is necessary that planetary conditions remain within certain limits for a long time. Such long term stability, and the complex life and advanced civilizations that would require such stability, appear to be vanishingly rare in the universe.

This essay is adapted from chapter 1 of my forthcoming book, Life of Earth: Portrait of a Beautiful, Middle-aged, Stressed-out World, to be released soon by Prometheus Books.

Wednesday, January 5, 2011

Transcendent Values?

I would like to begin the new year with an evolutionary insight I just had. The one aspect of religion to which some religious people cling even after they have given up many conventional doctrinal beliefs is that there really is such a thing as transcendent good and evil. No matter what planet in the universe, it is always good to treat other sentient beings with love and respect, and it is evil to harm or oppress them. (Of course, this does not apply to non-sentient beings such as the bacteria I just showered away.) That is, goodness is not simply something that worked for our species; it transcends evolutionary contingency.

Then I started thinking about dogs and cats. Dogs and cats are both altruistic, at least to the extent of having kin selection, which means that they cooperate with their close genetic relatives. But for cats, that is about as far as it goes. Housecats can be affectionate, but only because they identify us with their kin. Dogs are a different matter. They can devote themselves selflessly to the leader of the pack, whether a human or another dog. They have a very strong sense of direct reciprocal altruism. That is, cats use us, but dogs really do like us.

And this pattern relates to their method of catching prey. Cats hunt alone, whereas dogs hunt in packs. Pack altruism has evolved in dogs as a matter of survival; the only altruism cats have is a temporary affection for other animals they perceive as kin. What we consider to be transcendent values of goodness—such as mutual respect and aid—are adaptations for social animals like dogs, but not for individualistic animals like cats. If dogs were intelligent, they may even have altruistic as excessively developed as it is in humans.

Therefore, what I considered transcendent values might only be an evolutionary adaptation found in social species, such as humans and dogs. Therefore, maybe there are no universal, transcendent morals. This is not a happy insight for someone who wants to be religious, as I still do.

Of course, this makes no difference in how we actually live. Love, peace, mutual respect, and cooperation remain essential evolutionary adaptations for social species such as humans. Regardless of the theology, there is no question about how we should live during the upcoming year.

Saturday, January 1, 2011

Looking Into the Future

Welcome to a third year of evolution blogging. It is customary to look into the future at the beginning of January.

I just watched the movie Idiocracy. I know that it was released in 2005, but I just saw it. (Read this blog! It is your source of news that is no more than six years old!) It explores a simple and seemingly-irrefutable idea: that stupid people have more kids than smart people, and over time this will result in the stupidification of the human race. This is an interesting evolutionary hypothesis.

Obviously the extent of the stupidification in the movie is a humorous exaggeration. The society in the movie had food, fuel, and some waste disposal, for nobody was starving and there were no plagues. The movie is meant to make us laugh at, then think about, the things that we are doing, and that are happening to us, today. Among these are our immense production of garbage (which, in the movie, resulted in a huge garbage avalanche), the destruction of the natural world and of our farmlands, and the spread of consumer culture in which the sole function of people is to stupidly buy things, in response to advertisements that rely on our most fundamental motivation (sex). One corporation (which bought a large part of the government) has replaced all the drinking water (and crop irrigation water) with an electrolyte drink, so that water is used only in toilets. This makes us wonder if some corporations, in the world today, really have the power to run the government by their financial power, and to monopolize essential functions in our society.

There is a genetic basis for differences in intelligence among humans. However, the environmental aspect (in the womb, childhood, education, socialization) remains overwhelmingly important. Therefore the fact that, in many cases, stupid people have more kids than smart people is not likely to cause the human species to greatly stupidify itself. There is still an important role for educators such as myself. At the same time, it appears that current trends portend a significant even if not catastrophic decline in intelligence.

Movies like Idiocracy are meant to make us think, and to choose as a society that we will educate ourselves before we decline into such depths of dysfunction.