The Atheist's Guide to Reality_ Enjoying Life Without Illusions - Alex Rosenberg [36]
Examples are all around us. A female leopard frog will lay up to 6,000 eggs at a time—each carrying exactly half of all the order required for an almost perfect duplicate offspring. Yet out of that 6,000, the frog will produce on average only two surviving offspring. Some fish are even more inefficient, laying millions of eggs at one time just to make two more fish. Compared to that, a dandelion is miserly with seeds. It will spread only 1,000 seeds and produce, on average, one copy of itself. But the human male competes well with profligate fishes. He ejaculates millions of sperm, full of information about how to build a person, almost all capable of fertilizing an egg, and yet 999,999 sperm out of 1,000,000 fail to do it. A high proportion of most organisms go through an entire life cycle building and maintaining order and then leaving no offspring at all. Everyone has one or two maiden aunts and bachelor uncles. Insofar as Darwinian processes make reproduction central to adaptation, they rely on a wonderfully wasteful process. It’s hard to think of a better way to waste energy than to produce lots of energetically expensive copies of something and then destroy all of them except for the minimum number of copies that you need to do it all over again.
How about heredity? Another amazingly entropy-increasing process! Molecular biologists know that DNA copy fidelity is very high and therefore low in information loss compared to, say, RNA copy fidelity. But think of the costs of this much high fidelity. In every cell, there is a vast and complex apparatus whose sole function is to ensure copy fidelity: it cuts out hairpin turns when the very sticky DNA sticks to itself, it proofreads all the copies, removes mutations, breaks up molecules that could cause mutations, and so on. In Homo sapiens, at least 16 enzymes—polymerases—have so far been discovered whose sole functions are to repair different kinds of errors that thermodynamic processes produce in DNA sequences. The costs of high-fidelity heredity—both to build the equipment that protects and corrects the DNA sequences and to operate it—are very great. Just what the second law requires.
Now let’s look at this energy waste on an even larger scale. The evolution of adaptations reflects environmental change over the course of Earth’s history. The vast diversification of flora and fauna is also the result of differences between local environments in different places on Earth. Since long before continental drift and long after global warming, environments on Earth change over time and increase entropy as they do so. What is more, once natural selection kicks in, flora and fauna remake their environments in ways that further accelerate entropy increase. When nature started selecting molecules for stability and replicability, it began producing arms races more wasteful than anything the Americans and Soviets could ever have dreamed up. From that time on, there has been a succession of moves and countermoves in adaptatve space made at every level of organization. It has happened within and between all the descending lineage of molecules, genes, cells, and organisms. Each line of descent has forever searched for ways to exploit its collaborators’ and its competitors’ adaptations. All that jockeying for position is wasted when one organism, family, lineage, species is made extinct by the actions of another organism, family, lineage, species. This, of course, is what Darwin called the struggle for survival.
Add sexual reproduction to the struggle for survival and it’s impossible to avoid the conclusion that Darwinian selection must be nature’s favorite way of obeying the second law. Natural selection invests energy in the cumulative packaging of coadapted traits in individual organisms just to break them apart in meiosis—the division of the sex cells. Then it extinguishes the traits and their carriers in a persistent spiral of creative destruction. Think