|Feature Article - February 2010|
|by Do-While Jones|
Itís Valentineís Day, and we love to celebrate it by talking about the theory of evolutionís failure to explain the origin of sex.
There is no question that sexual reproduction has its advantages. The controversy is over how natural selection could possibly have caused sexual reproduction to arise. Letís give you some general background describing the problem, and then talk about specific issues evolutionists have been debating recently in the technical literature.
Evolutionists donít like to include abiogenesis (the origin of life) as part of the theory of evolution because they canít even begin to present a plausible scenario as to how it could happen. Without abiogenesis, the theory of evolution is literally dead on arrival. If there is no living thing to evolve, there can be no evolution.
But it is Valentineís Day, and our hearts are so overflowing with love that we are willing to give evolutionists a head start. Just for the sake of discussion, we are willing to grant them their premise that life began through some unknown, undirected natural process without so much as a laboratory full of equipment, an intelligent designer (and his deformed assistant), and a freshly assembled composite corpse. Frankencell just came to life all by himself, as if by magic. (But magic wasnít involved. It was a purely natural process! )
There are two things we know for sure about Frankencell. First, Frankencell must have reproduced. If Frankencell never reproduced, then we would not be here. Frankencell either would have died without leaving any offspring, or Frankencell would still be the only living thing on Earth. So, the reproductive process must have originated before Darwinian evolution could have occurred.
The second thing we know for sure is that Frankencell must have had the ability to grow. Frankencell must have grown large enough to reproduce.
Growth requires food. Food has to be converted into proteins, amino acids, nucleic acids, enzymes, and all that other stuff that makes up a cell, and allows the cell to grow. Thatís a problem for evolutionists, too. But, as tempting as it is to go down that path, letís not go there so we can get to the sexy part.
The difference between plants and animals is that plants can make their own food. Animals have to eat plants and/or other animals to survive. Frankencell could not have been an animal because he was the first living thing. There were no other plants or animals for Frankencell to eat. Therefore, Frankencell must have made his own food.
Green plants do this today using a complex process known as photosynthesis. Scientists agree that this process if far too complicated for a single cell like Frankencell to have used. So, there must have been another simple, effective method that Frankencell used to capture energy and convert it into food. We don't know what this process might have been, but there must have been such a process. If there wasnít, then Frankencell would have died before he could reproduce, and there would have been no evolution. Since we KNOW evolution is true, Frankencell must have had some unknown way to make his own food. But we have our mind fixed on sex, so we canít explore that evolutionary conundrum, either.
Frankencell grew large enough to reproduce. So, one February 14, long ago, Frankencell bought a box of chocolate and went looking for someone to be his Valentine. The problem is that Frankencell was the first living thing. He had not reproduced yet. He was all alone in the world. Not only were there no other living things to eat, there were no other living things to mate with.
For Frankencell to reproduce, he (Oops! We should have called him, ďit.Ē)óFor Frankencell to reproduce, it had to do it all by itself. Frankencell must have used asexual reproduction to begin the spread of life across the face of the Earth.
Already we have ignored the problem of how life began, how metabolism began, and how asexual reproduction began. We have to ignore those critical problems to get the problem of the origin of sex.
If the theory of evolution is true, Frankencell must have been an asexual plant which eventually gave rise to all the sexual plants and animals. How could this have happened through natural selection?
For a long time, Frankencell reproduced by cell division, making identical copies of itself. Then, by some fortunate mutation, Frankencell gave birth to Frankenmale. As soon as he was old enough, Frankenmale bought some flowers and chocolate and went looking for Frankengal. But all he found were Frankencells. After a long, futile search for Frankengal, Frankenmale died.
Then, one day, a fortunate mutation produced Frankengal. Every night she sat by her telephone, waiting for Frankenmale to call and ask her out on a date. But Frankenmale died many years earlier, so poor Frankengal died an old maid, without leaving any offspring.
As luck would have it, mutations produced both Frankenmale and Frankengal on the very same day. Unfortunately, the mutant Frankenmale was born in New York, and Frankengal was born in California. Since they did not know about Match.com, Frankenmale and Frankengal never found each other, and both died lonely and sexually frustrated. The world remained filled with asexual Frankencells.
But even if Frankenmale had found Frankengal, would he have known that he had to take her to dinner and a movie before he could get lucky? There are certain courtship rituals that simply canít be bypassed. Would Frankenmale have had the desire to court Frankengal? What if Frankenmale wasnít handsome or a good listener?
According to the theory of evolution, new traits evolve because they improve the ability to produce offspring. It is hard to find a mate. Some people never do. But an asexual creature just needs to find itself. Everything it needs for a good time is right there, all the time.
Sexual reproduction certainly is advantageous because, after a large gene pool exists, sexual reproduction can facilitate adaptation by randomly producing the most advantages combinations of genes. But, absent an existing gene pool, the necessity to find a partner before reproducing is a distinct disadvantage. There is no reason for natural selection to favor sexual reproduction over asexual reproduction.
Some evolutionists might try to argue that, at some point, Frankencell developed latent sexual tendencies. That is, one particular Frankencell could reproduce asexually or sexually. That Frankencell made many identical copies of itself asexually. Those offspring could reproduce sexually with each other. But why would they? They all have identical genes, so there is no advantage to gene shuffling. If they can reproduce without a partner, why find one?
We need to make this important point before we go on. Creationists and evolutionists agree that sexual reproduction has some significant advantages which can make a species more fit for survival. There is absolutely no argument about that. The disagreement is about whether or not natural selection is the mechanism by which sexual reproduction came about. Even some evolutionists have serious doubts about the power of natural selection to produce such a change.
The simple-minded (but erroneous) reasoning goes like this: Natural selection causes species that are more fit for survival to drive less fit species to extinction. Sexual reproduction makes a species more fit for survival. Therefore, sexual reproduction must be the result of natural selection. Furthermore, since sexual reproduction does exist in some species, it proves that natural selection is powerful enough to bring about a change in sexual reproduction. This circular reasoning is invalid because the premise is used to prove the conclusion, and the conclusion is used to prove the premise.
There are long-term benefits to sexual reproduction; but natural selection depends upon immediate, short-term benefits to the species in question. Frankenmale would not have had any short-term survival benefits over Frankencell. Therefore, natural selection would not have made Frankenmale more likely to produce offspring than Frankencell.
Now that you have a general understanding of the problem, presented with all the seriousness it deserves, letís look at what serious evolutionists say about the problem.
For Darwin, sex was a big question mark. "We do not even in the least know the final cause of sexuality; why new beings should be produced by the union of the two sexual elements," he wrote in 1862. "The whole subject is as yet hidden in darkness."
Today, biologists understand the molecular nuts and bolts of sex fairly well. Each new human being (or bird or bee) needs a set of chromosomes from each parent. But that's the how. The why of sex is still fairly mysterious. Bacteria don't have to search for a mate; they just grow and divide in two. An aspen tree can simply send out shoots that grow into new trees. No muss, no fuss with finding a partner, fertilizing an egg, and joining two genomes. Why should so many species take such a labyrinthine path to reproduction, when straightforward routes are available? 1
Evolutionists canít understand why sexual reproduction began because of ďthe twofold cost of sex.Ē
In 1971, the late British evolutionary biologist John Maynard Smith helped kick off the modern study of the evolution of sex by pointing out how costly sons are to a mother. An asexual female lizard, for example, produces just daughters, all of whom can reproduce. A sexually reproducing female lizard, on the other hand, produces, on average, a son for every daughter, half the reproductive potential. Yet despite this "twofold cost of sex," as Maynard Smith called it, he observed that sex is widespread, as most animals and plants produce males and females. 2
Evolutionists think that sex might have evolved as an optional way of reproduction. Perhaps a creature evolved that could reproduce asexually or sexually. This is pure speculation, of course. But, if the speculation is true, then what is the advantage to losing the asexual option and evolving into a purely sexual creature?
If sex started out as an optional way to reproduce, then a new question emerges: How did sex later become mandatory in many species, including our own? Hadany suspects that the answer has to do with sexinessóthat is, with the preference sexually reproducing organisms often have to mate with some individuals over others. 3
Sure, we enjoy sex. But that still isnít a reason to lose the option of being able to reproduce asexually.
Although sexiness may help explain how sexual reproduction took over, it can't fully explain why sex has managed to reign for billions of years. Because they don't have to pay the twofold cost of sex, under the right conditions, any new cloners ought to spread rapidly in a population, challenging sexual reproduction. However, given the rarity of asexuals, something must be getting in the way. Over the years, scientists have proposed about 20 different hypotheses to explain the failure of asexuality to regain much of a foothold. 4
None of these 20 hypotheses really work. The most popular, but admittedly inadequate explanation, is called the Red Queen hypothesis.
This model of host-parasite coevolution came to be known as the Red Queen hypothesis, after the Red Queen in Lewis Carroll's book Through the Looking Glass, who takes Alice on a run that never seems to go anywhere. "Now here, you see, it takes all the running you can do to keep in the same place," the Red Queen explains.
The Red Queen conundrum, some researchers have argued, may give an evolutionary edge to sex. Asexual strains can never beat out sexual strains, because whenever they get too successful, parasites build up and devastate the strain. Sexual organisms, meanwhile, can avoid these dramatic booms and busts because they can shuffle their genes into new combinations that are harder for parasites to adapt to.
Red Queen models for sexual reproduction are very elegant and compelling. But testing them in nature is fiendishly hard, because biologists need asexual and sexual organisms that share the same environment and parasites. 5
Even if the Red Queen hypothesis is true, it only explains why sexual reproduction is better than asexual reproduction. It doesnít explain the ORIGIN of sexual reproduction.
Since we have important Evolution in the News, and great hate mail to print this month, weíve run out of space and will have to continue this essay next month.
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Zimmer, Science, 5 June 2009, ďOrigins: On the Origin of Sexual ReproductionĒ, pp. 1254 - 1256