Evolutionary theory inevitably requires large amounts of time, since the whole idea is that many small changes, when added together, result in very large changes, and the small changes have to happen sequentially, and each takes time. Fine and good, and I’m not arguing against the principle. Two questions arise, however:
- Is it reasonable to conclude that all features of living creatures can be explained as the result of successive small changes, each one of which had to confer a selectable advantage?
- Has there really been enough time to accommodate all of the necessary changes?
Let’s consider a popular example of evolution in action: albino blind cavefish. Apparently, millions of years ago, populations of the fish were trapped in underground caves, where their eyes and skin pigment served no purpose, and in fact could be detrimental (eyes as a point of infection, pigment (melanin) as a wasteful use of protein). It is not hard to understand how natural selection would result in the eyeless fish we can now study (scales actually grow over the holes where the eyes used to be). This is what we would call microevolution. No new genetic code describing new features appeared. In fact, there was only a loss of genetic information, which is why this example is usually only used to illustrate natural selection, not as serious support for evolutionary theory.
Years ago, when I first heard about the cavefish, my gut feeling was that there wasn’t actually a loss of genetic information, but rather a deactivation of code. We know that environmental factors and events during embryonic development can trigger the activation/deactivation of genes, and I figured that the dark environment probably caused a deactivation of the genes that trigger the growth of the eye. I found it very interesting, then, to discover this article. So it turns out that millions of years of separation and evolution only altered the development of a few features, but you still have a fish which can become a parent to normal fish. Huh.
Regarding the need for TIME … life on this planet is estimated to have appeared around 3.8 billions years ago, not long after the earth itself was formed (4.5 billion years ago). Let’s ignore the coincidence of life spontaneously arising so soon after the earth’s formation, and consider that amount of time: 3.8 billion years. Is that really so much time? An Intel Core Duo processor can execute 59 billion instructions in one second. If you actually break down the number of individual changes that would have had to happen sequentially to arrive at a modern human, then I think you’d find that evolution would have to clip along at a pretty good pace. Since there is obviously going to be a huge spectrum of rate of change, you have to figure that some changes would happen exponentially faster than other changes. In all the years that scientists have been examining the natural world, you’d think we’d have at least ONE clear-cut, irrefutable example of complicated new features arising as the result of sequential mutations which introduced new genetic instructions.
Can all features of living beings result from successive individual changes, each of which provided a selectable advantage?