This famous quote from the film “Jurassic Park” is actually not as vacuous as you might expect from a Hollywood blockbuster. In fact it is pretty well true. Life does tend to find ways to spread, adapt, survive, and prosper, even in the most unlikely environments and situations. And how life finds its way tells us a lot about how evolution works.
Recently on the Biologos website, a young-earth creationist expressed doubt that evolutionary processes could work, since the probability of just the right mutation coming along to produce the right change in phenotype is so low. He linked an article on creation.com* on the topic. These are some of the things the author says:
Why would anyone expect a deactivated gene to stick around for a million years or more while an unlikely new function develops?
…gene duplication is usually, though not always, bad.
New functions arising through duplication are not impossible, but they are vanishingly unlikely,..
I answered these points with the following comment:
“Richard Dawkins wrote a book called Climbing Mount Improbable, which deals with this issue very well. The title alone gives the answer. What biology can do that nothing else can is overcome statistical improbability to an amazing degree.
If we start with a population of a million cells growing on a dish and add a poison, they will all die. But if first add a mutagenic chemical, we find that many of the cells (say 10%) will develop mutations. The majority of those mutations will be harmful, and 90% of those mutated cells will die. That leaves 10,000 cells in the dish with nonlethal mutations.
Now we add the poison. All of the cells with no mutations die. What about the 10,000 mutated cells? Almost all of them die also, because their mutations do nothing useful about the poison. But 2 of those 10,000 (0.02%) cells have a mutation that changes the way the cell transports or metabolizes or excretes the poison, and those 2 cells survive. And they reproduce. And after a few days, we don’t see an empty dish. We see a dish with two visible colonies of healthy, growing cells. With a week or so, the dish is full of cells that have resisted the poison. I have personally done such experiments.
Yes, this is microevolution. The cells are still the same species, but a mutation has overcome enormous odds, in this case 2 in a million – and it doesn’t matter how rare, unusual, or unlikely such an event is, because biology doesn’t care about statistics: all it needs is one success. One in a thousand or (if the population is large enough) one in a billion. Statistical arguments just don’t work until we get to values on the order of 10-20. Above that, saying that something is unlikely in has no import in biology.
As I have said many times, analogies to software, human information systems, systems engineering, civil engineering like building bridges, and other non-biological systems are simply not useful when trying to understand the biological world. While those are wonderful systems that humans can be proud of, they pale to insignificance when we contemplate the wonders of God’s amazing creation – life.
Life is remarkable, because it can indeed find a way. Not always, of course, and there are real constraints on what life can do. We are learning more and more about those constraints, and finding some of the basic laws that life must follow. But within that very broad framework, there is so much possibility, so many avenues of progress, that we can only stand in awe at the magnificent, divine handiwork of evolutionary action in the making of life’s diversity.