A Lot of Positives

In the last few posts I have been a few of the things that seem to me to be problems with the concept of moving from some initial simple living thing to the highly complex livings we see around ourselves today by a process of random mutation and natural selection. In this post I want to talk about just one more - the length of time required (even if the process wasn't random).

Research into human and chimp DNA indicates that our DNA is about 95% to 98.5% the same as chimp DNA. That doesn't sound like much of a difference, until you realise that our DNA consists of about 3 billion bases (i.e. individual "letters" in the DNA coding). This means that even a small percentage amounts to a lot of differences. In fact, by the more conservative estimates I have come across, there are still around 40 million differences between our DNA and chimp DNA. For example here's a quote from an article from the Seattle PI:

Out of the 3 billion units of DNA, the human-chimp comparison revealed some 35 million simple changes, or mutations, in the single units of the overall sequence. They also found about 5 million additions to or subtractions from the genome involving chunks of DNA sequence.

In other words, if a chimp were to change into a human, its DNA would need to be changed 40 million times.

So how long would that take? Well, let's assume that we start off with a chimp and that the chimp has a baby that has one of those positive changes (mutations) and that baby chimp grows up and has a baby which has another positive mutation and so on until, eventually, the line has progressed to the stage where we have a human.

The length of time taken (based on the assumption that there is one positive change each generation without skipping any generations) is simply the average age of sexual maturity multiplied by the number of changes. Now chimps become mature at about age 9, and humans become mature (well, at least able to reproduce!) somewhere in their early to mid teens, so let's take age 10 as the average. That would mean that we need 40 million x 10 = 400 million years. Even if we started off with something half way between a chimp and a human (which evolved into a chimp on one hand and a human on the other), we wound need 200 million years (half of 400).

This is a bit of a problem because chimps and humans are, according to evolutionary theory, supposed to have separated only around 4 to 8 million years ago. And this assumes that there is a positive mutation each generation without negative changes getting in the way and spoiling things. Realistically, we would expect there to be a number of generations between each positive mutation to allow that mutation to spread through the population enough for it to exist in the same animal as the next positive mutation and for it to be identified as positive by natural selection. If we were to allow, say 5 generations for this in each case, the time taken would shoot up to 1 billion years (5 x 200 million). According to standard evolutionary timelines there were only very basic, single celled organisms around that long ago never mind anything as advanced as a chimp.

This means that, if the evolutionary explanation is correct, there are two possibilities:

• There have to have been multiple positive mutations happening simultaneously (somewhere between 25 and 125 or more of them per generation depending on how many generations we need to distribute the mutations around). And of course these have to be in a line that is not being subject to an equal or larger number of negative mutations. Now getting just one positive mutation is rare enough. Getting those kinds of numbers of them happening regularly is just, in my opinion, totally implausible.
• Alternatively there would need to be multiple parallel lines of evolution happening simultaneously that somehow or other suddenly combined at some point (or a various points) to form a human. This is slightly less implausible (to me), but still isn't very convincing because the outcome of this would be far more likely to be a whole range of species ranging from chimp to human rather than just the two ends of the spectrum. [As an aside this is what leads to the kind of thinking that gives people an excuse to believe that their race is more highly evolved that some other race - the kind of thinking that has caused huge racial problems in the past.]

So it seems to me that even if positive mutations happened very regularly from generation to generation, there still isn't enough time available for all the changes we would need to get from a chimp like animal to a human to happen in the time frames that even evolutionists believe are available.

Note: This is part of a series of posts about why I believe in God. See my post "You Believe that Stuff???" for more info and links to the other related posts.