Tuesday, May 02, 2006

Does evolution depend on abiogenesis?

When discussing ‘new life forms’ that are supposed to arise from evolution, Norman Geisler and Frank Turek, in their apologetic work, I Don’t Have Enough Faith to Be an Atheist, point out that the most difficult problem for evolution is that Darwinists can’t explain where the first life came from:

If Darwinists don’t have an explanation for the first life, then what’s the point of speaking about new life forms? The process of macroevolution, if it’s possible at all, can’t even begin unless there’s preexisting life. (pg 139)

This argument is similar to one used in this article on evolution, posted on the apologetic website, Stand to Reason. Gregory Koukl, the author, states that for evolution to be a fact, two things are needed: (1) life coming from non-life (i.e., abiogenesis), and (2) change in that life from simple forms to complex forms over time. He then states that nobody knows how life arose, and then argues:

Evolution is claimed to be a fact, but you can't have the fact of evolution unless you have the fact of abiogenesis. Yet nobody knows how such a thing could ever take place. And if life can't be shown to have come from non-life, then the game can't even get started.

One thing is correct in the above argument: scientists don’t yet know how first life arose, although there are some tantalising theories (see here). But is it then valid to argue that evolution is not true because we don’t know how abiogenesis occurred? I don’t think it is.

The above argument does not consider the fact that we can actually observe evolution happening. Many new species have been observed to have formed through evolutionary processes (see
here for examples). Not only can we see evolution happening but there are many clues, from many different spheres of research, that suggest that evolution has occurred throughout the ages (see here). The evidence for evolution is so good that evolutionary theory does not depend at all on the validity of abiogenesis. In other words, evolution happens, irrespective of what we know (or don’t know) about the formation of first life.

I will highlight the weakness of the argument further with this analogy. It is not a perfect analogy but it will do the trick. Humankind has only recently, over the last few centuries, discovered the exact process involved in conception. Would it be logical for someone in the Middle Ages, for example, to deny that humans physically grow from babies into adults because Middle Age society lacks complete knowledge of how life begins in the womb?

No. This conclusion is fallacious in that we can observe people growing and developing physically all around us. In other words, physical development in a human individual happens, irrespective of what we know (or don’t know) about the formation of life in the womb.

So not only is this argument an appeal to ignorance, but it also wrongly assumes that the truth of evolution somehow depends on the validity of abiogenesis.


Anonymous said...

Hi Kev
Rob sparrow here, not sure if you remember me. Not too clued up on evolotion, but have some idea on Physics and Cosmology. Thing about evolution is that asssumes time frame is too short if the process of evelotion is merely random. How do Carbon molecules form themselves into the complexisities seen in a human body. Micro - evoltion (Within species)and can be studied(Biblically : From the seed of the rich gentic code enbedded in Adam, all Human Races that exists today were formed, some form of mutation must have occured, because features of an African and an Asian are vastly different.i.e micro evoltion) . But Do you really have Faith in Macro- Evlotion (Cross species) If you do, then full accpetance of this Faith (by definition Evolotion is a Faith and a religion)Would mean you believe that Polar bears came from Whales???? How many billions of years would you need for this to happen... Physics tells us that our universe is around 15 billion years old (evidence from cosmic microwave backround?) the idea of intelligent design is for me far more logical accpetable than an idea random selection. things tend to chaos, not order without the exsitence of some interferrence, to line the "correct ducks in a row." so to speak. The odds of us existing today are so improbable...yet we do exists. the big question for me is Who is this great designer? Can I know Him.What meaning has my life all I become is plant food when I die.

If there is a God, how will I explain myself one day standing(or groveling) before Him? Especially if I've been privlieged with the knowledge of how to restore man's relationship with His creator. Kev, I hope that you seriously think things through to the end conclussion. Maybe one day, I'll read the blog of an EX-ex Christian. You know a lot, I know, but I pray that you can experience GOD. No doubts.
Keep Searching...keep knocking

Kevin Parry said...

Hi Rob

Great to hear from you again – long time, no hear. I just want to say thank you for the time you have spent reading and commenting on my blog.

You are definitely right about one thing in your post – if evolution is purely random, present life would not have evolved in the 13 billion years that the universe has been in existence. However, the surprising thing about biological evolution is that it is not, contrary to popular belief, random. Sure, mutations that occur in living organisms are random, but the very mechanism of evolution (ie, natural selection) that selects positive mutations over negative mutations is by nature non-random. This is because selection is the opposite of chance. So it is quite possible to get our present life evolving in the 4 billion years of earth’s existence.

It took a while for me to understand that non-randomness and order can occur without the aid of intelligence.

And I do believe in macroevolution. I don’t believe in it by faith, but I believe it because the evidence for it is so overwhelming that I would be intellectually dishonest with myself for denying it after all that I’ve read. Moreover, my unbelief in God has nothing to do with my belief in evolution. Evolution does not disprove (or prove) the existence of God. All that evolution does is describe how living organisms change over time. There are many Christians who have no problems with macroevolution, it does not pose any threat to their faith. If I became a Christian again, I will still believe in macroevolution.

Thanks again for the comments, and please visit again soon.

All the best.