Not everyone believes in abiogenesis and evolution. Some people believe the Bible’s account of how life originated; it was created by God only a few thousand years ago.
Believers in abiogenesis and creation both agree that new varieties of life are constantly being produced by a process called natural selection. An examination of how this process works might show whether abiogenesis or creation is the most likely starting point for it.
When some individuals are better adapted to their environment than others they are more likely to survive and produce offspring. If members of a species are found in a variety of different environments the characteristics that aid survival may be different in different areas and over time the organisms in each location will come to differ from each other as well as from the parent species.
Perhaps the most obvious example of natural selection is the many breeds of dogs that are all descended from a common ancestor. Some breeds are the result of deliberate breeding by people who wanted dogs that had specific characteristics. This is artificial selection rather than natural selection but it works the same way; dogs having the desired characteristic are allowed to reproduce but others are not.
The selection process is similar to what a sculptor does when he makes a statue out of a block of marble; he cuts away all of the unwanted parts of the marble but doesn’t add any material from outside. Natural selection works by the elimination of unwanted or undesirable genes. No new genes are produced. The common ancestor of dogs must have possessed all the the genetic information that is found in all breeds of dogs. This process goes back further; dogs, wolves, foxes, coyotes, and jackals have a common ancestor that possessed greater genetic diversity.
There is no way this process could have started with a simple one celled organism. (I mean simple in comparison with the life that exists today; even the simplest form of life is extremely complex.) Natural selection wouldn’t work because there would be too little to select from; it would be like a sculptor trying to make a large statue out of a grain of sand.
But what about the Bible’s account of creation?
God created different kinds of life. If each of these kinds had a large gene pool with the potential for producing many different varieties of descendants their creation would lead to the process of natural selection we see today.And God said, “Let the earth bring forth living creatures according to their kinds—livestock and creeping things and beasts of the earth according to their kinds.” And it was so. And God made the beasts of the earth according to their kinds and the livestock according to their kinds, and everything that creeps on the ground according to its kind. And God saw that it was good.
Genesis 1:24-25 ESV
We aren’t told how many kinds there were but the number was small enough for Noah to take a pair of each kind onto the ark. Some people don’t believe the flood occurred because the ark wouldn’t have been big enough for all of the varieties of life that exist today. When you take the results of natural selection into account you can see that the number of animals Noah needed was very small.
The term natural selection was first used by Charles Darwin in Origin of Species, which was published in 1859. Our knowledge of genetics began with experiments performed by Gregor Mendel. The results of these experiments weren’t published until after his death in 1884 so Darwin knew nothing about them when he did the research for his book.
Darwin saw natural selection taking place but because he didn’t understand how heredity works he misinterpreted what he saw. He thought that the process produced completely new characteristics and therefore was evidence that his theories about the origin of life were true. Today almost everyone shares this belief and few people realize that the things we have learned about genetics since then have produced evidence that the belief isn’t true.