10 December 2008

Does Darwinian Evolution claim that DNA mutations are random?

"If it could be demonstrated that any complex organ existed, which could not possibly have been formed by numerous, successive, slight modifications, my theory would absolutely break down. But I can find out no such case."
[Charles Darwin, Wikiquote]

This post forms part of a series on Mr Marshall's Random Mutator. You can find all the posts here:
  1. The Random Mutator of Perry Marshall.

  2. Is DNA Analogous to Human Language?

  3. How Random is Random Mutation in DNA?

  4. Does Darwinian Evolution Claim that DNA Mutations are Random?

Evolution vs Genetics

Darwinian Evolution came about in 1859 with the publishing of Charles Darwin's On the Origin of Species. The roots of genetics could be traced back to 1865 with the publishing of Gregor Mendel's Experiments on Plant Hybridisation. However, the importance of Mendel's work was not fully realised until the 20th century, with the modern evolutionary synthesis.

It is thus apparent that Charles Darwin made no claims about genetics. Charles Darwin tried to explain how species came about and how some traits become more widespread while others become extinct.

Mu, a Japanese word which roughly translates as 'no thing'. Kind of what Mr Marshall's Random Mutation Generator has to do with Darwinian Evolution, or evolution in general.

What is Darwinian Evolution?

As already noted, Darwinian Evolution and the modern theory of evolution are not the same thing at all. Darwinian Evolution claims the following:
  1. "If all the individuals of a species reproduced successfully, the population of that species would increase uncontrollably.

  2. Populations tend to remain about the same size from year to year.

  3. Environmental resources are limited.

  4. No two individuals in a given species are exactly alike.

  5. Much of this variation in a population can be passed on to offspring."

[Introduction to Evolution, Wikipedia]

Since resources are limited, there is a struggle among individuals of a species for survival. Darwin precisely claims that it is not chance alone which determines survival, but that survival depends on the traits of an individual which enable that individual to survive. In other words, survival of the fittest.

The modern theory of evolution thus bases its principles of natural selection and speciation on Darwinian Evolution, but Darwinian Evolution entirely lacks some of the other modern mechanisms of evolution. This is because the mechanisms of gene flow and genetic drift in particular are based on genetics, with which Darwin was unfamiliar.

What does Darwinian Evolution claim about DNA mutations?

Nothing. Absolutely nothing.

What does Mr Marshall's Random Mutation Generator have to do with Darwinian Evolution?

Nothing. Absolutely nothing.


Bryan said...

I came across the "Random Mutation Generator" as well and found it to be flawed and lacking in features to actually enable verification of evolution through experimental mutation and natural selection, so I made my own.


Its nothing amazing but I think it is possibly closer to a good representation of mutation and natural selection.

Garg the Unzola said...

Wicked! My favourite mutation is 'Sue ate donkey'.

Mas said...

It's true Darwin didn't claim mutations fuel evolution. And that this was added onto it later on in the synthetic evolution theory.

But there is a good reason why this addition has been made. Without random mutations Darwin fails to account for the appearance useful traits that natural selection selects from. Effectively making the theory of evolution obsolete.

No random mutations= no evolution

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