Quotes About Mutation

You're right, a spleen is a strange thing-we technically don't need one, but maybe spleens are kept in our bodies in case we mutate or evolve, and if we grow wings or tentacles we need to have the spleen in place in order for them to work.

For me, the level at which natural selection causes the phenomenon of adaptation is the level of the replicator - the gene.

Transposons are just small pieces of DNA that randomly insert in the genetic code. And if they insert in the middle of the gene, they disrupt its function.

We no longer belong here, we are mutants, and our only choice is to become even more mutant so that we eventually leave and disappear from this region. We are nothing now but the residue of a defeated, conquered past and we are stubbornly holding on to old creeds, a few archaic rituals and the facade of western modernity.

Darwinism is not a theory of random chance. It is a theory of random mutation plus non-random cumulative natural selection. . . . Natural selection . . . is a non-random force, pushing towards improvement. . . . Every generation has its Darwinian failures but every individual is descended only from previous generations' successful minorities. . . . [T]here can be no going downhill - species can't get worse as a prelude to getting better. . . . There may be more than one peak.

Natural selection is a beguiling counterfeiter of deliberate purpose.

A deep understanding of Darwinism teaches us to be wary of the easy assumption that design is the only alternative to chance

Darwinism is not a theory of random chance. It is a theory of random mutation plus non-random cumulative natural selection. Why, I wonder, is it so hard for even sophisticated scientists to grasp this simple point?

senile decay is simply a by-product of the accumulation in the gene pool of late-acting lethal and semi-lethal genes, which have been allowed to slip through the net of natural selection simply because they are late-acting.

evolution is blind to the future

There is no universally agreed definition of a gene.

If there are versions of the evolution theory that deny slow gradualism, and deny the central role of natural selection, they may be true in particular cases. But they cannot be the whole truth, for they deny the very heart of the evolution theory, which gives it the power to dissolve astronomical improbabilities and explain prodigies of apparent miracle.

According to this theory then, senile decay is simply a by-product of the accumulation in the gene pool of late-acting lethal and semi-lethal genes, which have been allowed to slip through the net of natural selection simply because they are late-acting.

A gene is not indivisible, but it is seldom divided. It is either definitely present or definitely absent in the body of any given individual. A gene travels intact from grandparent to grandchild, passing straight through the intermediate generation without being merged with other genes. If genes continually blended with each other, natural selection as we now understand it would be impossible.

They have come a long way, those replicators. Now they go by the name of genes, and we are their survival machines.

Evolution is the process by which some genes become more numerous and others less numerous in the gene pool.

If a program or strategy is successful, this means that copies of it will tend to become more numerous in the population of programs and will ultimately become almost universal. It will therefore come to be surrounded by copies of itself. If it is to remain universal, therefore, it must be successful when competing against copies of itself, successful compared with rare different strategies that might arise by mutation or invasion.

It is fundamental to the idea of a replicator that when a mistake or 'mutation' does occur it is passed on to future copies: the mutation brings into existence a new kind of replicator which 'breeds true' until there is a further mutation

In principle, we may consider any portion of chromosome as a potential candidate for the title of replicator.

The word allele is nowadays customarily used of cistrons but it is clearly easy, and in the spirit of this chapter, to generalize it to any portion of chromosome.

An arbitrarily defined length of chromosome, or potential replicator, may be said to have an expected half-life, measured in generations.

But if we set selection pressures on one side, we can say something about the half-life of a replicator on the basis of its length alone. If the stretch of chromosome we choose to define as our replicator of interest is long, it will tend to have a shorter half-life than a shorter replicator, simply because it is more likely to be broken by crossing-over. A very long portion of chromosome ceases to deserve the title of replicator at all.

A mutant individual who was prepared to go on just a little bit longer would always win. So the strategy of maintaining a fixed bidding limit is unstable.

It is the effects on the world of successful active germ-line replicators that we see as adaptations.