Quotes About Evolution

To try to make a man, you would have to work at your biochemical cocktail-shaker for a period so long that the entire age of the universe would seem like an eye-blink, and even then you would not succeed.

Species are grouped together into genera, genera into orders, and orders into classes. Lions and antelopes are both members of the class Mammalia, as are we. Should we then not expect lions to refrain from killing antelopes, 'for the good of the mammals'? Surely they should hunt birds or reptiles instead, in order to prevent the extinction of the class. But then, what of the need to perpetuate the whole phylum of vertebrates?

Natural selection favours those genes that manipulate the world to ensure their own propagation. This leads to what I have called the central theorem of the extended phenotype: An animal's behaviour tends to maximize the survival of the genes 'for' that behaviour, whether or not those genes happen to be in the body of the particular animal performing it.

The long-lived gene as an evolutionary unit is not any particular physical structure but the textual archival information that is copied on down the generations. [I]t is widely distributed in space among different individuals, and widely distributed in time over many generations. [A] successful gene will be one that does well in the environments provided by these other genes that it is likely to meet in lots of different bodies.

A stick insect looks like a replicator, in that we may lay out a sequence consisting of daughter, granddaughter, great-granddaughter, etc., in which each appears to be a replica of the preceding one in the series. But suppose a flaw or blemish appears somewhere in the chain, say a stick insect is unfortunate enough to lose a leg. The blemish may last for the whole of her lifetime, but it is not passed on to the next link in the chain.

However, we must expect lies and deceit, and selfish exploitation of communication to arise whenever the interests of the genes of different individuals diverge. This will include individuals of the same species.

although evolution may seem, in some vague sense, a 'good thing', especially since we are the product of it, nothing actually 'wants' to evolve.

I shall define the God Hypothesis more defensibly: there exists a superhuman, supernatural intelligence who deliberately designed and created the universe and everything in it, including us. This book will advocate an alternative view: any creative intelligence, of sufficient complexity to design anything, comes into existence only as the end product of an extended process of gradual evolution.

The flagellar motor of bacteria is a prodigy of human nature. It drives the only known example outside of human technology of a freely rotating axle.

The evolutionary importance of the fact that genes control embryonic development is this: it means that genes are at least partly responsible for their own survival in the future, because their survival depends on the efficiency of the bodies in which they live and which they helped to build.

Natural selection is the process whereby replicators out-propagate each other. They do this by exerting phenotypic effects on the world, and it is often convenient to see those phenotypic effects as grouped together in discrete 'vehicles' such as individual organisms. This gives substance to the orthodox doctrine that each individual body can be thought of as a unitary agent maximizing one quantity—'fitness'

Natural selection favours genes that control their survival machines in such a way that they make the best use of their environment. This includes making the best use of other survival machines, both of the same and of different species.

Kamikaze behaviour and other forms of altruism and cooperation by workers are not astonishing once we accept the fact that they are sterile. The body of a normal animal is manipulated to ensure the survival of its genes both through bearing offspring and through caring for other individuals containing the same genes.

If all the evidence in the universe turned in favour of creationism, I would be the first to admit it, and I would immediately change my mind. As things stand, however, all available evidence (and there is a vast amount of it) favours evolution. It is for this reason and this reason alone that I argue for evolution with a passion that matches the passion of those who argue against it. My passion is based on evidence. Theirs, flying in the face of evidence as it does, is truly fundamentalist.

The gene's extended phenotypic effect, say an increase in the height of the dam, affects its chances of survival in precisely the same sense as in the case of a gene with a normal phenotypic effect, such as an increase in the length of the tail.

the conclusion I wish to draw is not really disputable. If host behaviour or physiology is a parasite adaptation, there must be (have been) parasite genes 'for' modifying the host, and the host modifications are therefore part of the phenotypic expression of those parasite genes. The extended phenotype reaches out of the body in whose cells the genes lie, reaches out to the living tissues of other organisms.

Los depredadores parecen bellamente diseñados para cazar a sus presas, mientras que las presas parecen igual de bellamente diseñadas para escapar de ellos. ¿De qué lado está Dios?.

the behaviour of an individual may not always be interpretable as designed to maximize its own genetic welfare: it may be maximizing somebody else's genetic welfare, in this case that of a parasite inside it.

The second point of this present chapter is that the genes that bear upon any given extended phenotypic trait may be in conflict rather than in concert with one another.

If two beavers working on the same dam have different genes for dam height, the resulting extended phenotype will reflect the interaction between the genes, in the same way as bodies reflect gene interactions.

Within each species some individuals leave more surviving offspring than others, so that the inheritable traits (genes) of the reproductively successful become more numerous in the next generation. This is natural selection: the non-random differential reproduction of genes.

it is ultimately these mistakes that make evolution possible.

Finally, at the end of the chapter, we saw that genes 'sharing' a given extended phenotypic trait might come from different species, even different phyla and different kingdoms.

One is that phenotypes that extend outside the body do not have to be inanimate artefacts: they can themselves be built of living tissue.