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In essence, it amounts simply to the idea that non-random reproduction, where there is hereditary variation, has consequences that are far-reaching if there is time for them to be cumulative.
biology. The difference is one of complexity of design. Biology is the study of complicated things that give the appearance of having been designed for a purpose. Physics is the study of simple things that do not tempt us to invoke design.
Machines are the direct products of living objects; they derive their complexity and design from living objects, and they are diagnostic of the existence of life on a planet. The same goes for fossils, skeletons and dead bodies.
The answer we have arrived at is that complicated things have some quality, specifiable in advance, that is highly unlikely to have been acquired by random chance alone.
It is because we internally use our visual information and our sound information in different ways and for different purposes that the sensations of seeing and hearing are so different. It is not directly because of the physical differences between light and sound.
Even if we found one example that we couldn’t explain, we should hesitate to draw any grandiose conclusions from the fact of our own inability.
Mutation is random; natural selection is the very opposite of random.
The answer, Darwin’s answer, is by gradual, step-by-step transformations from simple beginnings, from primordial entities sufficiently simple to have come into existence by chance. Each successive change in the gradual evolutionary process was simple enough, relative to its predecessor, to have arisen by chance. But the whole sequence of cumulative steps constitutes anything but a chance process, when you consider the complexity of the final end-product relative to the original starting point.
In single-step selection the entities selected or sorted, pebbles or whatever they are, are sorted once and for all. In cumulative selection, on the other hand, they ‘reproduce’; or in some other way the results of one sieving process are fed into a subsequent sieving, which is fed into …, and so on. The entities are subjected to selection or sorting over many ‘generations’ in succession. The end-product of one generation of selection is the starting point for the next generation of selection, and so on for many generations.
Evolution has no long-term goal. There is no long-distance target, no final perfection to serve as a criterion for selection, although human vanity cherishes the absurd notion that our species is the final goal of evolution. In real life, the criterion for selection is always short-term, either simple survival or, more generally, reproductive success.
The progeny in any one generation are different from their parent in random directions. But which of those progeny is selected to go forward into the next generation is not random. This is where Darwinian selection comes in. The criterion for selection is not the genes themselves, but the bodies whose shape the genes influence through DEVELOPMENT.
In nature, the usual selecting agent is direct, stark and simple. It is the grim reaper.
For those, like me, who are not mathematicians, the computer can be a powerful friend to the imagination. Like mathematics, it doesn’t only stretch the imagination. It also disciplines and controls it.
The idea is that a race of animals that regularly erupts in plagues gains the benefit of alternately ‘swamping’ and starving its enemies, predators or parasites. And if these plagues are carefully timed to occur a prime number of years apart, it makes it that much more difficult for the enemies to synchronize their own life cycles.
Those gaping soldiers were prepared to die for the queen, not because they loved their mother, not because they had been drilled in the ideals of patriotism, but simply because their brains and their jaws were built by genes stamped from the master die carried in the queen herself. They behaved like brave soldiers because they had inherited the genes of a long line of ancestral queens whose lives, and whose genes, had been saved by soldiers as brave as themselves.
What lies at the heart of every living thing is not a fire, not warm breath, not a ‘spark of life’. It is information, words, instructions. If you want a metaphor, don’t think of fires and sparks and breath. Think, instead, of a billion discrete, digital characters carved in tablets of crystal. If you want to understand life, don’t think about vibrant, throbbing gels and oozes, think about information technology.
DNA is ROM. It can be read millions of times over, but only written to once — when it is first assembled at the birth of the cell in which it resides.
All of us, all human beings, have the same set of DNA addresses, but not necessarily the same contents of those addresses. That is the main reason why we are all different from each other.
Although vertical transmission down the archives of the species is ultimately what ‘success’ means, the criterion for success is normally the action that the genes have on bodies, by means of their sideways transmission.
Instead, what we find is that natural selection exerts a braking effect on evolution. The baseline rate of evolution, in the absence of natural selection, is the maximum possible rate. That is synonymous with the mutation rate.
This is that living organisms exist for the benefit of DNA rather than the other way around.
Each individual organism should be seen as a temporary vehicle, in which DNA messages spend a tiny fraction of their geological lifetimes.
It is not breath, not wind, not any kind of elixir or potion. It is not a substance at all, it is a property, the property of self-replication. This is the basic ingredient of cumulative selection. There must somehow, as a consequence of the ordinary laws of physics, come into being self-copying entities or, as I shall call them, replicators.
My thesis will be that events that we commonly call miracles are not supernatural, but are part of a spectrum of more-or-less improbable natural events. A miracle, in other words, if it occurs at all, is a tremendous stroke of luck. Events don’t fall neatly into natural events versus miracles.
Our subjective judgement of what seems like a good bet is irrelevant to what is actually a good bet.
If a theory of the origin of life is sufficiently ‘plausible’ to satisfy our subjective judgement of plausibility, it is then too ‘plausible’ to account for the paucity of life in the universe as we observe it.
Natural selection may only subtract, but mutation can add.
A gene has the particular effect that it does only because there is an existing structure upon which to work.
The particular effects that genes have are not intrinsic properties of those genes. They are properties of embryological processes, existing processes whose details may be changed by genes, acting in particular places and at particular times during embryonic development.
However ‘hostile’ the weather and other inanimate conditions may seem to be, they have no necessary tendency to get steadily more hostile. Living enemies, seen over the evolutionary timescale, have exactly that tendency.
It may be convenient to think of an arms race between two lineages such as cattle and grass, or gazelles and cheetahs, but we should never lose sight of the fact that both participants have other enemies against whom they are simultaneously running other arms races.
Predators become better equipped for killing, but at the same time prey become better equipped to avoid being killed, so the net result is no change in the rate of successful killings.
Unfortunately, natural selection doesn’t care about total economies, and it has no room for cartels and agreements. There has been an arms race in which forest trees became larger as the generations went by. At every stage of the arms race there was no intrinsic benefit in being tall for its own sake. At every stage of the arms race the only point in being tall was to be relatively taller than neighbouring trees.
It is generally characteristic of arms races, including human ones, that although all would be better off if none of them escalated, so long as one of them escalates none can afford not to.
Bodies evolve integrated and coherent purposefulness because genes are selected in the environment provided by other genes within the same species. But because genes are also selected in the environment provided by other genes in different species, arms races develop.
Darwin, although he laid his main stress on survival and the struggle for existence, recognized that existence and survival were only means to an end. That end was reproduction.
Genes may be carried in a body but not expressed.
Any individual, of either sex, is likely to contain both genes for making males have a certain quality, and genes for making females prefer that selfsame quality, whatever that quality might be.
Any gene that makes individuals behave altruistically towards bearers of such a label has a good statistical chance of aiding copies of itself: for brothers have a good statistical chance of sharing genes.
If critical mass and take-off are important elements in any success story, there is bound to be a lot of luck, and there is also plenty of scope for manipulation and exploitation by people that understand the system.
If we think of genes as ‘instructions to a developing embryo’, a gene for inserting extra segments may read, simply, ‘more of the same here’.
Speciation is the process by which a single species becomes two species, one of which may be the same as the original single one.
The reason the ‘transition’ from ancestral species to descendant species appears to be abrupt and jerky is simply that, when we look at a series of fossils from any one place, we are probably not looking at an evolutionary event at all: we are looking at a migrational event, the arrival of a new species from another geographical area.
The theory of punctuated equilibrium is a gradualist theory, albeit it emphasizes long periods of stasis intervening between relatively short bursts of gradualistic evolution.
747 saltationism is, indeed, just a watered-down form of creationism. Putting it the other way around, divine creation is the ultimate in saltation. It is the ultimate leap from inanimate clay to fully formed man.
Development is admittedly a very different process from evolution but, nevertheless, anyone sceptical of the very possibility of a transition from single cell to man has only to contemplate his own foetal beginnings to have his doubts allayed.
The editor of Biblical Creation has written: it is undeniable that the credibility of our religious and scientific position has been greatly strengthened by the recent lapse in neo-Darwinian morale. And this is something we must exploit to the full.
Such is the breathtaking speciesism of our Christian-inspired attitudes, the abortion of a single human zygote (most of them are destined to be spontaneously aborted anyway) can arouse more moral solicitude and righteous indignation than the vivisection of any number of intelligent adult chimpanzees!
The last common ancestor of humans and chimps lived perhaps as recently as five million years ago, definitely more recently than the common ancestor of chimps and orang-utans, and perhaps 30 million years more recently than the common ancestor of chimps and monkeys. Chimpanzees and we share more than 99 per cent of our genes.
All surviving organisms are descended from a single ancestor from which they have inherited a nearly identical, though arbitrary, genetic dictionary, identical in almost every one of its 64 DNA words.
