Evolution

Index:

Evolution

Summarizes lots of history and science, as well as the way that religion interferes with (and sometimes pretends to be) science. Remember that a theory is set of beliefs and that a theory never becomes a fact or event. Also that pseudo science is not science, but is a set of beliefs and evidence that masquerade as science, while violating at least one rule of the the scientific method. Examples of pseudo-science include:

Includes Dawkins' popularization of Hamilton's view that organisms developed to propagate their genes. The process is "blind, unconscious, and automatic".

Altruism:
Darwin said that altruism aids the group even if it is at the expense of the individual. Altruistic traits promote group survival. Hamilton proposed that altruism is in the genes; "Algebra of kin selection" (1964); "everyone" will sacrifice if he can save more than two full-blood brothers, or four half-brothers or eight first-cousins.


Chapters:

  1. Explaining the very improbable.

    "Complicated things everywhere, deserve a very special kind of explanation. We want to know how they came into existence and why they are so complicated. ... Natural selection, the blind, unconscious, automatic process which Darwin discovered, and which we now know is the explanation for the existence and apparently purposeful form of all life, has no purpose in mind. It has no mind and no mind's eye. ... It has no vision, no foresight, no sight at all."

  2. Good design.

    "Natural selection is the blind watchmaker, blind because is does not see ahead, does not plan consequences, has no purpose in view. Yet the living results of natural selection overwhelmingly impress us with the appearance of design as if by a master watchmaker, impress us with the illusion of design and planning. "

  3. Accumulating small changes.

    "Living things are too improbably and too beautifully 'designed' to come into existence by chance. How, then, did they come into existence? The answer, Darwin's answer, is by gradual, step-by-step transformation from simple beginnings, from primordial entities sufficiently simple to have come into existence by chance. ... The cumulative process is directed by non-random survival. The purpose of this chapter is to demonstrate the power of this cumulative selection as a fundamentally nonrandom process."

  4. Making tracks through animal space.

    Examples from nature.

  5. The power and the archives.

    "It is raining DNA outside ... DNA whose coded characters spell out specific instructions for building willow trees that will shed a new generation of downy seeds. ... It is raining instructions out there; it's raining programs; it's raining tree-growing, fluff-spreading algorithms."

  6. Origins and miracles.

    "Events that we commonly call miracles are not supernatural, but are part of a spectrum of more-or-less improbable natural events. A miracle, ... if it occurs at all, is a tremendous stroke of luck. ... cumulative selection can manufacture complexity while single-step selection cannot. ... once cumulative selection has got itself properly started, we need to postulate only a relatively small amount of luck in the subsequent evolution of life and intelligence."

  7. Constructive evolution.

    "Natural selection may only subtract, but mutation can add. ... mutation and natural selection together can lead, over the long span of geological time, to a building up of complexity that has more in common with addition than with subtraction. There are two main ways in which this build-up can happen ... coadapted genotypes ... [and] arms races."

  8. Explosions and spirals.

    "The successful scientist and the raving crank are separated by the quality of theri inspirations. But I suspect that this amounts ... to a difference not so much in ability to notice analogies as in ability to reject foolish analogies and pursue helpful ones. ... The reason engineers and living bodies make more use of negative[-feedback] than positive-feedback systems is that controlled regulation near an optimum is useful."

  9. Puncturing punctuationism.

    In 1972, palaeontologists Niles Eldredge and Stephen Jay Gould proposed their theory of punctuated equilibria. "They suggested that ... [some of] the fossil record['s] ... gaps are a true reflection of what really happened, [and that] ... evolution really did in some sense go in bursts, punctuating long periods of 'stasis', when no evolutionary change took place in a given lineage."

    "It is not really the gradualism of Darwin that the punctuationists oppose: gradualism means that each generation is only slightly different from the previous generation; you would have to be a saltationist to oppose that, and Eldredge and Gould are not saltationist. Rather, it turns out to be Darwin's alleged belief in the constancy of rates of evolution that they and the other punctuationists object to. ... The theory of punctuated equilibrium lies firmly within the neo-Darwinism synthesis"

  10. The one true tree of life.

    Ancestral species are difficult to represent in cladistic classifications. [This difficulty may decrease with the finding and analysis of DNA preserved in some fossil remains.]

  11. Doomed rivals.

    Addresses some of the doomed rival theories, including Lamarkism, neutralism, mutationism, and creationism.

Word frequency:

Most frequent (about 2% and more each) in this book's 134,360 words:

genes428
selection401
evolution365
animals363
species318
time292
theory252


Glossary of terms

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asymmetric arms race
"A true arms race in which success on either side is felt as failure by the other side, but the nature of the success and failure on the two sides is very different. From an evolutionary point of view asymmetric arms races are more interesting, since they are more likely to generate highly complex weapon systems." Competitors compete for different resource. An example is between cheetahs and gazelles, with cheetahs trying to eat gazelles, while the gazelles try to avoid being eaten. [See Chapter 7 of The Blind Watchmaker.]

arms race
"Arms races are run in evolutionary time ... They consist of the improvement in one lineage's (say prey animals') equipment to survive, as a direct consequence of improvement in another (say the predators') lineage's evolving equipment. " Types of arms race are: asymmetric arms race; cyclical arms race; symmetric arms race; [See Chapter 7 of The Blind Watchmaker.]

catastrophism
"Catastrophism was an eighteenth- and nineteenth-century attempt to reconcile some form of creationism with the uncomfortable facts of the fossil record." [See Chapter 9 of The Blind Watchmaker.]

coadapted genotypes
Successful genes collaborate with other genes. For example a biochemical pathway often needs a succession of enzymes, each enzyme being made by a particular gene. "The choice between ... two coevolutions doesn't come about through advance planning. It comes about simply through each gene being selected by virtue of its compatibility with the other genes that already happen to dominate the population." [See Chapter 7 of The Blind Watchmaker.]

cyclical arms race
This applies particularly to parasites and hosts. "The 'best' genes for any one generation ... are not [necessarily] the same as the best genes in future generations. What it takes to beat the current generation of parasites is no good against the next generation of evolving parasites." [See Chapter 8 of The Blind Watchmaker.]

enemy of a species
Another living thing that works to make life difficult for the species of interest. Not only is a predator an enemy of its prey, but a prey that resists being captured and devoured is an enemy of its predator. [See Chapter 7 of The Blind Watchmaker.]

negative-feedback
Gives processes a stable, controlled quality. When a perturbation occurs, it causes a result that dampens the perturbation. This can lead to stability. [See Chapter 8 of The Blind Watchmaker.]

positive feedback
Gives processes an unstable, runaway quality. When a perturbation occurs, it causes a result that amplifies the perturbation. This can lead to disaster (as in the runaway greenhouse effect). [See Chapter 8 of The Blind Watchmaker.]

symmetric arms race
"A symmetric arms race is between competitors trying to do roughly the same thing as each other." Competitors compete for the same resource. An example is when trees in a forest grow tall in competition for sunlight. [See Chapter 7 of The Blind Watchmaker.]


More Books

The Selfish Gene

Discusses W.D. Hamilton's theory of kin selection: natural selection favors genes for behaving altruistically toward close kin; this is because copies of those genes have a higher probability of being in the bodies of kin.


Links Elsewhere

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