The Implications of Evolution after the Dawn of Agriculture

Another day, another three chapters, another timeline.


The readings here were largely aimed at Evolutionary Psychology’s idea of Universal Man. Indeed, look at how both the medium and fast theories of evolution would have allowed significant genetic change after the dawn of farming. The “long” theory (which would hold about 50,000) was left out of the timeline, both because it is out of context to the others and that it seems odd that the human brain could start shrinking after evolution had effectively ended.

Topic: Timeline
“the Tasmanians had no way of making fire, no boomerangs or spear throwers, no specialized stole tools, no axes with handles, no canoes, no sewing needles, and no ability to fish. Amazingly, the archaeological record shows that their ancestors from the Australian mainland had arrived with these technologies ten thousand years before.” (Pinker 69)
“Further, as populations of our direct ancestors diverged around 50,000 years ago (or earlier, depending on whose account you believe), and began to occupy different parts of the glove, the different habitats they encountered would have prompted different behavioral responses, at least some of which would have involved nice construction.” (Pinker 102) (also partial man, see below)
“life-history traits of the transplanted guppies evolved significantly within a mere eighteen generations” (Pinker 111) (equivalent to 360 years for human population)”)
from previous reading:

Sometime before the year 1900 a retired schoolteacher in Granby, Massachusetts, by the name of Abbie, took up the “mouse fancying” hobby…. She also noticed that some strains got cancer more often than others; this hint was picked up by Yale Universities and became the basis of early studies of cancer.” (Ridley 50)
“…it can take another several hundred [200 generations * 20 years / generation = 4 TYA) to several thousand [9000 generations * 20 years/generation = 180 TYA] generations for the population to adapt to the new environment — depending on whether a new mutation is required.” (Buller 56)
“The invention of agriculture some 10,000 years (four hundred generations) ago; the industrialization of Western societies some 200 years (eight generations) ago…” (Buller 57-58)
“Surprisingly, the fossil record suggests that there has been a rather steep decline in the size of the human brain during the past 15,000 years, partly but not wholly reflecting a shrinking body that seems to have accompanied the arrival of dense and “civilized” human settlements.” (Ridley 35)

Topic: Limitation of Knowledge
“Since selection build solutions to adaptive problems by retaining modifications to preexisting structures … we can never infer that the structure of an evolved solution to an adaptive problem from the nature of the problem itself.” (Pinker 104)
“there is hardly a shorter way of giving a rule for what goes on [in a cell’s development that just describing what it does.” (Pinker 126)

Topic: nature / nurture, culture
“To the extent that they can be teased apart, nature prevails over one kind of (shared) nurture when it comes to defining differences in personality, intelligence, and health between people within the same society.” (Ridley 75)
“Paradoxically, therefore, the more equal we make society [in terms of opportunities], the higher heritability will be, and the more genes will matter.” (Pinker 77)
“evenin such a prototypically “cultural” thing as religion, the impact of genes cannot be ignored and can be measured.” (Ridley 80)
“In each case a little over 40 percent of the variation [in personality type] is due to direct genetic factors, less than 10 percent due to shared environmental influences (i.e., mostly the family), and about 25 percent due to unique environmental influences experienced by the individual…” (Ridley 83) (obvious SysAdmin implications)
“… heritability depends entirely on context. The heritability of personality may be high in a group of middle-class Americans who have experienced equivalent, even identical, patterns of nurture. But throw a few orphans from Sudan or the offspring of headhunters from New Guinea into the sample and the heritability of personality would probably drop rather fast: now environment would matter.” (Ridley 86-87)
“Heritability is usually highest for those features of human nature caused by many genes rather than by the action of single genes… As Eric Turkheimer, a researcher who studies twins, puts it, “Does anyone really suppose that unintelligent, unattractive, greedy, impulsive, emotionally unstable, or alcoholic people are no more likely than anyone else to become criminals or that any of these characteristics could be completely independent of genetic endowment.” (Ridley 87)
“The phenomena we call “culture” naturally arises as people pol and accumulate their discoveries, and as they institute conventions to coordinate their labors and adjudicate their conflicts.” (Pinker 60)
“A mind unequipped to discern other people’s beliefs and intentions, even if it can learn in other ways, is incapable of the kind of learning that perpetuates culture.” (Pinker 62)
“human conformity… has a genuine rational… the first is informational, the desire to benefit from other people’s knowledge and judgement… much of what we call culture is simply accumulated local wisdom… the second motive for conformity is normative…. there is no good reason for people to drive on the first side of the road as opposed to the left side, or vice versa, but there is every reason for people to drive on the same side.” (Pinker 63-64)
“matrilocal families allows men to invest in children who are guaranteed to carry some of their genes.” (Pinker 64)
“In his book The Construction of Social Reality (not to be confused with the social construction of reality), the philosopher John Searle points out that certain facts are objectively true just because people act as if they are true. For example, it is a matter of fact, not opinion, that George W. Bush is the forty-third president of the United States…” (Pinker 64-65)

Topic: Memetics
“Many scientists now use the mathematical tools of epidemiology (how diseases spread) or of population biology (how genes and organisms spread) to model the evolution of culture. They have shown how a tendency of people to adopt the innovations of other people can lead to effects that we understand using metaphors like epidemics, wildfire, snowballs, adn tipping points.” (Pinker 65)
“Far from being self-preserving monoliths, cultures are porous and constantly in flux.” (Pinker 66)

Topic: SysAdmin
“But no one can fail to notice that some cultures can accomplish things that all people want (like health and comfort) better than others… In his trilogy Race and Culture, Migrations and Cultures, and Conquest and Cultures, the economist Thomas Sowell explained his starting point for an analysis of cultural differences… “Cultures do not exist as simply static “differences” to be celebrated but compete with one another as better and worse ways of getting things done — better and worse, not from the standpoint of some observer, but form the standpoint of the peoples themselves, as they cope and aspire amid the gritty realities of life.”” (Pinker 67)
“The “culture” of any of the conquering nations of Europe, such as Britain, is in fact a greatest-hits collection of inventions assembled across thousands of miles and years.” (Pinker 68)

Topic: Universal Man
“As [Evolutionary Psychologists] Tooby and Cosmides say, “the psychic unity of humankind — that is, a universal and uniform human nature — is necessarily imposed to the extent and along those dimenstions that our psychologies are collections of complex adaptions.” (Pinker 112)
“Evolutionary Psychology really claims that what we have in common beneath all our individual differences is a set of “developmental programs,” which produce our psychological mechanism [but EP renders] the idea of a universal developmental program for the human mind plausible only by treating genetic swithces as external tot he putative universal development program” (Pinker 123)

Topic: Particular Man
“Among white people, about one birth in every 125 consists of two non-identical, fraternal, or “dizygotic” twins — derived from two zygotes or fertilized eggs. The rate is higher among Africans and lower among Asians.” (Ridley 76)
“The correlation between the resulting scores [on belief surveys] for identical twins related apart is 62 percent; for paternal twins reared apart it is just 2 person.” (Ridley 79) (The data behind the rest of this long quote was already covered on tdaxp).
“The correlation between brain volume and IQ is about 90 percent… Eric Turkheimer found that the heritability of IQ depends strongly on socioeconomic status (Ridley 89-90)
“… the influence of genes increases and the influence of shared environment gradually disappears with age.” (Ridley 91)
“From the point of view of the evolutionary biologist this is a scandal. Why is there so much “normal” genetic variation, or, to give it its proper name, polymorphism?” (Ridley 94)
“… there is considerable variation in the lifestyles of extant hunter-gatherer populations.. there is considerably such variation among the African hunter-gatherers in and around the region Evolutionary Psychologists believe was inhabited by our ancestors [and thus is most genetically diverse?].” (Pinker 95)
“Studies of 178 mammal and 151 bird species have shown that closely related species are more similar with respect to morphological and life-history traits that are distantly related species, but that degree of relatedness isn’t correlated with similarity in behavioral traits. Rather, similarity of ecological conditions is a more important determinant of similarity of behavioral traits than is degree of relatedness.” (Pinker 96)
“For evolutionary functional analysis presupposes that there were relatively stable adaptive problems during human evolution to which selection very slowly tailored psychological solutions.” (Pinker 99) (yet domestication of cattle on Pinker 111, etc, show a changing environment)
“nice construction typically accelerates the pace of evolution as successive generations continually modify the sources of selection acting on themselves and subsequent generations… And Reznick and his colleagues were able to identify both the genetic basis of this change and the mechanism by which selection drove it (namely, differential mortality by predation)” (Pinker 111)
“Thus, it is overwhelmingly likely that there has been some adaptive psychological evolution since the end of the Pleistocene, which has rendered contemporary humans psychologically different from their Pleistocene ancestors.” (Pinker 112) (and from each other???)
“Males and females don’t have to differ in hundreds or thousands of genes [but only one] to differ profoundly in their reproductive anatomy… Tooby and Cosmides actually acknowledge that the differences in adaptions between males and females result from a single genetic switch, adn they grant that single-gene adaptive differences are an exception to the argument from sexual recombination.”” (Pinker 115)
“Some “local situations” can favor a genetic switch. For example, when the fitness of a phenotype depends on its frequency in a population [is predictable] … on the other hand, there are some circumstances to which systems of adaptive plasticity are better adapted than genetic switches. In particular, when the environment is rapidly changing and unpredictable…” (Pinker 117-118)
“My point is that, even if genetic variation produces only differences in the quantitative properties of a shared feature, it doesn’t follow that those quantitative differences are not alternative adaptions.” (Pinker 121)

Topic: Definitions
g, derived from correlation different IQ tests remains a powerful predictor of how well a child will do at school…. a high correlation between g and volume of gray matter [exists too]… ” (Ridley 89) (SysAdmin implications)
Flynn effect … average IQ scores are rising steadily at the rate of at least five points per decade.” (Ridley 95)
“[Cooperative equilibria is] arbitrary but coordinated choices.” (Pinker 64)
social fact depends entirely on the willingness of people to treat it as fact.” (Pinker 65)
“[hierarchical reductionism] consists not of replacing one field of knowledge with another but of connecting or unifying them.” (Pinker 70)
“[Adaptionism is] an attitude that “regards natural selection as so powerful and the constraints upon it so few that direct production of adaption through its operation becomes the primary cause of nearly all organism form, function, and behavior” (Buller 83) (in other words, minimization of genetic drift and possibly sexual selection)
“”[Exaption” designates] traits that “evolved for other usages (or for no function at all), and [were] later ‘coopted’ for their current role.” .. Evolutionary Psychologists would agree that psychological exaptions outnumber adaptions “by orders of magnitude”” (Buller 84-85)
“[Spandrel], a feature of an organism that originated by the “laws of growth” as a developmental by-product of an adaption.” (Buller 84)
adaptive reasoning in evolutionary functional analysis involves three steps… identification of the adaptive problems… interfering the psychological mechanism that must have evolved to solve those adaptive problems… conducting experiments to determine whether humans possess the predicted psychological mechanisms.” (Pinker 91-92)
Reverse engineering is a process of figuring out the design of a mechanism on the basis of an analysis of the tasks it performs [as is done in Evolutionary Psychology].” (Pinker 92-93)
“the social intelligence hypothesis (also known as the Machiavellian intelligence hypothesis) [argues] most of human psychological evolution was driven by the human social environment [and thus] the primary driving force of human psychological evolution was human psychology.” (Pinker 99-100)
thesis of ancient providence [means] Evolution Psychologists believe that the evolved structure of the mind “reflects completed rather than ongoing selection”‘ (Pinker 107)

2 thoughts on “The Implications of Evolution after the Dawn of Agriculture”

  1. you work really hard. I even dont have patience to read them all. part of the reason is i dont understand most…:P

  2. 520 – Thanks! I am sure if I was patient enough to copy whole paragraphs without typos the notes would be a lot easier to understand! 🙂

    I do apologize for the habit of posting notes for classes. Hopefully someone will get something out of it. 🙂

    There's only one thing to do if something's not understood. Ask. Make a comment. Bloggers can't bite, but they can sometimes entertain (and even inform).

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