Presentation on theme: "So Cleverly Kind Epigenetic rules vs. genetically endowed potential."— Presentation transcript:
So Cleverly Kind Epigenetic rules vs. genetically endowed potential
Human Nature Freud’s dilemma: –As we become more ‘civilized’ we must ‘renounce more and more of our innate selves. –The price of civilization is individual unhappiness. But this is familiar ground: a vision of ourselves that divides us up between an animal heritage (violent, impulsive) and a civilized, restraining overlay.
Evidence? Is there any reason to suppose this is really how things are with us? Are our ‘good’ inclinations really artificial, imposed, unnatural to us, Are our bad inclinations really natural, rooted in our evolutionary past, only to be ‘overcome’ by some recent, artificial civilizing influence? Gould thinks not, and blames this notion on dualism, theology (not to mention Manicheanism).
Manicheanism The most striking principle of Manichaean theology is its dualism. Mani postulated two natures that existed from the beginning: light and darkness. The realm of light lived in peace, while the realm of darkness was in constant conflict with itself. The universe is the temporary result of an attack from the realm of darkness on the realm of light, and was created by the Living Spirit, an emanation of the light realm, out of the mixture of light and darkness.dualism A key belief in Manichaeism is that there is no omnipotent good power. This claim addresses a theoretical part of the problem of evil by denying the infinite perfection of God and postulating the two equal and opposite powers mentioned previously. The human person is seen as a battleground for these powers: the good part is the soul (which is composed of light) and the bad part is the body (composed of dark earth). The soul defines the person and is incorruptible, but it is under the domination of a foreign power, which addressed the practical part of The Problem of Evil. Humans are said to be able to be saved from this power (matter) if they come to know who they are and identify themselves with their soul.problem of evilsoullightbodyearth
Influences of Mani Christian theology is officially not Manichean. In fact, it’s a standard heresy. But Christianity has been strongly influenced by Manichean ideas. After all, they did officially brand it a heresy. And one can’t help suspecting that some of the early issues about sexuality that troubled Christian theologians (is it better to be chaste? What happens to the religious community if everyone is expected to be chaste?) derive from the identification of the ‘dark’ with matter (and the light with ‘spirit’). Purity issues are unavoidable here…
Altruism Why is this such a focus here? One-shot PD is not solvable without altruism. Altruistic behaviour is often selected for very special praise as ethically ‘impressive’. Evolution vs. Altruism: Some, who have a limited view of what natural selection is about, imagine that evolution by NS simply cannot make sense of altruism.
But we know better Gould tells us a story about Hamilton’s work on kin-selection (and Haldane’s anticipation of the idea). So altruistic behaviour can easily evolve in a context where the recipients of the aid are related to the givers. This is particularly obvious in the widespread phenomenon of parental aid to their offspring. But it’s most striking biological success is in its applications to the eusocial insects.
Hymenoptera These are the ants, bees and wasps. There is a peculiar fact about the genetics of these insects: they are haplo-diploid. Males are haploid, that is, the males have only a half-complement (one copy each) of chromosomes (they develop from unfertilized eggs). But the females are diploid, having the usual two copies of each chromosome.
Evolution of social behaviour This is important to understanding why so many of these insects are social (and their social behaviour has, in many cases, arisen independently). By contrast, insects that are diploid have only produced one line of social insects (the termites). Aside: there is one odd species of mammal that is social in a rather similar way (the naked mole rats).
Relatedness and resources Because they are haplo-diploid, female bees and ants and wasps are genetically more similar to their sisters (75%) than they are to their own offspring (50%). But the males’ genes are 100% represented in their offspring, and only 50% represented in their sisters. So it’s hardly surprising that the males don’t do much around the colony!
Intentional language Gould self-consciously distances himself from the (ubiquitous) talk of ‘he would rather’ or ‘she prefers’ in this evolutionary context: “I do not mean to attribute conscious will to creatures with such rudimentary brains. I use such phrases as “he would rather” only as a convenient shortcut for “in the course of evolution, males who did not behave this way have been placed at a selective disadvantage and gradually eliminated.” ”
The argument from investment The force of this kind of selection appears in the sex- ratios and weight-ratios of male and female offspring. The queen, who has an equal shot at reproducing through her daughters and her sons, produces equal numbers of both. (A selective account of this can be given, if open competition for mates is assumed.) The workers are more closely related to the daughters, and feed them preferentially, producing about a 3:1 weight ratio in favour of the daughters. But slave workers don’t discriminate, and so produce a 1:1 weight ratio (except when working in their own colony instead of for the slave-making ants).
Very interesting, but… What does this tell us (if anything) about our own social behaviour? First, that our altruistic, kind side is just as natural as our violent, aggressive side. Second? Not much more than this. Here, Gould sets his heels and resists the temptation to apply sociobiological ideas to interpret human societies in any greater detail. He recognizes our genetics as allowing a wide range of potential behaviour, from the extremely aggressive and selfish to the extremely self-sacrificing. But this genetic potential is best understood, Gould thinks, in terms of flexibility, a rich range of possibilities, rather than in terms of specific ‘rules’ we tend to obey. So for Gould we are even less like ants than Ruse and Wilson suppose. (I’m inclined to think that’s a good thing…)
Homosexuality Wilson’s hypothetical explanation of (exclusive) homosexuality: –This is an evolutionary dead end for the individual. –But if the individual is able, thereby, to contribute substantially to the success of his/her relatives in raising children, that problem is potentially solved. –So in principle, there could be (at some level of frequency) selection for a gene that normally gives rise to exclusive homosexuality.
A risky strategy Gould praises Wilson’s aim, which is to argue that for some people homosexuality may be entirely natural and that therefore we should not condemn it or them. But he thinks the ‘natural therefore not to be condemned’ move is risky- what if it turns out that there is no ‘gay’ gene? Is it OK to revert to mistreating homosexuals? Instead, Gould proposes that the defense of civil rights for homosexuals should rest on familiar normative grounds: This is private, consensual behaviour in which both parties are adults and able to make their own choices. Here Gould is echoing Huxley (recall the ‘no better reason than we had before’ remark).
Determinism The contrast between ‘gene-behaviour’ determinism and Gould’s emphasis on the lability of human nature is subtle, but substantial. The ‘epigenetic rules’ account isn’t strictly speaking deterministic– our genes, on such a view, don’t fix our behaviour patterns, but they bias them strongly in particular ways, and normally result in certain particular behavioural patterns. Further, it suggests that these patterns are adaptive in particular ways.
Biological Potentiality Gould, however, thinks that our behaviour is much more flexible (at these levels). So we can pick up and learn and alter behavioural patterns. Moreover, the kinds of patterns Ruse and Wilson imagine as ‘built in’ and the result of selection may instead be the result of social evolution. No genes need to be exchanged in order for a group to take up (say) the use of iron as an important material for tool-making. Instruction and learning by example allow for much more rapid spread of advantageous behaviour patterns (and sometimes perhaps for less advantageous ones– think of fads, and worse…).