Genome

Relation between historical and biological possibility: on the time line of evolution, events that alter the environment promote evolution in one direction via natural selection; if the environment had been altered differently, evolution via natural selection could have taken a different course.

There may be impossible organisms because they are biologically impossible--they would not be sustainable because of the laws of physics and chemistry.

There are organisms that do not exist, but historically impossible at a certain point in time because biohistorical/environmental context prevents them from ever evolving.

Darwin provides a framework for biological possibility in terms of accessibility in the Library of Mendel AKA the space of all genomes. “The Library of Mendel” is the collection of all possible genomes--DNA sequences--which includes all actual organisms and all possible but not actual organisms that would be possible given a long series of selective blows to produce them. There are also biologically possible organisms that become impossible because of the way history unfolds. Though the majority of the sequences would not be sustainable organisms or recipes for anything living at all. Those that would be building instructions for possible organisms are possible only if the history of the environment allowed them to evolve.

Organisms that do not exist but that can be described does not mean that the organisms are possible--there may not be a DNA sequence--a “recipe” for it.

If a small change in the genotype can produce a large change in the phenotype, then intermediate phenotypes may not be available/possible.

Proving there is no straightforward way for biology to produce a phenotype is not a strict proof of biological impossibility.

Possibility Naturalized

Biological possibility: x is biologically possible if and only if x is an instantiation of an accessible genome or a feature of its phenotypic products

Restricted notion of biological possibility is thought of in terms of both logical/mathematical possibility & physical possibility.

Dennet sees biological possibility in terms of accessibility (from some stipulated location) in the Library of Mendel. Logic and physics are "clamped" -- their laws are and always will be the same. However biology is not clamped. Two plus two equals four now and a million years ago. However, a tiger can exist now but could not have in the environment when life began, but tigers were possible given that eukaryotes evolved as the environment changed over large periods of time. Tigers are "more possible" now than then. Critics urge that this is not "possibility" at all; Dennet says no matter, it is a replacement for biological possibility then, because a notion of all-or-nothing possibility has no investigative value.

“Defining possibility in terms of accessibility is circular.” “Accessibility” is just possibility with a new prefix. But nothing stops us from going down--accessing--a path that physics allows. Nonactual genomes are possible only in the sense that if they were formed they would be stable; but whether or not a sequence of events could lead to their being formed is addressed in terms of their accessibility from one location or another. Most of the genomes in the set of stable possibilities will never be formed because there is not enough time for events to transpire that influence their evolution by natural selection.

“Dennet’s treatment of biological possibility is ‘gene-centrist’.” Dennet’s treatment of biological possibility rules out organisms that are not an end point on some branch of the Tree of Life that has already taken us as far as we are today. But that is Darwin’s grand unification of biology. Without “special creation” or “cosmic coincidence” one must accept that every feature of the biosphere is a “fruit of the Tree of Life.” Every possible living thing is connected by descent to all other living things.

“Why should we treat biological possibility so differently from physical possibility?” (Why shouldn’t there be “laws of biology” like there are “laws of physics”?) Dennet says his definition of biological possibility does not rule out biological laws that governs the Library of Mendel, but it does put a difficult burden of proof on anyone who thinks that there are laws of biology over and above the laws of math and physics.

Language

Words give us the ability to have foresight and the ability to see beyond the immediately available options. Darwin believed that language is the prerequisite for “long trains of thought.” With language, the evolution of culture and the growth of humanity's collective knowledge is an autocatalytic process.

When generate-and-test, the basic move in any Darwinian algorithm, moves into the brains of individual organisms, it builds a series of ever more powerful systems, culminating in the deliberate, foresightful generations and testing of hypotheses and theories by human beings. This process shows no signs of “cognitive closure,” thanks to their capacity to generate and comprehend language.

Models of Mind - The Tower of Generate-and-test

Darwinian - The ground floor of the Tower. Different “hard-wired” phenotypes were “field tested”, and only the best designs survived (selection of a favored phenotype). The favored genotype multiplied. (pg. 374 Dennet)

Skinnerian - “Blindly” tries different responses to the environment until one response is selected by “reinforcement”. The next time, the creature’s first choice will be the reinforced response (if it hasn’t been killed by an early error). Ask themselves “What do I do next?”

Popperian - Make “better than chance” first moves. Has an inner selective environment that previews responses; the first time, it acts in a foresightful way (better than chance). Its inner environment contains information about the outer environment and its regularities. Ask themselves “What should I think about next?”

Gregorian - Imports mind-tools from the cultural environment; these improve both the generators and the testers. The Gregorian creature has words and other mind tools that give it an inner environment that permits it to construct ever more subtle move generators and move testers. They learn to think better about what they should think about next, and so forth, a tower of further internal reflections with no fixed or discernible limit.

When words are learned, they find homes in the brain already partially built for the concepts they express.

Chomsky & Gould

Chomsky and Gould have no religious commitments or leanings, so why are they so resistant to the idea that the human mind is the product of natural selection? Perhaps it is because they would rather the mind be a mystery, than be the result of an animals adaptation.

Chomsky believes that language makes the difference--takes the brain beyond being a mere automaton--but trying to explain how the language organ got designed is futile--there is no hope for a "reverse engineering" account. Chomsky believes that the human mind is cognitively closed, like all species’ minds, with regard to some topics. Chomsky claims that all questions are either “problems” that humans can solve or “mysteries” that we cannot.

Spiders can’t contemplate fishing, birds can’t contemplate democracy...so humans may not be able to contemplate certain things either. Note that chimpanzees cannot contemplate electrons, but chimps can’t even contemplate the question. Dennet argues that of all the books in the Library of Babel, one must contain (so there must exist) a perfect English language explanation for “mysteries” like free will and consciousness.

Chomsky’s view that language is not directly learned by a process in childhood (before our eyes), but rather it is something innate that develops in our species (it is “turned on” by a few developmental triggers and the environmental conditions determine what language the child will speak) has scientific support. However, Chomsky does not believe that the “language organ” is an adaptation produced by natural selection or that it can be explained by biology (“engineering), only that perhaps physics can illuminate it. Dennet (Darwin, Spencer) believe that “genes are the channel through which the environment speaks”, whereas Chomsky thinks that genes get their get their message from some intrinsic, ahistorical, nonenvironmental source of organizations (“physics”).

Gould suggested that language may have evolved as the by-product of selection for other abilities or as a consequence of unknown laws of growth and form. Gould endorses Chomsky’s theory of universal grammar as a bulwark against adaptationist explanations of language, and Chomsky endorsed Gould’s antiadaptationism as an authoritative excuse for rejecting evolutionary explanations for the innate establishment of universal grammar.

Dennet argues that even if language does not serve the purpose that it was designed for, it is an exaptation, which is still an adaptation. That there can be a difference between reason for selection and present utility is important.

Chomsky has been hyper-critical of tries at artificial intelligence as too simple; the attempts were perhaps too simple, but Chomsky is hostile even towards their tactics of trying for simple models.

Chomsky discovered and explained the most important crane in the human mind that lifts all aspects of culture into place, but he hates that it is treated as a crane. He is embraced, therefore, by skyhook seekers.

Evolutionary Psychology

The problems that infest the study of human emotions are that human generations live long and turn over slowly, and of course that human beings cannot be held in captivity or bred for study.

Emotion theory has made the most progress when it has taken the results of physiological or psychological investigations of emotion and looked for evolutionary explanations for them.

Darwin established a pattern of explanation for emotion in which behaviors with one function are retained to perform another function-demonstrating the importance of an historical, phylogenetic perspective on the evolutionary process. Adaptation occurs in a specific historical context, and “adaptive thinking” is the reconstruction of successive phases of evolutionary history.

Evolutionary Psychology is a response to the challenges that the difference between past and present environments of human populations poses: 1) that it makes the link between selective history and current utility fragile (adaptive stability). Traits, including behaviors, can evolve for one reason and be useful now for another reason. This is especially evident in cases where the environment has changed in important ways. 2) That it can change the developmental outcomes (new behaviors can arise) (phenotypic stability).

The appropriate grain of analysis is difficult to identify because human behaviors are often "bundled" traits. (i.e. different types of aggression)

The Modular Emotions:

Modular cognitive systems are mandatory; they are not bound by a decision; they are opaque to consciousness. They are domain specific (deal with one sort of cognitive process). Ekman's studies of human ability to associate facial expressions with correlated emotions suggest that the same facial expressions for certain emotions can be found in all human cultures. They are human universals (pancultural) but not necessarily monomorphic (exist the same in every single human).

Ekman proposed the theory that the modular emotions take the form of affect programs: complex, coordinated, and automated responses involving many different physiological systems. The affect programs occur without conscious decision whenever an appropriate stimulus is present. The system that produces them is a modular cognitive system: the person does not decide that they will happen to them.

Evolutionary Psychologists regard Ekman's study as confirming their predictions about emotions. However, while the output of the system is pan-cultural, the input to the module--the emotion stimulus--is very flexible and varies between cultures and individuals. Newborn babies respond emotionally to little else than loud noise and loss of balance with fear, except facial expressions. Contrary to the Evolutionary Psychologists' predictions, this is evidence that most human behaviors result from individual conditioning, and affect programs are designed to cope with general evolutionary problems that it can redefine as the environment changes (but learning itself is a complex ability with an evolutionary history). Still, certain stimuli (classic phobic stimuli for example) that are learned to cause certain emotions may be easier to learn and harder to lose than other associations (between fear and flowers for example).

Evolutionary psychologists treated specifics as adaptations, like "fear of predators" while evolution treated it as part of a general problem--"fear in general."

The Commitment Model:

Some emotions are not modular; they come from conscious thought processes. The affect programs are pan-cultural, while others may be culture specific. (Japanese emotion amae, deep sense of satisfaction from dependency.)

Frank proposes mechanisms that are domain specific but able to affect conscious decision making. The Commitment Model of emotion: emotions are motivations that conflict with rational calculations about immediate rewards. When an individual is known to be committed to these “irrational” behaviors in advance, he is treated will be treated differently by other agents. This different treatment can have advantages (don’t cross a vengeful person, make agreements with loyal people, etc). Frank thinks emotions are powerful and spontaneous motivations designed to enforce commitment to strategies that would otherwise be disrupted by calculations of immediate self-interest.

Signals of intention are inherently evolutionarily unstable. Individuals who can signal the intention of cooperation, for example, without following through can achieve a gain without incurring the costs. The mimic strategy can spread until the signal (facial expression) is no longer reliably associated with the behavior. Then it will be less and less advantageous to respond to the signal.

Hutterites

The possibility that memes or complexes of memes can redirect our underlying genetic proclivities is exhibited by the Hutterites.

The Hutterite sect is a group of religious fundamentalists that began in Europe. They regard themselves as a bee colony. They practice communism and promote extreme selflessness among them. Nepotism and reciprocity--which most evolutionists use to explain prosocial behavior in humans--are scorned as immoral. Giving must be without regard to biological relation or expectations of return.

The Hutterites demonstrate the importance of cultural transmission (rather than genetic) of dispositions that are part of the common human stock

Cultural evolution can create new group effects

Human beings--even the Hutterites--are not ballistic intentional systems but guided intentional systems. Guidance can be provided on a daily basis. Wilson and Sober downplay the elements of human nature--like selfishness and openness to reason--but the Hutterite social structure is arrayed against those very things. If group thinking were as much a part of human nature as they say, then Hutterite parents wouldn't have to say anything to condition their children.

Wilson and Sober are right to present the Hutterites ideals as the essence of an organismic organization, but the important difference is that human beings always have the option of opting out.The difference between human social groups and bees, for example, is there is always the option of not participating in human social arrangements, where as cells in organization and bees in a colony do not have a choice.

E.O. Wilson:

Wilson's driving concept was that some human behaviors are adaptations, molded by natural selection for some function. Behavioral differences are like other phenotypic differences. If behavioral profiles vary within a population, but are inherited from one generation to the next, then natural selection can choose among them.

Sources:
Sex and Death: An Introduction to Philosophy of Biology, by Paul E. Griffiths & Kim Sterelny
Darwin's Dangerous Idea by Daniel Dennet
River out of Eden by Richard Dawkins