The predominant current-day meaning of genotype is the DNA passed to the organism by its parents at the organism’s conception. The phenotype is the physical and behavioral characteristics of the organism, for example, size and shape, metabolic activities, and patterns of movement. To examine the relationship between the genotype and the phenotype is to be drawn into investigations that include: Continue reading
Five offspring of a couple in a remote area of Turkey grew up walking quadrupedally on their hands and feet, as portrayed in the popular science documentary ‘Family That Walks on All Fours.’ Among the various angles of research on the siblings was genetic analysis identifying a mutation in a gene on chromosome 17 influencing cerebellum development and the work of certain evolutionary biologists try to link this gene to the evolution of human bipedalism 3 million years ago. Indeed, other deleterious effects of the gene are depicted as reversing the progress in fine motor coordination and intelligence that accompanied human evolution. Continue reading
“They are in you and in me; they created us, body and mind; and their preservation is the ultimate rationale for our existence… Now they go by the name of genes, and we are their survival machines.” Dawkins, The Selfish Gene (1976)
In other words, the genes we have are those that gave our ancestors advantage over competitors in survival and reproduction. Any gene that does not give an advantage will die out—will not survive.
As the previous post noted, “parameters, such as the ‘fitness’ of [i.e., the advantage conferred by] genes or genotypes… are difficult or impossible to estimate,” even in well-controlled laboratory populations. Continue reading
Biology textbooks usually define evolution as a change of gene frequencies in populations over time. A change in the frequency of some observed trait over time might be related to changes in environmental conditions and reversed if those conditions revert to earlier levels.
Evolution could be defined as a change of trait frequencies in populations over time, leaving for investigation whether the change is reversible, accompanied by a change of gene frequencies, and so on. Continue reading
Notes from presentation, 10/11/2006.
Studying biological evolution requires us to note six features:
— There is a diversity of forms and patterns in that diversity
— There is a geological record and patterns in this record
— Organisms tend to be adapted to their environment
— Characters or features of organisms are part of an organized form which is developed anew each generation
— There is change over time and sometimes improvement over observable time.
— All life and change occurs at some place/ in some circumstances Continue reading
It would be interesting to investigate why the constructionist perspective on ecological complexity (see below) is overlooked. One answer is that people haven’t come across what has been written on that perspective by me and others. But I’m more interested in why hasn’t it been discovered and enunciated by others for themselves and why they don’t discuss its implications once they know about it. This post presents the idea again (quoting from a 2010 post, which draws from Taylor 2005, 3-17) then reviews Robert May’s response to it over the last 30 years. Continue reading
Introduction to my essay review of
Biology Under the Influence: Dialectical Essays on Ecology, Agriculture, and Health, by Richard Lewontin and Richard Levins, Monthly Review Press, 2007
In “A Program for Biology,” one of this collection’s thirty-one essays, the Marxist biologists Richard Lewontin and Richard Levins (hereon: L&L) list recent “big mistakes” in scientific approaches to complex phenomena: “the green revolution, the epidemiological transition [from infectious to chronic diseases], sociobiology, the reification of intelligence testing, and the current fetishism of the genome.” They attribute such mistakes to the “posing [of] problems too narrowly, treating what is variable as if it were constant and even universal, and offering answers on a single level only” (p.81). What they point to is not simply the “philosophical tradition of reductionism,” but also “the institutional fragmentation of research, and the political economy of knowledge as a commodity” (p.9). Indeed, their critical position extends beyond science to rejection of “the greed and brutality and smugness of late capitalism” (p.373).
Their anti-capitalist stance notwithstanding, the foci or starting points of L&L’s essays, like their 1986 collection, The Dialectical Biologist, lies in research in the life sciences. Regarding the green revolution, for example, L&L see:
…that a view based on unidirectional causation leads to the expectation that since grasses need nitrogen, a genotype that takes up more nitrogen would be more productive; since pesticides kill pests, their widespread use would protect crops; and since people eat food, increased yields would alleviate hunger (p.84).
The actual outcomes did not end up matching such simple causation because:
…the increase in wheat yield was partly achieved by breeding for dwarf plants that are more vulnerable to weeds and to flooding; the killing of pests was accompanied by the killing of their natural enemies, their replacement by other pests, and the evolution of pesticide resistance. The successful yield increases encouraged the diversion of land from legumes. The technical packages of fertilizers, pesticides, irrigation, and mechanization promoted class differentiation in the countryside and displacement of peasants (p.84).
“A Program for Biology” ends with three fundamental questions for the study of complexity:
Why are things the way they are instead of a little bit different (the question of homeostasis, self-regulation, and stability)? Why are things the way they are instead of very different (the question of evolution, history, and development)? And what is the relevance to the rest of the world? (p.86)
The third question, rephrased in a later essay as “how [do we] intervene in these complex processes to make things better for us”? (p.115), invites… readers to ask what L&L’s essays tell us about having an effect—direct or indirect—on the complex processes of the production and application of scientific knowledge. The essay review approaches this third question as it relates to social studies of science and technology and L&L’s contributions from four angles:
- a more vigorous culture of science criticism;
- a visible college of Marxist scientists in the USA;
- inquiries into the diverse social influences shaping science; and
- motivating readers who want to pursue their science as a political project.
Indirect contributions—influences on and appropriations by other actors in the wider realm of biology as politics—are discussed as well as the more direct effects.