The Biology of War

1. The Biology of War

2. Darwinian Evolution Evolution by natural selection rests on the following set of assumptions: • There are inheritable variations among the members of a population;

3. Darwinian Evolution • Many more individuals are produced each generation than can survive and reproduce. This statement is based on Malthus' observation that populations can increase geometrically (1-2-4-8-16) while the food supply can increase only arithmetically (1-2-3-4-5);

4. Darwinian Evolution • Individuals with adaptive characteristics are more likely to be selected to reproduce by the environment;

5. Darwinian Evolution • Gradually, over long periods of time, a population can become well adapted to a particular environment click here for more on naked mole rats

6. Darwinian Evolution • The end result of organic evolution is many different species, each adapted to specific environments

7. Neo-Darwinism • Although Gregor Mendel’s work with genetics was published (in a relatively obscure journal), Darwin was unfamiliar with it or its implications • Darwin had no explanation for the transmission of these traits • Beginning in the 1930s, a synthesis between molecular biology and Darwinian evolution produced a theory and mechanism for transmission

8. Neo-Darwinism • Likewise, Freud had no underlying explanation for the sources of the instincts and drives he postulated • Both Darwin and Freudunderstood that there was a biological basis, but were unable to identify that basis

9. Neo-Darwinism • The modern synthesis of evolution is based on the following ideas and makes significant modification to Darwin’s view in its understanding of the causes contributing to evolution, to whit:

10. Neo-Darwinism • Populations contain genetic variation that arises by random (ie., not adaptively directed) mutation and recombination; • Populations evolve by changes in gene frequency brought about by random genetic drift, gene flow, and especially natural selection

11. Neo Darwinism • Most adaptive genetic variants have individually slight phenotypic effects so that phenotypic changes are gradual; • Diversification comes by speciation, which normally entails the gradual evolution of reproductive isolation among populations

12. Neo-Darwinism • These processes, continued for sufficiently long time periods, give rise to changes of such great magnitude as to warrant the designation of higher taxonomic levels (genera, families, etc.)

13. Human Evolution • Human beings possess particular species-specific psychological dispositions • These dispositions arose because in ancestral populations selection favored certain variants of each mechanism over the available alternatives • Genes for each psychological disposition became established in the human gene pool

14. Human Evolution • Note, this is not to say that we have genes for specific behaviors (with the exception of species-typical movements) • In other words, evolution has shaped the basic psychological substrate of the species

15. Freud • So the underlying question is: Does the human species have a psychological predispostion for violence and warfare?