Notes on Evolution and Behavioral Genetics

The Theory of Evolution

  • Explanation for the diversity of life on Earth (Pearson, 1896).

  • Accounts for similarities across life forms and the development of new species.

  • Based on the premise of abiogenesis, which has its critics.

Fundamental Theories

  • Physics encapsulates existence, including human life.

  • Solar System originated from a Population III star (Kerr, 2021), implying "we are stardust".

  • All sciences are governed by physics laws: quantum mechanics (indeterministic nature).

Historical Context

  • Charles Darwin (1809-1882), co-developer of the Theory of Evolution.

  • Influenced by his voyage on H.M.S. Beagle (1831-1836).

Key Factors in Evolution

  • Variation: Minor differences in traits among individuals.

  • Heredity: Traits are passed from parents to offspring.

  • Competition: Individuals compete for resources; successful traits are reproduced.

Natural Selection

  • Effective competitors leave more offspring, inheriting successful traits and adapting to environments.

Genetics Overview

  • Gregor Mendel (1822-1884): father of modern genetics through pea plant experiments.

  • Gene: Fundamental hereditary unit; segment of DNA on a chromosome.

Alleles and Zygosity

  • Allele: Variation of a gene affecting protein functionality.

  • Zygosity: Similarity of alleles for a trait.

    • Homozygous: Identical alleles (XX, xx).

    • Heterozygous: Two different alleles (Xx).

Genetic Traits Example

  • Eye color: Dominant (B) and recessive (b) alleles.

  • Offspring can have brown eyes (Bb) or blue eyes (bb).

Mutations

  • Random events in gene reproduction; most are deleterious or neutral, some beneficial.

Randomness in Mutations

  • Quantum mechanics implies nature is indeterministic; genetic determinism should not be assumed.

Altruism in Evolution

  • Paradox: Altruism vs. "Survival of the fittest".

  • Kin Selection: Explains altruism through shared gene propagation (Hamilton's rule).

Hamilton's Rule for Altruism

  • Altruism favored: rB > C.

  • r = relatedness, B = fitness benefit to recipient, C = cost to altruist.

Recommended Readings/Watch

  • Chapter III in Holt et al. (2023).

  • Various educational videos on human behavioral biology and evolutionary psychology.

References

  • Key texts and studies on evolution, genetics, and altruistic behavior.