Lec 8

Evolutionary theory

A framework for understanding the nature of biological change over time as explained by figures such as Wallace and Darwin.

Biogeography

The study of species across time and geographical locations.

Wallace's assumption

The idea that species in the same geographical location would be similar.

Recent geological shift

A hypothesis proposed by Wallace for the wide differences in species on Bali and Lombok.

Wallace Line

A boundary that separates species between Australia and Asia due to tectonic plate movements.

Natural selection

The mechanism by which species adapt to their environment and evolve over time.

Common ancestry

The idea that all species share a common origin.

Heritability

The genetic transmission of traits from parents to offspring.

Struggle for existence

The competition among individuals of the same species for resources necessary for survival.

Sexual selection

A form of natural selection where individuals with certain inherited characteristics are more likely than others to obtain mates.

Heterodox theory

A theory that deviates from accepted or orthodox views, often controversial.

Misappropriation of Science

The misuse of scientific ideas to serve a specific sociopolitical agenda.

Eugenics

A social philosophy advocating for the improvement of human genetic traits through selective breeding.

Sterilization Act

A 1924 Virginia law allowing for the sterilization of individuals deemed 'undesirable'.

Biological determinism

The thought that biological factors such as genetics dictate human behavior and social structure.

Advantageous traits

Traits that confer survival or reproductive benefits in a specific environment.

Environmental pressures

Influences from physical and biological surroundings that can affect species traits and evolution.

Darwin's and Wallace's main observations

Both Darwin and Wallace observed variations in species in different environments, the struggle for existence, and the role of natural selection in driving evolutionary change.

Darwin’s emphasis in his Theory

Emphasized competition among individuals

Wallace’s emphasis in his Theory

Focused on environmental and ecological pressures leading to adaptation

Wallace’s view

Environmental conditions determine fitness, making advantageous traits context-dependent. Example: Size and strength are relative to the environment's demands

Darwin's Theory of Species Origin

• Species originate from ancestral forms

• Divergence occurs via Natural and Sexual Selection

Galton

Suggests brilliance and other traits are hereditary