What year did Darwin publish The Origin of Species?

Struggle for existence

Population growth rate is exponential but resources are limited. Organisms thus struggle for access to those resources.

What types of “resources” might be relevant for reproductive success?

Variation in traits

results in variation in fitness

These traits are heritable

offspring tend to resemble their parents

Law of segregation

Chances of passing on one of two possible alleles. For instance an “A” allele, such as brown eyes, or an “a” allele for blue eyes