Observations from videos:

multiple insects focused on one in aggressive manor, attacking the individual multiple times

one individual (walrus?) showing dominance against another by forcing it off rocks, territorial

horses that look alike stay together and eat together, different colored horses separate further once they have more space one horse lies down, different colored horses approach all observing lower body of fallen horse, horse stands up and appears to walk normally with the other similar color horse to get water


video 1: is this fighting for reproduction? fighting for alpha? why are there multiple attacking one?

video 2: are these animals both male? is this for reproduction or alpha role? was the older animal the one forcing the other away?

video 3: do animals that look similar stay together? was the horse injured?

Physiological Mechanisms




Ecology- study of interactions among organisms and their environments

Phenotypic variation in a population is due to: genotype and environment

Sometimes genetic differences among individuals have a greater influence on phenotypic variation in population, sometimes environmental differences that individuals experience have a greater influence

Heritability- the portion of phenotypic variation in a population due to genetic differences between individuals

Natural selection- one mechanism of evolution if three conditions are met THEN adaptive evolution occurs

  1. Phenotypic variation in the population
  2. Some of that variation is inherited
  3. Interaction with the environment: Traits that increase survival and reproductive of individuals increase in frequency

NATURAL SELECTION Those individuals with traits best suited for the local environment survive, grow, and leave more fertile offspring

This leads to changes in genetic makeup of a population over generations and favorable characteristics accumulate over time

Relative frequency of genes change over time

natural selection acts on individual

evolution acts on population

Why aren’t organisms perfectly adapted to their environments?

-What is “perfection”?

-Organism currently not in an environment it evolved in

-Genetic constraints and lack of genetic variation-

-Gene flow

-Ecological trade-offs