Behavior

Vocabulary:

• Proximate causation: An explanation of behavior, based on immediate causation (example, someone runs at you with a knife at you so you run away, or zebras run from lions because of an alarm call), why an organism does a behavior

• Ultimate causation: An evolutionary approach to explain behavior, why proximate mechanisms occur and why based on fitness that organisms respond as they do (example, people with knives tend to stab others who they run at, or if zebras don’t run from lions they may get eaten). This is build up over generations, how behaviors evolve

• Reproduction: A driver of behavior, proximate and ultimate. Natural selection maximizes reproductive success, both physical and behavioral, and passes on those selected genes. Behaviorally, for a gene to be passed on this way it must already be in the population and it must be heritable. Some confer more reproductive success than others.

• Fighting: A driver of behavior, proximate and ultimate. Typically within a species to move reproduction forward. This is to gain territory and resources as well

• Migration: A driver of behavior, moving to reproduce. happens seasonally, salmon and butterflies do this

• Heritability: Calculated by the formula h²=Vg/Vp, divides genetic variance by phenotypic variance

• Fitness: How many genes are passed on by an individual

• Fitness value: Calculated by Fitness*gene frequency G1=gene frequency G2, where G is a generation. A value of 1 means the individual is contributing an equal amount of genes as they have themselves, equality between generations. >1 means the frequency is increasing, while <1 means it is decreasing. 0 means there were no offspring.

• Inclusive fitness: Reproduction of individuals and their relatives, due to relatives having some of the same genes. This is why species protect family members, they share genes so if the family lives they are more likely to increase the fitness value of their genes in the next generation

• Kin selection: When an organism helps a relative mate, or survive to mate, to increase inclusive fitness

• Coefficient of genetic relatedness: The probability that a particular allele, present in one individual is also present in another individual because of their descent from a common ancestor. The closer the relative the more important they are to protect because they share more genes, all to increase inclusive fitness, 0.5 from generation to generation

• Hamilton’s Equation: Solves for the fitness of a given behavior, W=d+sum(i*r), where W is the fitness of a given behavior, d is the direct effect of the behavior on the individual, i is the indirect effect of the behavior on the kin of the individual, and r is the coefficient of relatedness. Does the benefit outweigh the cost? Example, of 4 prarie dogs who shared 0.5 genes, one sacrified themself for the other 3 and died. So d here is -1, and i*r is 0.5 for each

• Sex: Categorized biologically by gamete type, chromosomal inheritance, morphology, and behavior. The media tends to use morphology and behavior more. All three come into effect and can be inconsistent between individuals and populations

• Sexual selection: Non-random mating, there is unequal investment from females into reproduction

• Intersexual selection: A form of sexual selection where most of the time a female chooses a mate based on secondary sexual characteristics. Hypothetically, large antlers mean they are stronger as they can carry them, and also they could defend them in a fight if needed

• Operational sex ratio: The ration of sexually competing males to sexually competing females, there are typically more males than females