Fecundity: The amount of offspring an animal has during its life
Life history: Traits that determine timing and details of reproduction and death. Tend to be population specific rather than species specific. In a way each population makes its own phenotypes which determine reproductive success. Explains organism size, maturation rate, how many offspring they have, and how long they live. Examples of traits include:
Birth size: What is the mass at birth
Growth rate: How fast do they mature
Age at maturity: When are they fully matured, a number is favored that outputs the most offspring within a given lifetime
Reproductive investment
Mortality rates: How often do they die
Ideal organism: Would reproduce right after birth, has may offspring that it protects, and does this repeatedly in a long life. It outcompetes all other species, avoids predators, and catches all prey.
Trade offs: Decisions made by a species relevant to life history, for example more babies means they will be smaller. Long life means a longer maturation rate.
C=(R+A)+(F+U)+B+G) is the balanced equation for the energy budget of an organism. This is what inevitably causes a species to evolve, to occupy a niche or set of conditions with energy allocated accordingly
Principal of allocation: Something within the energy budget must lose out
Extrinsic factors: Things that effect how a species balances its energy budget that come from outside itself. Environmental factors, like predators and available food
Intrinsic factors: Things that effect how a species balances its energy budget that come from itself. Includes physiology, genetics, when they are born/die, if they reproduce early because they die young etc.
Semelparity: The organism will reproduce once, and then die (all eggs in one basket, literally)
Iteroparity: The organism will reproduce several times and them die. This is much more common than semelparity
Lack’s Hypothesis: Clutch size of eggs for a given species will be determined by the amount of energy that can be dedicated to protecting them, but also maximizing the amount of eggs that will survive. Too many means the energy has to be subdivided too much and reduces overall survival rate.
Altricial: Offspring that are born helpless, they are born earlier and smaller, requiring more energy after born
Precocial: Offspring that are born advanced, can somewhat care for themselves. These tend to be bigger offspring, but they are more functional after birth. More energy is used up front, leading to less parental care.
r-selected species: Life history is dominated by intrinsic rates of increase, they reach maturity quickly, have a high fecundity, and produce many small offspring. Generations are short, offspring have little parental care
K-selected species: Life history is dominated more by resources and competitive advantages. They mature later in life, are larger, have fewer offspring, and have larger offspring. There is more parental care, and they reproduce later in life
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