BIOL112 - Ecology (Set 4)

Lecture 24 - Life Histories

What are components of an organism’s life history?

Adaptations of organisms that influence aspects of their biology such as body size, survival, age at reproductive maturity, number of offspring it prdouces.

What are the “vital rates” that life history components determine?

Maturity (age at first reproduction), parity (number of reproduction episodes in an organism’s lifetime), fecundity (number of offspring per episode), senescence and mortality (life span and age related declines in vital rates).

What is the principle of allocation?

The idea that the amount of energy available to each organism is limited, and that when energy is allocated to one function, it reduced the energy available for other functions (trade-offs).

What is fecundity inversely related to?

The amount of parental care given to each individual offspring.

Theoretically, what would happen if there were no trade-offs? 

A Darwinian demon; a species with no physical limits that would ‘take over'.’

What are energy budgets and what do they involve?

The energy required for processes like growth, maintenance, activity, reproduction, and how said energy is allocated to each process.

What is an example of a ‘strategy’ seen in a species, where a set of life history features are correlated?

Birds with higher adult morality have higher annual fucundancy and younger age at first breeding.

(Plants) what do life-histories look like for r-selected species?

Small adults, fast population growth, short life span, high seed counts, small seeds, widespread seed dispersal.

(Plants) what do life-histories look like for k-selected species?

Large adults, slow population growth, long life span, low seed counts, large seeds, limited seed dispersal.

Why do we care about the life histories of orgnaisms?

For the conservation of species, the understanding of constraints, the modelling of population dynamics, the understanding of evolution, and much more.