POPULATION ECOLOGY - Population Responses to Environmental Changes

FITNESS

number of offspring that organisms with a particular genotype or phenotype leave behind, on average, as compared to others

FITNESS

a measure of how well organisms survive and reproduce, with emphasis on "reproduce."

FITNESS

describes how good a particular genotype is at leaving offspring in the next generation relative to other genotypes

• about success at surviving and reproducing, not about exercise and strength

Adaptiveness

a biological characteristic with a heritable basis that improves reproduction and/or survival and results from evolution by natural selection.

Reproductive success

_______________ – the production of independent offspring per breeding attempt or lifetime

Persistence

_________________ – the probability of leaving descendants over long periods of time

PHENOTYPIC PLASTICITY

capacity of the same organisms to exhibit different characteristics or phenotypes (behavior, physiology, or morphology) under varied environmental conditions

PHENOTYPIC PLASTICITY

environment-dependent expression of phenotypes by genotypes

• might help or might hinder both immediate survival and future adaptation

SPECIES RANGE SHIFT

changes of the distribution limits of a species, generally along altitudinal or latitudinal gradients (Doak and Morris, 2010)

• species migrations

SPECIES RANGE SHIFT

does not guarantee species survival, but minimally a range shift can be expected to delay the consequences of long-term directional climate change.

SPECIES RANGE SHIFT

human-induced habitat loss and fragmentation constrains the range of many species, making them unable to respond to climate change by moving

Phenology

_____________ – the timings of cyclical or seasonal biological events, such as migrations, egg laying, flowering, and hibernation.

Phenological range shift

Many species have life cycle events that are influenced by climatic factors

• e.g. barnacle goose populations travel between their breeding and overwintering grounds in the spring and fall