Ecological Life History and Population Properties

Vocabulary flashcards covering key terms in animal adaptations, life history strategies, plant and animal reproduction, mating systems, population properties, distribution patterns, sampling techniques, and demography.

Scaling

Predictable changes in morphological or physiological features as body size changes.

Surface area : volume ratio (SA:V)

Amount of surface area relative to body volume. As an organism gets larger, $SA:V$ decreases.

Gas exchange

Movement of $O_2$ and $CO_2$ between an organism and its environment.

Homeostasis

Maintaining a relatively constant internal environment.

Conformer

Organism whose internal conditions change as external environmental conditions change.

Regulator

Organism that maintains internal conditions within a relatively narrow range despite external changes.

Negative feedback

Response that reverses a change and returns the system toward its set point.

Positive feedback

Response that reinforces/amplifies the original change.

Set point

Target or normal condition around which a regulated system operates.

Homeotherm

Organism that maintains a relatively constant body temperature.

Poikilotherm

Organism whose body temperature varies substantially.

Endotherm

Organism that gets most body heat from internally generated metabolic heat.

Ectotherm

Organism that relies mainly on environmental sources of heat.

Metabolic rate

Amount of energy expended by an animal over a specific period of time.

Cellular respiration

Process that uses glucose and $O_2$ to produce usable energy; also releases heat.

Adaptation

Inherited trait produced through natural selection that increases fitness in a particular environment.

Acclimation

Reversible physiological adjustment by an individual to environmental change.

Allen's rule

Observation that animals adapted to colder climates tend to have shorter/thicker appendages than animals adapted to warmer climates.

Supercooling

Lowering body temperature below the freezing point without actually freezing.

Countercurrent heat exchange

Arrangement of arteries and veins that transfers heat between blood flows; can conserve or dissipate heat.

Life history

Organism's lifetime pattern of growth, development, reproduction, and death.

Life cycle

Specific series of changes in an organism's form, often divided into stages.

Life-history trait

Characteristic involving the timing or occurrence of life stages, such as age at maturity, offspring number, growth rate, or lifespan.

Fitness

Genetic contribution an individual makes to future generations.

Trade-off

Principle that increasing investment in one biological function means less energy/resources are available for another.

Fecundity

Number of offspring produced per unit of time.

Age at maturity

Age at which an organism becomes reproductively mature.

Parental care

Investment by parents that increases offspring survival, usually at some cost to the parents.

Altricial

Condition in which young are born/hatch relatively helpless and require substantial parental care.

Precocial

Condition in which young are relatively developed and mobile at birth/hatching.

Asexual reproduction

Offspring produced without egg-sperm fusion.

Division

Form of asexual reproduction where an organism divides to form offspring.

Budding

Form of asexual reproduction where a new individual grows from part of the parent.

Propagation

Form of asexual reproduction where new plants are produced vegetatively.

Parthenogenesis

Form of asexual reproduction where offspring develops from an unfertilized egg.

Sexual reproduction

Reproduction involving fusion of gametes.

Stamen

Pollen-producing/male portion of flower.

Pistil

Ovule-producing/female portion of flower.

Dioecious

Condition where male and female reproductive structures occur on different individuals.

Hermaphroditic

Condition where an individual possesses both male and female reproductive organs.

Monoecious

Condition where an individual plant produces both male and female flowers.

Perfect flower

Flower that contains both male and female reproductive structures.

Imperfect flower

Flower that contains only male OR female reproductive structures.

Simultaneous hermaphrodite

Individual that functions as both sexes at the same time.

Sequential hermaphrodite

Individual that changes sex during its lifetime.

Mating system

Pattern through which sexually reproducing organisms obtain mates.

Sexual selection

Selection arising from differences in mating/reproductive success.

Monogamy

Pair bond between one male and one female.

Seasonal monogamy

Monogamous bond maintained for a breeding season.

Sequential monogamy

Condition in which individuals have different monogamous partners over time.

Extra-pair copulation

Mating outside an established pair bond.

Polygamy

Condition in which one individual has multiple pair bonds.

Polygyny

Mating system involving one male and multiple females.

Polyandry

Mating system involving one female and multiple males.

Promiscuity

Mating system with no lasting pair bonds.

Polygyny threshold

Point at which a female may gain greater reproductive benefit by mating with an already-paired male than an unpaired male.

Iteroparity

Reproductive strategy of reproducing multiple times during a lifetime.

Semelparity

Reproductive strategy of reproducing once during a lifetime.

r-selected species

Species adapted to variable/short-lived environments, characterized by small body, early maturity, high fecundity, many small offspring, lower offspring survival, short lifespan, and little parental care.

K-selected species

Species adapted to stable/long-lived environments, characterized by larger body, later maturity, low fecundity, few large offspring, higher offspring survival, longer lifespan, and high parental care.

Population

Individuals of the same species inhabiting a given area.

Population structure

Characteristics such as density, age/size classes, and geographic spacing.

Demography

Study of the size, composition, distribution, and changes of populations.

Population size (N)

Total number of individuals in a population.

Abundance

Total number of individuals in a population.

Population density

Number of individuals per unit area.

Ecological density

Individuals per unit of suitable/available living habitat, rather than total area.

Age structure

Relative numbers of individuals in different age classes.

Size structure

Distribution of individuals among size classes.

Stage structure

Population divided by biological stages such as juvenile and adult.

Distribution

Spatial location or area occupied by a population.

Geographic range

Total area encompassing all individuals of a species.

Ubiquitous

Refers to a species with a wide geographic range.

Endemic

Refers to a species restricted to a particular geographic range.

Limiting factor

Environmental condition that restricts where a species can occur.

Microclimate

Local climatic conditions that differ from the broader surrounding climate.

Metapopulation

Collection of local subpopulations connected by dispersal.

Random distribution

Spatial arrangement where individuals occur independently/unpredictably.

Uniform distribution

Spatial arrangement where individuals are spaced relatively evenly.

Clumped distribution

Spatial arrangement where individuals occur in groups; the most common distribution pattern.

Census

Counting every individual; practical mainly for small or compact populations.

Systematic sampling

Estimating population properties by collecting samples according to a defined method.

Quadrat

Fixed sampling area used to estimate density, especially for plants and sessile organisms.

Sessile

Fixed in one place/nonmobile.

Mark-recapture

Method to capture organisms, mark them, release them, then sample again to estimate population size.

Lincoln-Petersen index

Mathematical method for estimating population size from mark-recapture data.

Dispersal

Movement away from the population of origin.

Emigration

Permanent movement out of a population.

Immigration

Permanent movement into a population.

Migration

Regular, often daily or seasonal, movement between habitats or regions.

Diel migration

Daily movement, often associated with day/night cycles.

Diel vertical migration

Daily movement up and down through the water column.

Active dispersal

Movement where an organism moves using its own energy.

Passive dispersal

Movement where an organism is transported by another force, such as wind, water, or another organism.

Birth rate

Rate at which new individuals are produced.

Death rate

Rate at which individuals die; also known as mortality rate.

Natality

Production of new individuals through birth/reproduction.

Mortality

Death of individuals.

Open population

Population in which births, deaths, immigration, and emigration can change population size.

Closed population

Population with no immigration or emigration; changes only through births and deaths.