3T03 Midterm 1 Content (Flashcard)

Proximate Cause Questions

Questions addressing the immediate mechanisms or processes behind behavior, including physiological and cognitive factors.

Ultimate Cause Questions

Questions addressing the long-term evolutionary reasons for behavior, including fitness effects and evolutionary origins.

Niko Tinbergen's four questions

A framework to study behavior encompassing mechanism, ontogeny, function, and phylogeny.

Function/ Adaptive Significance (Tinbergen’s question)

How does the behaviour contribute to survival and reproduction

Phylogeny (Tinbergen’s question)

How did the behaviour first evolve? What are its antecedents?

Optimality Theory

A framework assessing how behaviours evolve to maximize benefits while minimizing costs.

Hawk-Dove Game

A model explaining competition strategies among animals, where 'hawks' fight for resources and 'doves' avoid conflict.

Nash Equilibrium

A situation in game theory where no player can benefit by changing strategies if others keep their strategies the same.

Sexual Selection

A form of natural selection where individuals with certain traits are more attractive to potential mates.

Anisogamy

The condition of having gametes of different sizes, typically involving larger eggs and smaller sperm.

Bateman's Principle

The observation that males’ reproduction is usually limited by the number of females, whereas female reproduction is limited by the number and quality of eggs, which is resource limited

Cryptic Female Choice

A form of female choice in which females can influence the fertilization success post-copulation, like in chickens’ differential sperm ejection

Local Mate Competition

A situation in which the sex ratio is skewed towards the less competitive sex due to competition among relatives, like in fig wasps

Trivers-Willard Hypothesis

The hypothesis that parents will preferentially invest in offspring of the sex that is advantageous based on their own condition.

Sex Ratio Distorters

Heritable elements that manipulate the sex ratio of host individuals to benefit their own reproductive success.

Sperm Competition

The competition between sperm from multiple males to fertilize a female's eggs, influencing sperm allocation strategies.

Mating Guarding

A male behavioural strategy to stay close to a female to prevent other males from mating with her.

Courtship Feeding

A behavior where males provide food to females to increase their chances of mating, like hawks or spermatophores

Operational Sex Ratio (OSR)

The ratio of sexually receptive males to females in a population at a given time.

Alternative Reproductive Tactics (ARTs)

Different methods employed by individuals of the same sex to reproduce successfully, such as sneaking or displaying. Must have discontinuous distribution

Frequency Dependent Selection

A selection process where the fitness of a phenotype depends on its frequency relative to other phenotypes in the population. When balanced, they get equal lifetime reproductive success.

Condition Dependent Selection

Despite the same genetic architecture, tactics adopted by individuals differ due to diverging conditions. One tactic leads to greater reproductive success and is preferred, but playing it successfully is somehow more demanding, such that only some individuals can pull it off. Tactics may be plastic throughout lifetime, or may be fixed

Polyandry

A mating system in which a female has multiple male partners.

Polygynous

A mating system in which a male has multiple female partners.

Sexual Dimorphism

Distinct differences in size or appearance between the sexes of the same species, often influenced by sexual selection.

Ejaculate Expenditure

The strategic allocation of sperm by males in response to competition levels.

Sexual Selection

A process whereby secondary sexual traits become elaborated because they increase their owner’s ability to gain access to mates

Sperm Morphology

Head contains DNA, mid-piece contains fuel and tail affects speed

Long-tailed Sperm

Increases the speed of sperm, present when sperm competition is heightened

Resource Holding Power (RHP)

An individual's ability to win contests and maintain control over resources based on size, strength, and weaponry.

Mating Plugs

Gelatinous substances deposited by males in females' reproductive tracts to block further matings.

Sneaker Males

Males that employ stealthy strategies to mate with females, often circumventing dominant males.

Humans as Sperm Competitors

Research indicating that human males can adjust sperm motility and quantity based on perceived competition.

Direct Benefits of Mate Choice

Immediate advantages granted to females by choosing mates with better resources or parental abilities, such as food and territory, or parental care

Indirect Benefits of Mate Choice

Long-term advantages associated with genetic quality of chosen mates, directly influencing offspring quality

Costly Signals

Traits that provide reliable indications of fitness, developed through evolutionary pressure, typically in mate choice.

Strategic Sperm Allocation

Males adjusting their sperm investment based on competition levels or mating cues.

Cuckoldry

A mating strategy where male competitors sneak copulations with females mated to other males.

Bowerbird Courtship

A display behaviour where males build and decorate structures to attract females; display intensity increases courtship success

Natural Selection vs. Sexual Selection

Natural selection relates to survival, while sexual selection involves traits that enhance mating success.

Co-evolution

The evolution of two or more species in response to each other over time.

Red Queen Hypothesis

The idea that species must constantly adapt and evolve not just for reproductive advantage but also for survival against evolving enemies.

Marine Isopod Reproductive Strategies

Three distinct strategies: alpha (large, hold territory), gamma (tiny, stealth) and beta (female mimic)

Intrasexual Selection

Competition among individuals of the same sex for access to mates.

Intersexual Selection

Selection based on the preferences of one sex for certain traits in the opposite sex.

Ritualized Fighting

Non-lethal displays of aggression aimed at establishing dominance without physical conflict, to minimize risk. Includes assessment tactics, threat displays, non-contact behaviour.

Balancing Selection

A type of natural selection that maintains genetic diversity in a population.

Sex Role Reversal

A mating system where traditional gender roles are reversed, and females compete for males.

Resource Competition

Competition among individuals for limited resources essential for survival.

Sperm Competition Theories

Higher sperm competition is present when females multiply mate. Can be associate with longer sperm tails, larger testes, more motile sperm.

Fisher's Sex Ratio Principle

The idea that natural selection favours a 1:1 sex ratio at birth due to equal reproductive strategies, due to it being an ESS

Hymenoptera’s Haplodiploidy

A sex-determination system in which fertilized eggs develop into females and unfertilized ones into males.

Social Hierarchy in Mating

The effects of dominance and subordination on reproductive access and success.

Developmental Windows in Song Learning

Critical periods during which young birds must learn songs to develop their vocal abilities.

Sperm Competition Dynamics

Interactions occurring post-copulation between sperm from different males.

Nutritional Influences on Reproductive Success

The effect of dietary factors on the reproductive outcomes of males and females.

Post-Copulatory Control Mechanisms

Female strategies to influence the success of sperm from different males after mating.

Sexual Coercion

The exertion of pressure or force by one sexual partner over another in the context of mating.