3T03 Midterm 1 Content (Q&A)

What are the two main types of questions addressed in behavioral studies according to levels of analysis?

Proximate and ultimate cause questions.

What type of question is concerned with 'how' something occurs?

Proximate cause questions.

What type of question is concerned with 'why' a behavior occurs?

Ultimate cause questions.

What are Niko Tinbergen's four questions that explain behavior?

Mechanism, Ontogeny, Phylogeny, and Function.

What is the function of birds singing in relation to fitness?

Attracting mates and deterring competitors.

What is meant by 'optimality' in behavioral ecology?

Minimizing costs while maximizing benefits in behavior.

What is an evolutionary stable strategy (ESS)?

A strategy that, if adopted by most members of a population, cannot be invaded by any alternative strategy.

What is Bateman's Principle?

Males have higher variance in reproductive success compared to females, so their reproductive success increases more with multiple mating

What is the difference between intrasexual and intersexual selection?

Intrasexual selection involves competition within one sex, while intersexual selection involves mate choice between sexes.

What is the primary hypothesis regarding why sex evolved? 2

To clear deleterious mutations and create genetic diversity, through genetic recombination

What are the potential costs of sexual reproduction? 4

Breaking up co-adapted gene complexes, the cost of males, disease transmission, and energy expenditures for finding mates.

What is the Fisher's Sex Ratio Principle?

The idea that parents will tend to produce offspring in a 1:1 sex ratio to maximize reproductive success.

What is cryptic female choice?

The ability of females to influence fertilization success through behaviours such as selective sperm ejection.

In the context of sperm competition, what is a mating plug?

A gelatinous material that hardens in the female reproductive tract to maximize chances of fertilization.

What role does nutrient availability play in maternal sex ratio biases?

Nutritional stress can lead to biased sex ratios, with lower conditions favoring the sex with lower reproductive variability

Why might males of some species choose to mate with females from a distance rather than compete directly?

To avoid the costs associated with fighting and to maximize mating opportunities.

What is the role of the operational sex ratio (OSR) in sexual selection?

It determines the ratio of sexually active males to females, influencing mating competition.

How can mate choice theory benefit female reproductive success?

By selecting males that provide direct benefits, such as resources or parental care.

What is the advantage of having larger testes in some species?

It increases the likelihood of successful fertilization in high sperm competition environments.

In the round goby, what are the two male phenotypes and their reproductive approaches?

Guarder males, who are larger and provide parental care, and sneaker males, who are smaller and attempt to mate unnoticed.

How does proximity to resources impact sex allocation in species such as the Seychelles warbler?

It influences the ratio of sons to daughters based on the quality of the territory. Poor quality terriitories have mostly sons (77%) whereas high quality territories can support more daughters (become helpers in adulthood)

What mating tactic do sneaker males commonly employ?

Cuckholding, where they mate quickly while guarding males are occupied.

What is the difference between a strategy and a tactic?

A strategy is genetically determined i.e. you have the genes to be big or small. Vs a tactic is a behaviour, which may result from a strategy, such as is you are big then you fight, if you are small then you sneak or mimic.

What is alternative reproductive tactics (ARTs) in the context of sexual selection?

Different tactics employed by males to secure mating opportunities, such as guarding, sneaking, or mimicking.

What male traits are often selected through intrasexual competition? 3

Size, strength, and weaponry

How does frequency dependent selection relate to reproductive tactics?

The fitness of a reproductive tactic can increase or decrease depending on its prevalence within the population.

Why are sneaky mating tactics effective in some fish species?

They exploit opportunities to mate while avoiding confrontation with larger males.

What influences the evolution of anisogamy?

The trade-off between gamete size and quantity leading to the differentiation of male and female reproductive strategies.

What are the possible results of the Trivers-Willard hypothesis regarding offspring sex ratios?

Parents in good condition may produce more males, and those in poor condition may favor producing females.

What happens in species exhibiting local resource competition?

An imbalance in sex ratios can occur favoring the sex that experiences less competition for resources.

What are the trade-offs involved in parental investment strategies?

Investing in quality versus quantity of offspring and the associated resource allocation.

Under what circumstances might males adopt a sneaky mating tactic over a guarding strategy?

When they are smaller or if there is a higher risk of direct competition.

How can maternal condition impact reproductive success in species like red deer?

Higher maternal condition can yield healthier offspring with a greater likelihood of reproductive success.