Week 2

Question 1

Ultimate Level of Analysis

Answer 1

Explains why a behavior or trait evolved (its survival or reproduction purpose).

Question 2

Proximate Level of Analysis

Answer 2

Explains how a behavior or trait works (biological or environmental mechanisms).

Question 3

Cruel Step Parent Effect

Answer 3

stepparents are statistically more likely to abuse or mistreat their stepchildren compared to biological parents

Question 4

Tinbergen’s Four Questions:
Ontogeny

Answer 4

How a behaviour develops within an individual

(development)

Question 5

Tinbergen’s Four Questions:
Mechanism

Answer 5

The physiological or neural processes causing the behaviour

(causation)

Question 6

Tinbergen’s Four Questions:
Phylogeny

Answer 6

How the behaviour evolved over generations

(evolution)

Question 7

Tinbergen’s Four Questions:
Function

Answer 7

The adaptive purpose of the behaviour

Question 8

Directional Selection

Answer 8

Favors one extreme of a trait, shifting the population’s average

For example, if in a population of birds, birds with larger beaks are better at getting food during a drought, then over time, the population will have more birds with larger beaks, as they are more likely to survive and reproduce. The “direction” of the selection is toward larger beaks.

Question 9

Stabilizing Selection

Answer 9

favors the average or middle range of a trait and selects against the extremes.

Question 10

Disruptive Selection

Answer 10

favors both extremes of a trait, while selecting against the average or intermediate traits.

Question 11

Purifying Selection (negative selection)

Answer 11

harmful traits or mutations are removed from a population because they reduce survival.

Question 12

Balancing Selection

Answer 12

a natural selection process that maintains genetic diversity in a population

Question 13

Allopatric Speciation

Answer 13

This type of speciation happens when a population is physically separated by a geographic barrier, like a mountain, river, or ocean. Over time, the isolated populations evolve independently and can become different species because they no longer interact or interbreed.

Question 14

Sympatric Speciation

Answer 14

This occurs when a new species evolves within the same geographic area as the original population. There is no physical barrier; instead, reproductive isolation can happen due to behavioral, ecological, or genetic differences. For example, two groups of animals might start mating at different times or prefer different food sources, leading them to evolve separately.

Question 15

Adaptive Radiation

Answer 15

Adaptive radiation is the process where a single species rapidly evolves into many different species, each adapted to a different environment or ecological niche. This typically happens when a species colonizes a new area with many different habitats, leading to variations in traits that are favorable for survival in those specific environments.

Question 16

Darwin’s Finches

Answer 16

These are a famous example of adaptive radiation. Darwin observed on the Galápagos Islands that finches from a common ancestor evolved into several species with different beak shapes and sizes. Each beak was adapted to a specific type of food available on different islands, such as seeds, insects, or even cactus flowers. This helped Darwin understand how species can rapidly diversify to fill different ecological roles.

Question 17

Intrasexual Selection: Scramble

Answer 17

a mating system where males compete for females by searching widely and quickly to find as many mating opportunities as possible.

Question 18

Intrasexual Selection: Endurance Rivalry

Answer 18

Ability to remain reproductively active for long portion of breeding season

Question 19

Maladaptive Traits

Answer 19

Traits that reduce survival or reproduction

Question 20

Neutral Traits

Answer 20

Traits with no effect on survival or reproduction.

Question 21

Exaptation

Answer 21

when a trait or feature of an organism or culture shifts its function over time

Question 22

Adaptation

Answer 22

the process by which animals adjust to their environment to survive, and evolution is the result of this process over time

Question 23

heterozygote advantage

Answer 23

Having two different gene versions (alleles) is better for survival than having two of the same.

Question 24

Panglossian view

Answer 24

The idea that all traits or behaviors in organisms are optimal and evolved specifically to serve a purpose, implying that everything in nature is perfectly adapted. This view is often critiqued because some traits may arise due to chance, genetic drift, or constraints, rather than being perfectly optimized by natural selection.

Question 25

linkage

Answer 25

When genes are located close together on the same chromosome, they are often inherited together, which can result in traits being passed on even if they are not beneficial.

Question 26

Neutral Theory

Answer 26

Most genetic mutations have no effect on an organism’s fitness (they are neither helpful nor harmful).

Question 27

Psychological Constraint

Answer 27

A limitation on an organism’s behavior or mental processes due to how their brain or cognition evolved over time. These constraints may prevent certain behaviors, even if they would be beneficial.

Question 28

Comparative methods

Answer 28

Compare traits of living species to their family tree.

Question 29

Computational models

Answer 29

Make predictions and test them using real species.

Question 30

Genetic approaches

Answer 30

Study genes to understand traits and find selection markers

Question 31

Cross-cultural research

Answer 31

Study traits that might be the same across all cultures to see if they're adaptations.

Question 32

Evolutionary Arms Race

Answer 32

A co-evolutionary process where species develop counter-adaptations against each other (e.g., cheetahs and gazelles evolving faster speeds).