Evolution & Natural Selection (Deck 11)

Question 1

What is evolution in biological terms?

Answer 1

Change in heritable traits of a population across generations.

Question 2

What is natural selection?

Answer 2

A process where individuals with advantageous traits are more likely to survive and reproduce.

Question 3

Why does evolution act on populations rather than individuals?

Answer 3

Individuals do not change their genes; populations change allele frequencies over time.

Question 4

What are the four requirements for natural selection?

Answer 4

Variation, heritability, overproduction, and differential survival/reproduction.

Question 5

What is variation?

Answer 5

Differences in traits among individuals within a population.

Question 6

Why is variation essential for evolution?

Answer 6

Without variation, there is nothing for selection to act upon.

Question 7

What is heritability?

Answer 7

The ability of a trait to be passed from parents to offspring.

Question 8

What is differential reproductive success?

Answer 8

Some individuals leave more offspring than others due to trait advantages.

Question 9

What is fitness in evolutionary biology?

Answer 9

Relative reproductive success, not physical strength.

Question 10

Why is fitness context-dependent?

Answer 10

A trait’s advantage depends on the environment.

Question 11

What is adaptation?

Answer 11

A heritable trait that increases fitness in a specific environment.

Question 12

Why are adaptations not perfect?

Answer 12

They are constrained by trade-offs, history, and existing structures.

Question 13

What is mutation’s role in evolution?

Answer 13

It creates new genetic variation.

Question 14

Why are most mutations neutral or harmful?

Answer 14

Random changes are unlikely to improve function.

Question 15

How does recombination contribute to evolution?

Answer 15

It reshuffles existing variation into new combinations.

Question 16

What is genetic drift?

Answer 16

Random changes in allele frequencies due to chance.

Question 17

Why is genetic drift strongest in small populations?

Answer 17

Chance events have proportionally larger effects.

Question 18

What is a bottleneck effect?

Answer 18

Loss of genetic diversity after a population size reduction.

Question 19

What is the founder effect?

Answer 19

Reduced genetic variation when a population is started by few individuals.

Question 20

How does gene flow affect evolution?

Answer 20

Movement of alleles between populations reduces differences.

Question 21

What is sexual selection?

Answer 21

Selection based on mating success rather than survival.

Question 22

Why can sexual selection favor seemingly harmful traits?

Answer 22

Because reproductive advantage can outweigh survival cost.

Question 23

What is artificial selection?

Answer 23

Human-directed breeding for desired traits.

Question 24

How does artificial selection demonstrate evolution?

Answer 24

It shows rapid, directional trait change under selection.

Question 25

What is speciation?

Answer 25

The formation of new species.

Question 26

What is reproductive isolation?

Answer 26

Barriers preventing populations from interbreeding.

Question 27

What is allopatric speciation?

Answer 27

Speciation due to geographic separation.

Question 28

What is sympatric speciation?

Answer 28

Speciation without geographic separation.

Question 29

What are prezygotic barriers?

Answer 29

Barriers preventing mating or fertilization.

Question 30

What are postzygotic barriers?

Answer 30

Barriers producing unviable or sterile offspring.

Question 31

What is adaptive radiation?

Answer 31

Rapid diversification into many niches.

Question 32

What is convergent evolution?

Answer 32

Independent evolution of similar traits in unrelated lineages.

Question 33

What is divergent evolution?

Answer 33

Accumulation of differences from a common ancestor.

Question 34

What is homologous structure?

Answer 34

Structures with shared ancestry but possibly different function.

Question 35

What is analogous structure?

Answer 35

Structures with similar function but different ancestry.

Question 36

What is vestigial structure?

Answer 36

A reduced structure inherited from ancestors.

Question 37

Why are vestigial traits evidence of evolution?

Answer 37

They reflect historical function rather than current need.

Question 38

What is fossil evidence?

Answer 38

Preserved remains showing change over time.

Question 39

Why is the fossil record incomplete?

Answer 39

Fossilization is rare and biased.

Question 40

What is molecular evidence for evolution?

Answer 40

DNA and protein similarities across species.

Question 41

Why does DNA similarity indicate common ancestry?

Answer 41

More similar sequences imply recent shared ancestry.

Question 42

What is a phylogenetic tree?

Answer 42

A diagram showing evolutionary relationships.

Question 43

What does a node represent on a phylogenetic tree?

Answer 43

A common ancestor.

Question 44

Why are evolutionary trees hypotheses?

Answer 44

They are based on best available evidence and revised with new data.

Question 45

What is gradualism?

Answer 45

Evolution occurring slowly over long periods.

Question 46

What is punctuated equilibrium?

Answer 46

Long stability interrupted by rapid change.

Question 47

Are gradualism and punctuated equilibrium contradictory?

Answer 47

No, both patterns are observed.

Question 48

Why is evolution not goal-directed?

Answer 48

It has no foresight; selection acts only on current conditions.

Question 49

Why does evolution not produce 'progress'?

Answer 49

Fitness is environment-specific, not hierarchical.

Question 50

What is coevolution?

Answer 50

Reciprocal evolutionary change between interacting species.

Question 51

How do predators and prey coevolve?

Answer 51

Adaptations in one drive counter-adaptations in the other.

Question 52

What is antibiotic resistance evolutionarily?

Answer 52

Rapid selection for resistant variants.

Question 53

Why is evolution observable in real time?

Answer 53

Short generation times allow rapid change.

Question 54

Why does evolution not violate thermodynamics?

Answer 54

It increases local order using external energy.

Question 55

Why is evolution compatible with genetics?

Answer 55

Genes provide the heritable variation selection acts on.

Question 56

What is the difference between evolution and origin of life?

Answer 56

Evolution explains change after life exists, not how life began.

Question 57

Why is 'survival of the fittest' misleading?

Answer 57

It oversimplifies fitness as strength instead of reproduction.

Question 58

Why do misconceptions about evolution persist?

Answer 58

It conflicts with intuition and is often misrepresented.

Question 59

How does evolution unify biology?

Answer 59

It explains patterns across genetics, anatomy, ecology, and fossils.

Question 60

What is microevolution?

Answer 60

Small-scale changes in allele frequencies.

Question 61

What is macroevolution?

Answer 61

Large-scale evolutionary change over long times.

Question 62

Why are micro- and macroevolution connected?

Answer 62

Macroevolution is accumulated microevolution.

Question 63

What role does chance play in evolution?

Answer 63

Mutation and drift introduce randomness.

Question 64

What role does necessity play in evolution?

Answer 64

Selection filters variation non-randomly.

Question 65

Why is evolution essential for medicine?

Answer 65

It explains resistance, virulence, and disease dynamics.

Question 66

If teaching evolution in one sentence, what’s the key idea?

Answer 66

Evolution is the change in populations over time driven by variation, selection, and chance.