Question 1

Which of the following best describes adaptive radiation?

Accepted Answer

The rapid evolution of many new species from a common ancestor due to the sudden availability of ecological niches.

Question 2

What is a key factor that often triggers adaptive radiation on islands?

Accepted Answer

Sudden opening of ecological niches due to lack of competition and new resources.

Question 3

Which prediction is supported by the dispersal and colonization hypothesis for Hawaiian Drosophila?

Accepted Answer

Closely-related species should be found on adjacent islands, and older islands should have older species.

Question 4

Which equation best represents the founder effect speciation scenario?

Accepted Answer

$$ N_e = \frac{4N_mN_f}{N_m + N_f} $$

Question 5

Why are rates of endemism higher on islands that are farther from the mainland?

Accepted Answer

Because isolation increases the likelihood of speciation and reduces gene flow from the mainland.

Question 6

Which of the following is an example of a key innovation in adaptive radiation?

Accepted Answer

The evolution of olfactory receptor genes in Hawaiian Drosophila allowing them to exploit new host plants.

Question 7

In the context of adaptive radiation, what does 'ecological opportunity' refer to?

Accepted Answer

The availability of ecologically accessible resources that can be evolutionarily exploited.

Question 8

Which macroevolutionary pattern is observed in Anolis lizards on Caribbean islands?

Accepted Answer

Ecomorphs generally evolve once on each island and occupy unique niches, preventing similar ecomorphs from evolving.

Question 9

Losos et al. seeded depauperate islands with Anolis lizards. After ten years, what evolutionary change was observed?

Accepted Answer

The lizards evolved longer hind limbs in response to wider perch diameters, demonstrating adaptation to new environments.

Question 10

Which equation best describes the positive correlation between hind limb length and perch diameter in Anolis lizards?

Accepted Answer

$$ y = mx + b $$

Question 11

What is the significance of molecular phylogenetic studies in understanding adaptive radiation?

Accepted Answer

They reveal patterns of divergence and relationships among species, supporting hypotheses about colonization and speciation.

Question 12

Which scenario best illustrates the concept of founder effect speciation?

Accepted Answer

A small population or a single gravid female colonizes a new island, leading to immediate isolation and rapid speciation.

Question 13

Which of the following is NOT a characteristic of adaptive radiation?

Accepted Answer

Evolution of a single species with no change in morphology or physiology.

Question 14

What is the relationship between island age and species diversity in Hawaiian Drosophila?

Accepted Answer

Older islands have older species, and closely-related species are found on adjacent islands.

Question 15

Which of the following best explains the diversification of cichlid fish in African Rift lakes?

Accepted Answer

Adaptation to empty niches, radiation of morphology due to key innovations, and diversification of male color patterns.

Question 16

Which term describes the evolution of phenotypically and reproductively distinct species in a clade?

Accepted Answer

Diversification

Question 17

What is the primary mechanism by which Hawaiian silverswords radiated into diverse forms?

Accepted Answer

Adaptive radiation following colonization and exploitation of new ecological niches.

Question 18

Which equation would you use to estimate the rate of speciation following an extinction event?

Accepted Answer

$$ r = \frac{N_{final} - N_{initial}}{t} $$

Question 19

Which of the following is a plausible outcome of adaptive radiation after a mass extinction event?

Accepted Answer

Rapid diversification of surviving lineages into newly available ecological niches.

Question 20

Which real-world example best illustrates adaptive radiation?

Accepted Answer

The diversification of Hawaiian drosophilid flies into over 1000 endemic species.

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Study Guide - Practice Questions