Question 1

Which of the following best describes the Cambrian Explosion?

Accepted Answer

A rapid diversification of animal body plans and phyla over a relatively short geological period.

Question 2

According to the geological time scale, which period directly follows the Cambrian?

Accepted Answer

Ordovician

Question 3

What is the significance of the Burgess Shale and Chengjiang fossil deposits?

Accepted Answer

They provide a record of the morphological diversity during the Cambrian Explosion.

Question 4

Which factor is most strongly associated with the increased likelihood of species extinction according to Jablonski (1986)?

Accepted Answer

The size of the species range

Question 5

What is the minimum viable population size, as described by Dan Simberloff?

Accepted Answer

The smallest population size that can survive without risk of extinction, typically 10s-100s of individuals.

Question 6

Which of the following is a plausible cause for the Cambrian Explosion according to Knoll and Carroll (1999)?

Accepted Answer

A sudden increase in atmospheric oxygen levels.

Question 7

Which equation best represents the kinetic energy ($$KE) of $$the Chixulub asteroid, given its mass ($$m) $$and velocity ($$v$$)?

Accepted Answer

$$KE = \frac{1}{2}mv^2$

Question 8

Which statement best explains why the KT boundary is unique in terms of extinction patterns?

Accepted Answer

Species with large geographic ranges went extinct as often as those with small ranges.

Question 9

What is the background extinction rate?

Accepted Answer

The sum total of local extinction of lineages over time.

Question 10

Which of the following is NOT a factor contributing to the vulnerability of small populations to extinction?

Accepted Answer

Increased geographic range

Question 11

Which group of animals first appeared during the Cambrian period, according to fossil evidence?

Accepted Answer

Nearly all animal phyla

Question 12

Which of the following best describes mass extinction?

Accepted Answer

The sudden disappearance of a large number of species (\u003e60%) in a short period of time.

Question 13

Which evolutionary innovation is implied to be important by the pattern of animal phylogeny during the Cambrian Explosion?

Accepted Answer

Development of bilateral symmetry

Question 14

According to Van Valen (1973), the likelihood of species extinction is:

Accepted Answer

Independent of the age of the taxon.

Question 15

Which of the following is a real-world example of an extrinsic factor leading to mass extinction?

Accepted Answer

Asteroid impact at the KT boundary

Question 16

Which equation would you use to calculate the average length of a species in the geological record, given the total time span ($$T) $$and the number of species ($$N$$)?

Accepted Answer

$$	ext{Average length} = \frac{T}{N}$$

Question 17

Which of the following best explains the Red Queen dynamic in extinction theory?

Accepted Answer

Species must continuously adapt to survive against ever-changing environmental pressures.

Question 18

Which of the following is a challenge in assessing extinction risk for extant species?

Accepted Answer

Incomplete taxonomy

Question 19

Which life history trait is associated with greater extinction risk?

Accepted Answer

Specialist species with narrow ecological niches

Question 20

Which statement best summarizes the relationship between morphological diversity and lineage diversity during the Cambrian Explosion?

Accepted Answer

The Cambrian Explosion was an explosion of morphological diversity, not lineage diversity.

Lec 22

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