Quizzes

Question 1

Skeletal growth in living mammals is considered to be _1____, with most limb bones composed of a shaft or __2___ and an articular surface or __3___

Answer 1

1. Determinate 2. Diaphysis 3. Epiphysis

Question 2

List 4 kinds of intraspecific (within species) variation requiring the examination of more than one specimen of a given species

Answer 2

Sexual, ontogenetic (age/developmental), geographic, genetic, temporal, etc.

Question 3

The dentition of living mammals is generally characterized as being

Answer 3

Heterodont and Diphyodont

Question 4

The lower jaw (mandible) of all living adult mammals is composed of a

Answer 4

Pair of bones

Question 5

The three inner ear ossicles of living mammals originate—evolutionarily and developmentally on the

Answer 5

Mandible

Question 6

Hair is generally composed of _ layers

Answer 6

3

Question 7

The correct term for a coat of hair is

Answer 7

Pelage

Question 8

List 3 taxa that comprise a monophyletic group:

Answer 8

(guinea pig, mouse, rat) or (macaque, human, chimp) or (tenrec, armadillo, elephant)

Question 9

What is the closest living relative of the Guinea pig?

Answer 9

The clade including rat and mouse

Question 10

How long ago did tenrecs and elephants share a common ancestor?

Answer 10

79.7 Million Years Ago

Question 11

Are galagos, humans, and chimpanzees monophyletic? Why or Why not?

Answer 11

No. Not all descendants of their MRCA are included (=macaque)

Question 12

On the figure itself, draw a box or circle around any 5 taxa that make up a monophyletic group.

Answer 12

Question 13

What are two purported advantages of a bony secondary palate?

Answer 13

• More efficient airflow
• Allows simultaneous running and chewing
• facilitates suckling

Question 14

Bending side to side while holding your breath

Answer 14

What I was hoping people would notice (and about 1/3rd of the class did) was that when you bend this way—which is the way a lizard bends when walking/running—air is forced in and out of your lungs. By evolving a more upright posture (and commensurate limitation of limb movement [while running] to fore-and-aft rather than side-to-side), and a muscular diaphragm, mammals became far better at separating breathing from locomotion.

Question 15

Refer to Figure 2-1 in your textbook. By your instructor’s count, there are four errors or inaccuracies in its caption (hint: there is nothing wrong with the tree itself or any of the labels). With reference to what you learned in the systematics lectures, identify any two and briefly describe why they are problematic

Answer 15

Neither “Tetrapods” nor “Amniotes” should be capitalized (first sentence), and in the third sentence, “more primitive” and “more derived” are misused in this context; by removing them entirely, the sentence is rendered perfectly accurate and acceptable. Several answered that labelled nodes are not clades, but that is incorrect. Clades can be labelled at the nodes (and, in fact, this is a more unambiguous way to identify/label monophyletic groups). However, I can understand the confusion and no points were deducted THIS TIME.

Question 16

Are the wings of bats, birds, and pterosaurs homologous? Why or why not?

Answer 16

As wings, no. The common ancestor of all three did not possess wings. But the bones comprising the wings of all three ARE homologous (as are many muscles).

Question 17

Hair is considered a ______ of mammals, but a(n) ______ of bats.

Answer 17

synapomorphy, symplesiomorphy

Question 18

. List 2 terms used to describe the teeth in living mammals (with some exceptions in each case)

Answer 18

Heterodont and diphyodont

Question 19

Answer 19

Question 20

What is the correct name of the bone?

Answer 20

Ulna

Question 21

Which of the following is part of the pelvic girdle in monotremes and marsupials but not eutherians?

Answer 21

Epipubic bones

Question 22

Question 23

The ____ Era, also known as the Age of _____, followed the _____ Era, also known as the Age of _____ the two are separated by the _____ Boundary around __ million years ago.

Answer 23

Cenozoic, Mammals, Mesozoic, Dinosaurs, K/T, 65

Question 24

True or False: Mesozoic mammals were largely unspecialized and did not evolve notable locomotory or ecological specializations compared to modern mammals.

Answer 24

False

Question 25

In mammals, the ____ articulates distally with the tibia and _____ when present and is relatively _____ proximally, which allows for a more ____ posture

Answer 25

Femur, fibula, offset, upright

Question 26

Which of the following is/are thought to have evolved independently two or more times in mammals?

Answer 26

Question 27

List three things adduced as evidence of endothermy in synapsids as discussed in lecture and briefly discuss the merits of each

Answer 27

Question 28

Contrast three craniodental characteristics between pelycosaurs and extant mammals

Answer 28

Question 29

Which of the following statements is true?

a. Monotremes are more closely related to metatherians than they are to eutherians b. Eutherians evolved from monotremes c. the ancestor of all mammals probably closely resembled living monotremes
d. none of the above

Answer 29

none of the above

Question 30

Label each of the structures indicated below in the ventral view of a platypus pectoral girdle.

Answer 30

Question 31

A mammal with 2 lower incisors has most likely lost phylogenetic

Answer 31

I₄

Question 32

What was the probable original function of hair and why do we think this?

Answer 32

Hair most likely evolved as a means of wicking sebaceous secretions to the skin to protect against the elements, not (as several of you wrote) insulations (reasons against this argument were given by both Kendall Mills and me in separate lectures; your textbook does not discuss the origin of hair). Full credit was also given for answers having to do with hair’s tactile function.