Question 1

One explanation for the evolution of insect wings suggests that wings began as lateral extensions of the body that were used as heat dissipaters for thermoregulation.When they had become sufficiently large,these extensions became useful for gliding through the air,and selection later refined them as flight-producing wings.If this hypothesis is correct,modern insect wings could best be described as

Accepted Answer

A) adaptations. 
B) mutations. 
C) exaptations. 
D) isolating mechanisms.

Question 2

Many species of snakes lay eggs.However,in the forests of northern Minnesota where growing seasons are short,only live-bearing snake species are present.This trend toward species that perform live birth in a particular environment is an example of

Accepted Answer

A) natural selection. 
B) sexual selection. 
C) species selection. 
D) goal direction in evolution.

Question 3

The loss of ventral spines by modern freshwater sticklebacks is due to natural selection operating on the phenotypic effects of Pitx1 gene

Accepted Answer

A) duplication (gain in number). 
B) elimination (loss). 
C) mutation (change). 
D) silencing (loss of expression).

Question 4

The history of continental drift on Earth has

Accepted Answer

A) allowed for speciation to occur. 
B) allowed for both speciation and extinction to occur. 
C) caused speciation rates to exceed extinction rates. 
D) caused speciation to equal extinction rates.

Question 5

Records of extinctions on the planet indicate that

Accepted Answer

A) although Earth has experienced five mass extinctions,the diversity of life appears to be greater now than ever before. 
B) mass extinctions on the planet have caused a steady decline over hundreds of millions of years,both in the numbers and abundance of species. 
C) mass extinctions have caused the number of predator genera to decline over time. 
D) extinction rates are highest when global temperatures are lower.

Question 6

What is true of the fossil record of mammalian origins?

Accepted Answer

A) It is a good example of punctuated equilibrium. 
B) It shows that mammals and birds evolved from the same kind of dinosaur. 
C) It includes transitional forms with progressively specialized teeth. 
D) It indicates that mammals and dinosaurs did not overlap in geologic time.

Question 7

A difficulty in presenting evidence for a sixth mass extinction is

Accepted Answer

A) that tropical rain forests harbor many unknown species. 
B) that species numbers are declining because of habitat loss. 
C) introduction of new species. 
D) increased global temperatures.

Question 8

What is critical to understand about the following statement? Eyes could not have evolved over time,part by part,because for the eyeball to function at all,it needs all of its parts working together.

Accepted Answer

A) Many different taxa rely on simple eyes to survive,which function and are missing some components of more complex eyes. 
B) An eye can only work to form and image and transmit it to the brain if it has all components. 
C) The purpose of an eye is always to form and image and transmit the image to the brain. 
D) Eyes that distinguish only light from dark are too simple to be useful.

Question 9

The existence of evolutionary trends,such as increasing body sizes among various horse species,is evidence that

Accepted Answer

A) a larger volume-to-surface area ratio is beneficial to all mammals. 
B) an unseen guiding force is at work. 
C) evolution always tends toward increased complexity or increased size. 
D) in particular environments,similar adaptations can be beneficial in more than one species.

Question 10

Which of these fly organs,as they exist in current fly populations,best fits the description of an exaptation?

Accepted Answer

A) wings 
B) balancing organs 
C) mouthparts 
D) thoraxes 
E) walking appendages

Question 11

Hox genes are a group of related genes that

Accepted Answer

A) control the body plan of an embryo and are conserved across many taxonomic groups. 
B) do not affect change in location. 
C) do not affect plant development. 
D) control the body plan of an embryo of a small portion of animal species.

Question 12

Which statement about the atmosphere and life on Earth is correct?

Accepted Answer

A) Life on Earth arose once oxygen was present. 
B) Life on Earth arose once temperatures of gases warmed. 
C) Life on Earth arose before oxygen was present. 
D) Life on Earth arose once the products of photosynthesis such as oxygen were present.

Question 13

Which effect of continental drift would allow scientists to track the history of life on the planet?

Accepted Answer

A) alteration of habitat 
B) climate change 
C) allopatric speciation 
D) change in distribution of extinct animals

Question 14

The major evolutionary episode corresponding most closely in time with the formation of Pangaea was the

Accepted Answer

A) Cambrian explosion. 
B) Permian extinctions. 
C) Pleistocene ice ages. 
D) Cretaceous extinctions.

Question 15

In the 5 to 7 million years that the hominid lineage has been diverging from its common ancestor with the great apes,dozens of hominid species have arisen,often with several species coexisting in time and space.As recently as 30,000 years ago,Homo sapiens coexisted with Homo neanderthalensis.Both species had large brains and advanced intellects.The fact that these neurological traits were common to both species is most easily explained by which of the following?

Accepted Answer

A) species selection 
B) uniformitarianism 
C) sexual selection 
D) convergent evolution

Question 16

Which group of tetrapods had the first examples of specialized teeth?

Accepted Answer

A) synapsids 
B) therapsids 
C) early cynodonts 
D) late cynodonts

Question 17

Figure 23.3
-According to the theory of seafloor spreading,oceanic islands,such as the Hawaiian Islands depicted in Figure 23.3,form as oceanic crustal plates move over a stationary "hot spot" in the mantle.Currently,the big island of Hawaii is thought to be over a hot spot,which is why it is the only one of the seven islands that has active volcanoes.What should be true of the island of Hawaii?
1)Scientists in search of ongoing speciation events are more likely to find them there than on the other six islands.
2)Its species should be more closely related to those of nearer islands than to those of farther islands.
3)It should have a rich fossil record of terrestrial organisms.
4)There is a good chance of finding endemic species on this island.
5)On average,it should have fewer species per unit surface area than the other six islands.

Accepted Answer

A) 1,2,and 3 
B) 1,2,and 5 
C) 1,2,3,and 4 
D) 1,2,4,and 5

Question 18

Which event stimulated the rapid development of eukaryotes?

Accepted Answer

A) extinction of some organisms 
B) addition of oxygen to the atmosphere 
C) origin of multicellular organisms 
D) colonization of land

Question 19

If we visualize the time that has passed since the origin of our solar system and Earth,or about 4.6 billion years,as a one-hour clock,then out of one hour,multicellular eukaryotes have been present on the planet for about

Accepted Answer

A) 45 minutes. 
B) 15 minutes. 
C) 10 minutes. 
D) 30 seconds. 
E) 1 second.

Question 20

The following questions refer to this hypothetical situation.
A female fly,full of fertilized eggs,is swept by high winds to an island far out to sea.She is the first fly to arrive on this island and the only fly to arrive in this way.Thousands of years later,her numerous offspring occupy the island,but none of them resembles her.There are,instead,several species,each of which eats only a certain type of food.None of the species can fly,for their flight wings are absent,and their balancing organs (in other words,halteres)are now used in courtship displays.The male members of each species bear modified halteres that are unique in appearance to their species.Females bear vestigial halteres.The ranges of all of the daughter species overlap.
-If these fly species lost the ability to fly independently of each other as a result of separate mutation events in each lineage,then the flightless condition in these species could be an example of

Accepted Answer

A) adaptive radiation. 
B) species selection. 
C) sexual selection. 
D) allometric growth.

Exam 23: Broad Patterns of Evolution