Final Exam - exam 2

Question 1

This is the biggest short term (next 50 years) threat to most species on the planet:

Answer 1

habitat loss

Question 2

Apex predators can often serve this important ecological role in an ecosystem where they disproportionately (by total biomass) impact ecosystem function:

Answer 2

keystone species

low biomass, high impact

Question 3

This 1973 treaty regulates the international trade of animals and plants

Question 4

When portions of a large forest are logged and fragmented into smaller sections, the number of species over time in remaining intact forest patches tend to decline, then eventually reach a dynamic equilibrium. This process is called:

Answer 4

relaxation

Question 5

In tropical forests, occasionally bird species that remain in intact forest patches refuse to fly to other forest patches, which is a great example of what kind of habitat loss-related effect?

Answer 5

matrix effect

Question 6

In the paper by Maigret et al. (2019), surface mining in Appalachian forests appears to particularly destroy ridgetop habitat for this local predator:

Answer 6

timber rattlesnake

Question 7

Deforestation in the Amazon rainforest is closely tied to this agricultural practice:

Answer 7

cattle ranching

Question 8

This type of speciation is driven by the formation of geographic barriers that physically separate populations, leading to unique selective pressures for each, ultimately creating distinct species over time.

Answer 8

allopatric

Question 9

This type of speciation occurs when local selection pressures within contiguous populations lead to genetic differences (polymorphisms) and eventually reproductive isolation between different groups.

Answer 9

sympatric

Question 10

Madagascar is often labels the “8th continent” because it has unique species found nowhere else, a term known as:

Answer 10

endemic

Question 11

The rapid speciation of a single colonizing species into multiple daughter species (ie, Hawaii, Galapagos Islands) is known as:

Answer 11

adaptive radiation

Question 12

In the paper Davis et al. (2021) the future of black bear and panther habitat in Florida is projected to be reduces in most scenarios by ___________ and _________.

Answer 12

sea level rise

urbanization

Question 13

Myer et al. (2007) found that the loss (up to 99% decline) of many species of predatory sharks impacted the Chesapeake Bay area when trophic cascades ultimately led to the large decline of what group?

Answer 13

scallops

Question 14

Fossil evidence suggests that the number of species over geologic time (~3.5 billion years) has:

Answer 14

increased

Question 15

Biomes are categorized based on ___________ and _____________.

Answer 15

temperature and precipitation

Question 16

A hypothesis and associated diagram that describes the history of evolutionary descent of a group of organisms from a common ancestor is known as a ___________.

Answer 16

cladogram

Question 17

________ _____________ is the sum of all species per unit area and the simplest measure of biodiversity

Answer 17

alpha diversity

Question 18

This type of species is defined by groups with interbreeding individuals that are reproductively isolated from other groups:

Answer 18

biological species

Question 19

The Great American Biotic Exchange and Beringia are both great examples of:

Answer 19

land bridges

Question 20

These “tropical rain forests” of the oceans have extremely high productivity compared to the open ocean and support 8% of all fish species. However, they are threatened by a multitude of factors.

Answer 20

coral reefs

Question 21

What region of the earth will have the smallest number of species for a given taxa?

Answer 21

the poles
Species richness increases towards the equator and decreases towards the poles. The equator has more biodiversity because the environment is more stable (no/less seasons), has high primary productivity, and the humidity and high temperatures to allow for the creation of many niches.

Question 22

Explain the temperate forest: intermediate disturbance hypothesis

Answer 22

This hypothesis suggests that biodiversity will be maximized in a temperate forest ecosystem that has an intermediate level of disturbance. The reasoning is that low disturbance allows dominant species to overtake and high disturbance does not allow species to recuperate, so an intermediate level of disturbance would be ideal to have the most diversity.

Question 23

There are two hypotheses related to the relationship between ecosystem function and species richness. Identify and explain each hypothesis.

Answer 23

The redundant hypothesis - states that if one species is removed then another will fill all or most of its ecological role.

The Rivet hypothesis - states that all species are equally important in their ecological role.

Question 24

What two factors are key in determining species richness on an island?

Answer 24

size of the island

distance from the mainland

Question 25

In natural populations or in highly fragmented ones, these kinds of populations are loosely connected by the occasional exchange of individuals:

Answer 25

metapopulations

Question 26

In a metapopulation, units that produce a net surplus are called __________ ____.
Units that produce a net loss are called ___________ _______.

Answer 26

population source

population sink

Question 27

Why are high rates of speciation favored by mass extinctions?

Answer 27

Mass extinctions can take out dominant species and give rise to new niches allowing for an increase in speciation.

Question 28

Why are high rates of speciation favored by the arise of new biological groups (taxa)?

Answer 28

The arise of new taxa yields more species over time, thus increasing speciation.
This can also be associated with adaptive radiation which gives rise to rapid speciation through the production of many different daughter species.

Question 29

Why are high rates of speciation favored by major land separations?

Answer 29

Major land separations are an aspect of allopathic speciation where an individual species can be separated by a land or water barrier and over the course of generations the single species has developed into two different species, thus allowing an increase in speciation.

Question 30

Beta diversity is:

Answer 30

An index of change of species from one community to the next

Question 31

In terms of ecosystems, thus area is considered to be the most endangered in the US.

Answer 31

Tall grass prairies

Question 32

Intensive use of agricultural fertilizers can lead to excess runoff of pollution into waterways which can transform the system from low to high nutrient levels, a process called _______, and which has lead to _______________ at the mouths of rivers where few species can survive due to low oxygen.

Answer 32

Eutrophication

Hypoxic “dead zones”

Question 33

How sharp or different the edge or boundary is between two different habitat types is known as:

Answer 33

Contrast

Question 34

This migratory fish brings nitrogen from the ocean and deposits it via its death on river banks and surrounding land, thereby helping to fertilize these areas.

Answer 34

Salmon

Question 35

Which of the following effects can endocrine disrupting compounds have on physiology?

Answer 35

Carcinogenic, teratogenic, metabolic, and reproductive

Question 36

The scaly, gentle creatures that roll up when handled and which have become the most heavily trafficked mammals in the world are known as:

Answer 36

Pangolins

Question 37

Pangolin scales are being used for what purpose?

Answer 37

medicine

Question 38

Other than size and rarity, list 5 characteristics of species that may make them vulnerable to extinction and more likely to end up on the IUCN red list

Answer 38

• low fecundity
• wide ranging species
• species naive to humans
• non vagile species (poor dispersers)
• species that live in stable environments