Species

Question 1

What is the goal of biogeography?

Answer 1

to understand the causes that underlie the patterns of distribution of organisms

Question 2

____ are the most commonly used taxonomic level of biogeographical analysis

Answer 2

species

Question 3

List the 5 levels of organization:

Each of these systems is a subset of the higher one, forming a ____

Answer 3

Individual
Population or species
community
landscape
biosphere

hierarchy

Question 4

individual=

Answer 4

any living being

Question 5

every individual has a boundary that separates the ___ processes of the organism from the ___ conditions of the environment. What happens through this boundary?

Answer 5

internal
external

Through this boundary, individuals exchange energy & material with their environment

Question 6

Individuals must acquire energy and nutrients from their enviro in order to survive. What’s the implication of this for their enviro?

Answer 6

In acquiring energy, individuals alter their environment and change what’s available for others (finite resources)

Question 7

Populations=

Answer 7

a group of organisms of the same species living in a particular area at the same time

Question 8

T/F

The boundary of a population is always natural

Answer 8

false

It can be natural or it can be determined by other factors (eg political)

Question 9

Populations exhibit 5 unique characteristics that individuals do not:
1
2
3
4
5

Answer 9

1. geographic range
2. abundance
3. density
4. change in size
5. composition (eg. young/ old/ breeding age)

Question 10

Communities=

Answer 10

all of the populations of species living in a particular area
(groups of same species + different species)

Question 11

Populations in a community interact with each other in a variety of ways. Give 3 examples

Answer 11

predator-prey
pollinators
decomposers

Question 12

t/f

the interactions within a community influence the number of individuals in each population

Answer 12

true

Question 13

ecosystem=

Answer 13

composed of one or more communities of living organisms interacting with their living and nonliving environments

Question 14

• The ____ of ecosystems can vary and are often not distinct

Answer 14

boundaries

Question 15

_____= complex ecological systems that can include thousands of different species living under a great variety of conditions

Answer 15

ecosystems

Question 16

landscapes=

Answer 16

includes multiple ecosystems that are connected by the movement of individuals, populations, matter, and energy

Question 17

T/F

Landscapes only include terrestrial ecosystems

Answer 17

false

aquatic and terrestrial

*can also include patchworks of different communities

Question 18

biosphere=

Answer 18

all the ecosystems and landscapes on earth

Question 19

_____ is the highest level of ecological organization

Answer 19

biosphere

Question 20

In the biosphere, distant ecosystems are linked together by exchanges of ___ and ___ carried by currents of wind/ water, & the movement of ____

Answer 20

energy
nutrients
organisms

Question 21

All transformations of the biosphere are internal, except:

Answer 21

energy that enters from the sun and the energy that is lost to space

Question 22

t/f

the biosphere holds all material that is has ever had and retains whatever waste materials humans generate

Answer 22

true

nothing leaves the biosphere except energy

Question 23

species=

Answer 23

groups of organisms that have many features in common

Question 24

species are generally reproductively isolated. Name an exception

Answer 24

hybrids

Question 25

What is the formal process of naming species?

Answer 25

Genus species binomial

Question 26

Give the 5 mechanisms of genetic differentiation

Answer 26

1. mutation= changes in DNA sequences (subtitution, deletion, insertion, inversion) 2. genetic drift 3. natural selection 4. gene flow 5. endosymbiosis: a symbiotic relationship where one organism lives inside the other (eg coral)

Question 27

T/F There is a geographical component to genetic divergence

Answer 27

true genetic drift and natural selection are facilitated by geographic isolation

Question 28

genetic drift and natural selection are facilitated by ____ _____

Answer 28

geographic isolation

Question 29

ultimately, geographic separation of populations facilitates ____

Answer 29

speciation

Question 30

vicariance and dispersal are both essential for species ____

Answer 30

formation

Question 31

vicariance=

Answer 31

pronounced enviro change can create a barrier to dispersal in the range of an ancestral species, isolating previously connected and inter-breeding pops

Question 32

give 2 examples of vicariance

Answer 32

rising sea levels, tectonic events eg loss of a land bridge

Question 33

dispersal=

Answer 33

movements of organisms from their natal (home) ranges eg to find a mate (usually the males)

Question 34

t/f distributional disjunctions were not due to barrier crossing but to barrier formation

Answer 34

true

Question 35

Evidence for transoceanic land bridges never surfaced, but we now know that vicariance is driven by ____ ____

Answer 35

plate tectonics

Question 36

T/F Dispersal: - helps prevent speciation - helps survival - can help prevent extinction - usually heavily influences species distribution

Answer 36

- false: dispersal leads to speciation - true - true - false: only influences species distributions if it results in immigration

Question 37

character displacement results in:

Answer 37

species being more different from one another where they coexist than when they live in separate, non-overlapping areas

Question 38

Give 2 examples of dispersal in birds

Answer 38

1. Hawaiian honeycreepers - ecological differentiation that enabled exploitation of diff niches (esp food) 2. Darwin's Finches - result of niche partitioning and character displacement when 2 closely related species inhabit the same enviro

Question 39

Give a potential limitation of dispersal

Answer 39

inhospitable habitat: organism cannot cross it (especially small ones) - could be a large expanse or can be small but still a barrier

Question 40

Give 2 ways that humans have affected species dispersal

Answer 40

- road building, forest clearing, etc have created barriers to dispersal for some species - humans have assisted in the dispersal of plants and animals for 1000s of years (intentionally or not)

Question 41

What can happen when individuals are introduced to a new area via dispersal?

Answer 41

- usually, they're never able to establish a viable population - sometimes though, they're able to grow into a population that expands their range over time= invasive species!

Question 42

The Ember Ash Borer is an example of a(n) ______ ______. What does it do?

Answer 42

invasive species Introduced to US in the 90s & has no natural predator: the larvae consume the tree under the bark & the tree dies :(

Question 43

_____ species provide opportunities to study dispersal. Why?

Answer 43

invasive they often have interesting and rapid dispersal mechanisms

Question 44

Explain how an invasive species might change the biodiversity in an area it arrives to

Answer 44

when they first arrive: - often biodiversity increases shortly followed by a biodiversity decrease invasive species replace endemic species (ie replacing specialized species with generalists)

Question 45

What are the 3 kinds of extinction? Give definitions

Answer 45

ecological/ functional extinction: so few individuals survive that the species' function is lost population extinction: population disappears, but there is probably another population somewhere species extinction: whole species disappears :(

Question 46

Explain the Red Queen Hypothesis

Answer 46

species must continuously evolve to keep pace with a constantly changing enviro (biotic and abiotic). Species often go extinct because they can't keep up

Question 47

Many of our geological transitions are based on species extinctions as viewed in the ____ _____

Answer 47

fossil record

Question 48

Pleistocene exinctions=

Answer 48

a recent large-scale extinction: large losses of megafauna ~15,000-8000 years ago

Question 49

Extirpation=

Answer 49

species disappears from one area but exists elsewhere