Bio Exam 2 defenitions

Define biogeography

Study of the distribution of species through time and space

Alfred Russel Wallace

Co-discoverer of evolution via evolution but main contribution was the study of species distributions across large spatial scales

Wallace Line

Boundary separating the Asian and Australian ecozones (Species on Asian islands more similar to Australia than Asian because of fault lines)

Biogeographic Zones

large areas that have particular flora and fauna often due to isolation during continental drift (areas of unique phylogenetic traits due to Earth's plates)

3 Basic biogeographic patterns on Earth

1. Species richness and composition vary between continents
2. Species richness and composition vary between latitude
3. Same community type or biome can vary in species richness and composition

How do humans influence species richness and composition between continents?

Dispersal among continents has increased because humans have indirectly facilitated dispersal

How did species richness and composition varying between continents arise?

Continental drift and is maintained by limited dispersal

Where is the greatest amount of diversity?

lower latitudes; equator

What are the three theories as to how the latitudinal diversity gradient arose?

-more energy in the tropics
-more land area in the tropics
-more environmental stability in the tropics

What types of animals are the exception to greater diversity at the equator?

seabirds, marine productivity is higher in temperate and polar oceans

ecological biogeography

accounts for present distribution in terms of interactions between organisms and their physical and biotic environments

Historical Biogeography

Reconstruction of the origin, dispersal, and extinction of taxa and biotas

Compare and contrast Biogeographic zones vs Biomes

Biogeographic zones characterized by shared evolutionary histories
BIOMES are characterized by their ecological and abiotic characteristics, esp. climate!

Biogeography Regional Scale

-Areas with uniform climate
-Species restricted to that region by dispersal limitations

Landscape

Physical geography of a region (shapes extinction, immigration, emigration)

Gamma Diversity

Species diversity at the regional scale; the regional species pool

How does the human footprint relate to biomes?

Human activity influence the distribution of biomes (humans impact the environment)

Biosphere

A bunch of biomes; Zone of life on Earth

Why may there be similar biotic assemblages in distinct continents in same biomes?

Convergent evolution

How are aquatic biomes characterized?

type of water

How ware terrestrial biomes characterized?

Most common growth form of plants

What creates the regional species pool?

Continental drift

Biome

Large scale biogeographical community with similar life forms and environmental conditions

What are the filters that influence the levels of diversity

Species supply filter- ability of species to disperse to different areas
Abiotic filter- physical and chemical characteristics of an environment that may prevent a species from inhabiting a particular area
Biotic filter- nteractions between species that may prevent a species from inhabiting a particular area

Alpha Diversity

Local species diversity (diversity patterns driven by physical conditions and species interactions)

Beta Diversity

change in species number and composition (turnover) from one community to another; connects regional and local scales

What does a high beta diversity mean?

Large amount of change in species number and composition

What is species composition in the local community limited by?

Those in the regional pool

What increases local diversity

-increased regional diversity
-increased rate of dispersal
-physical condition tolerated by more species
-tradeoffs that cause species effects on themselves to be greater than on other species

What is the species-area relationship?

Species richness increases with area sampled; increase area, more species; rate of increase varies, but will eventually level off

Ecological complexity
o How does this relate to biodiversity?

What is an island?

isolated areas surrounded by dissimilar habitat

How is the theory of island geography helpful?

It can be applied to study habitat fragmentation, habitat loss, human land use

Theory of Island Biogeography

-Number of species on an island depends on a balance between immigration or dispersal rates and extinction rates
-equilibrium number is the number of species that should theoretically "fit" on the island

What controls island extinction?

island size (smaller island, higher chance of extinction)

What controls island immigration?

distance from source population (further from source, lower immigration rates)

What does an ecological niche include

-organism's adaptations
-use of resources
-interactions with other organisms
-lifestyle to which it is fitted in its community

Fundamental niche

the full set of resources plus other biotic and abiotic requirements of a species

Realized niche

restricted set of resources a species is limited to, due to species interactions

How does biodiversity relate to resilience?

Resilience is the capacity of a system to respond to a perturbation or disturbance by resisting damage and recovering quickly (increase resilience by increasing biodiversity)

What are the 3 aspects of biodiversity

-Species richness
-Genetic diversity
-Ecosystem diversity

Biodiversity

the degree of variation of life forms within a given ecosystem, biome, or even an entire planet

Why is biodiversity important?

Provide fundamental life-support services and produces human well-being

What are the 4 ecosystem services?

-Supporting (creating oxygen)
-Regulating (cleaning water)
-Provisioning (food)
-Cultural (bald eagle)

Population

all the members of a single species in a given area

Biotic community

An assemblage of interacting populations in the same environment

What is the term for multiple ecosystems interacting?

Landscape

Ecosystems

an interacting system of the biotic community and its physical environment (abiotic factors)

Ecological maxim \#6: Life is impossible without interactions!
o Slide 12: explain "biotic resistance"

Density-dependent factors

Birth, death, and dispersal rates change as the density of the population changes

What type of growth is population?

Logistic

What influences population growth rate?

population density (N), per capita intrinsic growth rate (r) , and carrying capacity (K)

What is population growth rate controlled by?

Birth and death rate

Define competition

an interaction between individuals in which each is harmed by their use of limiting resources

Interspecific competition

competition between individuals of different species

Intraspecific competition

competition between members of the same species

Predation, herbivory, parasitism

Win, lose

Mutualism

Win, win

Amensalism

Lose, no impact

Commensalism

Win, no impact evolutionarilly

Direct Competition

species perform antagonistic actions that directly interfere with the ability of their competitors to use a limiting resource

Indirect Competition

Competing for the same resources

Competitive Exclusion Principle

two species that use a limiting resource in the same way (same ecological niche) cannot coexist indefinitely

What conditions allow competitors to coexist?

Environmental variation (individuals dominant in one environment might not be dominant in another)

Intermediate Disturbance Hypothesis

Species diversity will be greatest at intermediate levels of disturbance. At low levels of disturbance, competition regulates diversity. At high disturbance levels, many species cannot survive.

Resource Partitioning

Species use limited resource in different ways (and at different times); increases diversity

Predation cycle

Predators consume prey, reducing prey population. As prey decreases, predator population decreases due to lack of food. With few predators, the prey population increases and the cycle repeats.

Do carnivores have broad or narrow diets?

Broad

Do herbivores have broad or narrow diets?

Narrow

Optimal foraging theory

Views foraging behavior as a compromise between benefits of nutrition and costs of obtaining food.

What does optimal foraging theory depend on?

Encounter rate and handling (digestion) time

What makes a predator an optimal forager?

Maximize energy gained and minimize energy used to capture prey

What prey defense adapatations?

-Physical defenses (large)
-Behavior (foraging in cover)
-Escaping predators (mimicry)

Why are many herbivores specialists?

Plants are well defended

What are plant defenses to reduce herbivory?

-structural (spines)
-chemical (toxins)
-secondary chemcials

How can evolution impact predation cycles?

Allele frequency in prey can change, causing unusual cycles (maximums correspond with minimums)

Trophic cascade

indirect effects in a community that are initiated by a predator

What are the implications of facilitative relationships?

Ecological, diversification, and evolutionary

Facilitation

Positive interspecies interactions

Obligate mutualisms

neither species can survive without the other

Facultative mutualisms

species benefit from one another but exert no selective pressure on one another

Service mutalisms

One partner performs an ecological service for the other

Can mutualistic relationships change to another type of interaction?

Yes

Keystone Species

Effect on energy flow and community structure disproportionate to its abundance or biomass

Species diversity

Measure that combines species richness and eveness

Species richness

number of species in a community

Species evenness

relative abundances compared with one another

What is species richness positively related to?

community stability

Foundation species

A species that has large, community-wide effects by virtue of its size or abundance, its strong competitive ability, or its provision of habitat or food for other species (usually giant plants)

Ecosystem Engineers

Directly influence the community by creating, modifying, or maintaining physical habitat for itself and other species

Where might you find simple epithelium tissue?

Lining of cavities

Where might you find stratified epithelium tissue

skin

Toxins released by Vibrio cholerae target the tight junction in the epithelia lining the GI tract. What kinds of signs and symptoms would you expect to result and why?

Fluids leaking between the cells causing diarrhea, dehydration, electrolyte imbalance

1. What are the structural characteristics that define connective tissue? How do each of these characteristics contribute to CT function (and what are these functions)? What types of tissues are classified as CT? What distinguishes between the different types of CT?

What features do all muscle types have in common?

Specialize for contraction and contain actin and myosin

Where is striated muscle found and why does it appear this way?

Skeletal and cardiac muscle because the arrangement of actin and myosin filaments create a repeating pattern of light and dark bands

What unique structural feature does cardiac muscle have that no other muscle tissue type has?

Intercalated disks and contain gap junctions (electrical signaling) and desmosomes (structural support)

What is the function of the intercalated disks

ensuring rapid and coordinated contraction of the heart, maintaining structural integrity of the heart muscle, and providing resistance to mechanical stress during the contraction and relaxation of the heart

How does surface area affect rate of diffusion? Why is this important for biological tissues?

The larger the surface area, the faster the diffusion rate. This is important in biological tissue because diffusion is vital in the transport of nutrients and oxygen

Celiac disease is an autoimmune disorder of the small intestine that causes the intestinal villi to atrophy. Patients with celiac disease may experience diarrhea, weight loss, anemia, and fatigue. Why would villous atrophy result in these kinds of signs and symptoms?

Less surface area, so less absorption