Marine Biology Exam Iii Ch 17

Front 1

Speciation

Back 1

-formation of new species
-requires some degree of isolation of populations
-results in reproductive incompatibility between them

Front 2

Local patterns of species diversity are often controlled by what?

Back 2

-short-term ecological interactions

Front 3

Regional patterns of species diversity are often controlled by what?

Back 3

Speciation and extinction

Front 4

Within-habitat
(Component of Diversity)

Back 4

= a contrast of diversity between two locales of similar habitat type (ex. muddy bottoms on the shelf versus the abyssal bottom)

Front 5

Between-habitat
(Component of Diversity)

Back 5

=contrast of diversity in two locales of differing habitat type (ex. sand vs. mud bottoms)

Front 6

Latitudinal diversity gradient

Back 6

one of the most pervasive gradients; number of species increases toward the equator

Front 7

Between-ocean differences

Back 7

Pacific biodiversity appears to be greater than Atlantic

Front 8

Within-ocean differences

Back 8

from a central high of biodiversity in the SW Pacific, diversity declines with increasing latitude and less so with increasing longitude, away from the center

Front 9

Inshore-estuarine habitats

Back 9

estuaries tend to be lower in diversity than open marine habitats

Front 10

Short-term ecological interactions
(Explanations of Diversity Differences)

Back 10

-- presence of predators might enhance coexistence of more competing species, competitor might drive inferior species to a local extinction

Front 11

Complex recent historical events
(Explanations of Diversity Differences)

Back 11

-may explain some current regional differences in species diversity (e.g., diversity gradient in tropical American coral reefs may be partially due to extinctions around periphery of province)

Front 12

center of origin theory
(Explanations of Diversity Differences)

Back 12

-Greater speciation rate
-argues that tropics are source of most new species, some of which may migrate to higher latitudes

Front 13

Area
(Explanations of Diversity Differences)

Back 13

-greater area might result in origin of more species (b/c of larger diversity of habitats within a larger area), but also lower extinction rate of species living over greater geographic ranges (b/c of higher population sizes, and presence of more refuge habitats)

Front 14

Habitat stability
(Explanations of Diversity Differences)

Back 14

a stable habitat may reduce the rate of extinction, because species could persist at smaller population sizes (possible explanation of deep-sea maximum of species richness)

Front 15

Sea-level fluctuations
(Explanations of Diversity Differences)

Back 15

sea level fluctuations, such as during the Pleistocene, might have created barriers during low stands of sea level, leading to isolation and speciation. This mechanism has been suggested as increasing the number of species in the SW Pacific in coral reef areas

Front 16

Center of Origin Hypothesis

Back 16

-high diversity centers are places where more species are produced and retained and also a source of colonization to peripheral regions where diversity is lower

-is supported b/c of fossil evidence

-first occurences may be at tropics than at high latitude

Front 17

Conservation Strategies:
Individual species

Back 17

-preserve abundance of target species, such as large carnivores, marine mammals

Front 18

Conservation strategies:
Conserve total biodiversity of a region

Back 18

-focus on hotspots of high diversity

Front 19

Conservation Strategies: Conserve ecosystem function

Back 19

-concern is focused on species that are important in ecosystem processes (such as primary production, nutrient cycling, decomposition)

Front 20

Conservation strategies:
Establish economic value of ecosystem by evaluating its ecosystem services

Back 20

-ecosystems have human value that can be quantified in money (resources, water supply, recreation, etc.)

Front 21

Conservation Strategies:
Marine Protected Areas (Marine Reserves)

Back 21

-Set aside a fraction of ecosystem area/volume to allow populations to thrive and spill over into remaining unprotected sites

-Population density, body size, biomass, biodiversity all found to be higher within marine reserves

Front 22

Properties of Successful Invaders

Back 22

-Vector
-Invasion frequency
-Ecological suitability of target habitat
-Survival of initial population variation

-slide 33, lecture 31