Exam 5 Island Biogeography

Question 0

A well established community with filled niches may not allow for new species.

Answer 0

Resistance to Invasion

Question 1

Increasing distance =

Answer 1

Less likely to cross, fewer species can do it.

Question 2

History of potential interchange =

Answer 2

More likely to resist invaders

Question 3

The exchange between North and South America as they came together.

Answer 3

The Great American Biotic Exchange

Question 4

Construction of the Suez Canal connecting the Mediterranean Sea and the Red Sea. Opened in 1969. 102 miles long at sea level, no locks. Passed through hyper saline lakes.

Answer 4

The Lessepsian Exchange

Question 5

Where a taxon first evolved

Answer 5

Center of Origin

Question 6

Thought that most derived forms of a taxon would be at the origin.

Answer 6

Mathews (1900’s)

Question 7

Center of origin for sea snakes in Australia/New Guinea based on:

Answer 7

1. Most diversity
2. Most primitive species
3. Ancestors there

Question 8

Study of the distribution of lineages

Answer 8

Phylogeography

Question 9

Any isolated geographic area.

Answer 9

Island

Question 10

Small land masses isolated by an expanse of water.

Answer 10

Typical Islands

Question 11

Island that was once joined to an adjacent continent. Same biota at some point in history.

Answer 11

Continental Islands

Question 12

Separated from mainland in initial split:

Greater Antilles/Cuba

Answer 12

80 mya

Question 13

Separated from mainland in initial split:

New Zealand

Answer 13

80-90 mya

Question 14

Separated from mainland in initial split:

Madagascar

Answer 14

100 mya

Question 15

Separated from mainland in initial split:

Seychelles

Answer 15

65 mya

Question 16

An island that arose from the ocean floor and has never been connected to a continent. Thus all biota came via long distance dispersal. Species suited for long distance dispersal.

Answer 16

Oceanic Islands

Question 17

Islands/volcanoes that formed at/near mid ocean trenches.

Answer 17

Aleutians
Lesser Antilles
Lesser Sundra Islands

Question 18

Islands formed at a Hotspot or fracture zone.

Answer 18

Hawaii Islands (Hot spot)
Galápagos Islands (Fracture zone)

Question 19

Other types of Islands

Answer 19

• isolated mountaintops
• isolated nature preserves
• lakes etc.

Question 20

Wallace influenced by observational studies in…

Answer 20

Malay Archipelago

Question 21

The number of species inhabiting an island represents equilibrium between opposing rates of colonization and extinction.

Answer 21

Basic Theory

Question 22

The Equilibrium Theory

Answer 22

The number of species inhabiting an island represents a dynamic equilibrium between opposing rates of immigration and extinction.

Question 23

Very near islands received repeated propagules of existing species and thus those species are not extirpated.

Answer 23

Rescue Effect

Question 24

Used Methyl Bromide to kill all Arthropods and terrestrial animals; vegetation unharmed. Small mangrove islands in Florida, Keyes

Answer 24

Simberloff and Wilson (1969, 1970)

Resulted in rapid recolonization within one year. Supported equilibrium theory

Question 25

Censuses Arthropod individuals and number of species on thistle plants in Southeastern Arizona.

Answer 25

Brown and Kodric Brown (1977)

Results: mostly supported equilibrium theory and it’s predictions.
Larger plants = increased # of individuals and species.
Longer distance from source = decreased #’s
Near plants = increased numbers
Small plants had higher turnover of individuals and species.
Near plants had lower turnover rates. (Different than expected)

Question 26

Island size does affect immigration =

Answer 26

Target Area Effect

Question 27

Below a certain island size, species richness is constant =

Answer 27

Small Island Effect

Question 28

Organisms with longer generation times have:

Answer 28

Lower turnover rates

Question 29

Problems with the equilibrium theory:

Answer 29

1. Many islands biota are not in equilibrium
2. Ignores characteristics of a particular species and interspecific interactions.
3. Colonization and extinction are seen as independent processes.
4. Larger islands are larger targets
5. Immigrants may come from more than one location.
6. Species richness is affected by speciation in location
7. Larger areas usually have larger and more diverse habitats

Question 30

“Still increasing to reach equilibrium”

Answer 30

North American Great Lakes: 10,000 years old, few fish species, some speciation.

Africa Great Lakes: 5 mya, many fish species, much speciation and adaptive radiation.

Question 31

Plant dispersal to islands.

Answer 31

• bird carried is most common
• wind dispersed 2nd
  Galápagos Islands plants = 378 colonizations, 60% by birds, 31% by wind, 9% by seeds.