Island Biogeography & Ecomorphs

Front 1

island

Back 1

isolated patches of niche space

Front 2

types of islands?

Back 2

-oceanic islands (the first ones we think of)
-ponds <3
-mountains
-basins (a portion of land that is drained by a river/ i.e. whose water drains into a river)
-remnant forests (patches of older forest surrounded by younger forest)

Front 3

species richness

Back 3

the number of different species in a given ecosystem (disregards population size e.g. there could be thousands of turtles on an island and 5 tigers and richness is as high as if there were thousands of tigers as well)

Front 4

when immigration is HIGHER, extinction is

Back 4

LOWER

Front 5

when immigration is LOWER, extinction is

Back 5

HIGHER

Front 6

when islands are LARGER, species richness is

Back 6

HIGHER

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when islands are SMALLER, species richness is

Back 7

LOWER

Front 8

if an island is FURTHER from the mainland, species richness is

Back 8

LOWER

Front 9

if an island is CLOSER to the mainland, species richness is

Back 9

HIGHER

Front 10

when islands are CLOSER to the mainland, immigration is

Back 10

HIGHER

Front 11

when islands are FURTHER from the mainland, immigration is

Back 11

LOWER

Front 12

equilibrium

Back 12

stable rate of change in the environment

Front 13

allometry

Back 13

relationship of body size and shape to behavior

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target effect

Back 14

immigration rate is higher by chance on larger islands simply due to their large size
(it is more likely that one will hit a large dartboard than a small one)

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rescue effect

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extinction rate is lower on less isolated islands because of the higher possibility of individuals from another population on the mainland and/or neighboring islands to replenish a given population

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species-area relationship

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as the size of an island increases, so does species richness

Front 17

do landbridge islands follow the species-area rule?

Back 17

yes, but the question is whether or not this is due more to 1) immigration/ emigration/ extinction or 2) species diversification after colonization

Front 18

oceanic islands

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generally are species depauperate aka low in species richness and are colonized mainly by C-T and T-G anoles

Front 19

are the Lesser Antilles more similar to the landbridge islands of the Greater Antilles or the oceanic islands?

Back 19

oceanic

Front 20

define taxon cycle

Back 20

the sequential phases of expansion and contraction of the geographic ranges of species

Front 21

taxon cycle are more at play/ more apparent in the _______ Antilles

Back 21

Lesser

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character displacement

Back 22

if similar species' geographic distribution does not overlap, then they will have similar characteristics, but if their distributions do overlap, then their characteristics can change (e.g. size) so that they occupy slightly diff. niches

Front 23

example of a change in taxon cycle: phases of colonization can be followed by range ________ (a. expansion b. contraction)

Back 23

b. contraction

Front 24

3 possibilities for changes in body size seen in the Lesser Antilles

Back 24

1) character displacement
2) taxon cycles
3) sympatric speciation

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taxon cycles are altered by _______ & _______

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immigration & emigration

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sympatric speciation

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when new species evolve from a single ancestral species whiling inhabiting the same geographic region

Front 27

character displacement

Back 27

when differences between two similar species (whose geographic regions overlap) are accentuated

Front 28

sympatric speciation

Back 28

when new species evolve from a single ancestral species whiling inhabiting the same geographic region

Front 29

character displacement

Back 29

when differences between two similar species (whose geographic regions overlap) are accentuated

Front 30

vicariance

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the separation or division of a group of organisms by a geographic barrier (causes allopatric speciation)

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cladogenesis

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the formation of a new group of organisms or higher taxon by evolutionary divergence from an ancestral form
(caused by speciation)

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stabilizing selection

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intermediate phenotype favored

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directional selection

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when a single, more extreme phenotype is favored, resulting in a continuous shift in allele frequency toward that phenotype (can occur when two species have overlapping niches)

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divergent selection

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when allele frequencies move toward the extreme phenotypes, decreasing competition and allowing coexistence

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divergent selection results in...

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coexistence of two species

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directional selection results in...

Back 36

extinction of one species

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stabilizing selection means selection against...

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extreme phenotypes