B-B2EVO09
chapter 18 – week 1: the geography of evolution
Futuyma & Kirkpatrick
This is a bullet point summary of the book Evolution by Futuyma & major patterns of distribution
Kirkpatrick. The chapters correspond to the ones taught in the
course Evolutie 2 at the University of Utrecht. ● geographic distribution of almost every species is limited, and
many higher taxa are likewise restricted (endemic);
summary key cosmopolitan = found worldwide (e.g. pigeon)
● Wallace’s line = break in taxonomic composition of animal
= definition ; extra information species among islands between S.E. Asia and Australia
: enumeration → causal relationship ● biogeographic realms = regions with characteristic animal and
# number of 2(+) two or more plant taxa; more the result of Earth’s history than of its current
climate or land mass distribution
⁕ Palearctic (Eurasia and northern Africa)
introduction ⁕ Nearctic (North America)
● biogeography may be divided into historical and ecological ⁕ Neotropical (Central and South America)
⁕ Ethiopian (sub-Saharan Africa)
⁕ Oriental (India and Southeast Asia)
biogeographic evidence for evolution ⁕ Australian (Australia, New Guinea, New Zealand,
nearby islands)
● pre-evolutionary worldview; Creator could’ve placed each ○ each biogeographic realm is inhabited by many higher taxa
species anywhere, or in many places at the same time that are much more diverse in that realm than elsewhere,
● Darwin showed that many biogeographical facts that make or are even restricted to that realm
little sense under the hypothesis of this special creation make ○ some taxa infiltrate neighboring realms → borders
sense if a species: between biogeographic realms aren’t sharp
1. has a definite site or region of origin ● some taxa have disjunct distributions = gaps in the
2. achieves a broader distribution by dispersal distributions; these taxa typically have different representatives
3. becomes modified and gives rise to descendant species in in each area they occupy
the various regions to which it disperses
● Darwin's 3 great facts of common ancestry: historical factors affecting geographic distributions
○ neither the similarity nor the dissimilarity of the ● often dispersal, vicariance, and extinction together explain
inhabitants of various regions can be wholly accounted for distributions
by climatal and other physical conditions (e.g. convergent ○ relict = population or taxon of organisms that was more
evolution) widespread or more diverse in the past
○ barriers of any kind, or obstacles of free migration are ● extinction
related in a close and important manner to the differences ○ species’ distribution may've been reduced by the
between the productions [organisms] of various regions extinction of some populations, and that of a higher taxon
(e.g. marine species on the eastern and western coasts of by the extinction of some constituent species
South America are different) ● dispersal = movement of individuals
○ inhabitants of the same continent or the same sea are ○ species expand their ranges by dispersal
related, although the species themselves differ from place ● vicariance = separation of populations of a widespread species
to place by barriers arising from changes in geology, climate, or habitat
● Darwin's evidence that species had not been created in ○ separated populations diverge, and often become
different places, but had a single region of origin: different subspecies, species, or higher taxa
1. remote oceanic island generally have organisms capable of
long-distance dispersal and lack organisms that don’t
2. many continental species of plants and animals have historical explanations of geographic distributions
flourished on oceanic islands to which humans have
transported them ● distribution of a taxon can’t be explained by an event that
3. most of the species on islands are clearly related to occurred before the taxon originated
species on the nearest mainland, implying that that was ● fossil record can show that a taxon proliferated in 1 area before
their source appearing in another
4. proportion of species restricted to an island is particularly ● geological data may describe barriers’ (dis)appearance
high when the opportunity for dispersal to the island is ● phylogenetic methods are the foundation of most modern
low studies of historical biogeography
1
, B-B2EVO09
chapter 18 – week 1: the geography of evolution
Futuyma & Kirkpatrick
vicariance ecological niches
● Isthmus of Panama closed 3 Mya and separated Caribbean and
● fundamental ecological niche of a population = set of all
western Pacific populations of marine species
environmental conditions in which a species can have positive
● breakup of Pangaea first into Laurasia and Gondwana, and
population growth
later into the modern land masses
● competitive exclusion principle = species that are too similar in
○ living species are descended from ancestors distributed
their use of limiting resources (e.g. food) can’t coexist
across Gondwana and became isolated on the several land
indefinitely
masses they now occupy; this scenario can apply only to
● related species often exhibit phylogenetic niche conservatism
clades that are older than the split between these land
= similar ecological requirements that they’ve inherited from
masses
their common ancestor
● it appears likely that dispersal explains more disjunct
distributions than vicariance
geographic patterns of diversity
dispersal
● dispersal may cause allopatric speciation (geographic isolation)
● latitudinal diversity gradient = number of species (and of
or parapatric speciation (reproductive isolation)
higher taxa such as genera and families) decline with increasing
● often a colonizing species gives rise to diverse descendant
latitude, both on land an in the ocean
species, sometimes forming an adaptive radiation
○ hypotheses to account for this pattern:
● Hawaiian Islands have formed as a tectonic plate has moved
1. ecological factors might enable more tropical species to
northwestward over a hot spot → sequential formation of
coexist in a stable community
volcanic peaks
⁕ factors might include high productivity because of
○ simplest phylogeny expected of Hawaiian species; basal
abundant solar energy, or fine partitioning of food
lineages occupy Kauai and youngest Hawaii
resources among many species
phylogeography (A) tropical locations might support higher equilibrium
● phylogeography = description and analysis of processes that number of species (carrying capacity)
govern geographic distribution of lineages of genes 2. diversification rate hypothesis = rate of increase in
○ processes include dispersal of organisms that carry the diversity has been greater in the tropics for a long time
genes (past movement of species), and the history by because of a higher speciation rate, a lower extinction
which dispersal and vicariance have determined their rate, or both
present distributions (B) diversification rate might be higher in the tropics
○ can be used to infer history of a populations’ spread 3. time and area hypothesis = most lineages have been
accumulating species for a longer time in tropical than in
extratropical environments
⁕ based on phylogenetic niche conservatism
geographic range limits: ecology and evolution
⁕ tropical areas might be a ‘cradle’ in which new species
arise at a high rate, or a ‘museum’ in which ancient
● species’ geographic distribution results not only from their
lineages persist
ancestors’ history, but also from current factors:
⁕ most lineages originated in tropical climates, and the
○ sexually reproducing species must find mates, must be
relatively few lineages that have evolved adaptations
able to survive physical conditions, find suitable resources
to the stressful temperatures and seasonal fluctuation
(food, habitat), and contend with other species
in food supply typical of the temperature zone are
(competitors, predators, and parasites)
younger that haven’t had time to become as divers →
(C) tropical regions have had more time to accumulate
dispersal limitations species
● border of a species’ geographic range is sometimes set by
unfavorable conditions (e.g. ocean’s edge)
○ this may be a nonequilibrial (temporary) border (e.g.
plants with trans-Atlantic distributions)
● plant species that reproduce by self-fertilization have broader
latitudinal ranges than outcrossing species
2
chapter 18 – week 1: the geography of evolution
Futuyma & Kirkpatrick
This is a bullet point summary of the book Evolution by Futuyma & major patterns of distribution
Kirkpatrick. The chapters correspond to the ones taught in the
course Evolutie 2 at the University of Utrecht. ● geographic distribution of almost every species is limited, and
many higher taxa are likewise restricted (endemic);
summary key cosmopolitan = found worldwide (e.g. pigeon)
● Wallace’s line = break in taxonomic composition of animal
= definition ; extra information species among islands between S.E. Asia and Australia
: enumeration → causal relationship ● biogeographic realms = regions with characteristic animal and
# number of 2(+) two or more plant taxa; more the result of Earth’s history than of its current
climate or land mass distribution
⁕ Palearctic (Eurasia and northern Africa)
introduction ⁕ Nearctic (North America)
● biogeography may be divided into historical and ecological ⁕ Neotropical (Central and South America)
⁕ Ethiopian (sub-Saharan Africa)
⁕ Oriental (India and Southeast Asia)
biogeographic evidence for evolution ⁕ Australian (Australia, New Guinea, New Zealand,
nearby islands)
● pre-evolutionary worldview; Creator could’ve placed each ○ each biogeographic realm is inhabited by many higher taxa
species anywhere, or in many places at the same time that are much more diverse in that realm than elsewhere,
● Darwin showed that many biogeographical facts that make or are even restricted to that realm
little sense under the hypothesis of this special creation make ○ some taxa infiltrate neighboring realms → borders
sense if a species: between biogeographic realms aren’t sharp
1. has a definite site or region of origin ● some taxa have disjunct distributions = gaps in the
2. achieves a broader distribution by dispersal distributions; these taxa typically have different representatives
3. becomes modified and gives rise to descendant species in in each area they occupy
the various regions to which it disperses
● Darwin's 3 great facts of common ancestry: historical factors affecting geographic distributions
○ neither the similarity nor the dissimilarity of the ● often dispersal, vicariance, and extinction together explain
inhabitants of various regions can be wholly accounted for distributions
by climatal and other physical conditions (e.g. convergent ○ relict = population or taxon of organisms that was more
evolution) widespread or more diverse in the past
○ barriers of any kind, or obstacles of free migration are ● extinction
related in a close and important manner to the differences ○ species’ distribution may've been reduced by the
between the productions [organisms] of various regions extinction of some populations, and that of a higher taxon
(e.g. marine species on the eastern and western coasts of by the extinction of some constituent species
South America are different) ● dispersal = movement of individuals
○ inhabitants of the same continent or the same sea are ○ species expand their ranges by dispersal
related, although the species themselves differ from place ● vicariance = separation of populations of a widespread species
to place by barriers arising from changes in geology, climate, or habitat
● Darwin's evidence that species had not been created in ○ separated populations diverge, and often become
different places, but had a single region of origin: different subspecies, species, or higher taxa
1. remote oceanic island generally have organisms capable of
long-distance dispersal and lack organisms that don’t
2. many continental species of plants and animals have historical explanations of geographic distributions
flourished on oceanic islands to which humans have
transported them ● distribution of a taxon can’t be explained by an event that
3. most of the species on islands are clearly related to occurred before the taxon originated
species on the nearest mainland, implying that that was ● fossil record can show that a taxon proliferated in 1 area before
their source appearing in another
4. proportion of species restricted to an island is particularly ● geological data may describe barriers’ (dis)appearance
high when the opportunity for dispersal to the island is ● phylogenetic methods are the foundation of most modern
low studies of historical biogeography
1
, B-B2EVO09
chapter 18 – week 1: the geography of evolution
Futuyma & Kirkpatrick
vicariance ecological niches
● Isthmus of Panama closed 3 Mya and separated Caribbean and
● fundamental ecological niche of a population = set of all
western Pacific populations of marine species
environmental conditions in which a species can have positive
● breakup of Pangaea first into Laurasia and Gondwana, and
population growth
later into the modern land masses
● competitive exclusion principle = species that are too similar in
○ living species are descended from ancestors distributed
their use of limiting resources (e.g. food) can’t coexist
across Gondwana and became isolated on the several land
indefinitely
masses they now occupy; this scenario can apply only to
● related species often exhibit phylogenetic niche conservatism
clades that are older than the split between these land
= similar ecological requirements that they’ve inherited from
masses
their common ancestor
● it appears likely that dispersal explains more disjunct
distributions than vicariance
geographic patterns of diversity
dispersal
● dispersal may cause allopatric speciation (geographic isolation)
● latitudinal diversity gradient = number of species (and of
or parapatric speciation (reproductive isolation)
higher taxa such as genera and families) decline with increasing
● often a colonizing species gives rise to diverse descendant
latitude, both on land an in the ocean
species, sometimes forming an adaptive radiation
○ hypotheses to account for this pattern:
● Hawaiian Islands have formed as a tectonic plate has moved
1. ecological factors might enable more tropical species to
northwestward over a hot spot → sequential formation of
coexist in a stable community
volcanic peaks
⁕ factors might include high productivity because of
○ simplest phylogeny expected of Hawaiian species; basal
abundant solar energy, or fine partitioning of food
lineages occupy Kauai and youngest Hawaii
resources among many species
phylogeography (A) tropical locations might support higher equilibrium
● phylogeography = description and analysis of processes that number of species (carrying capacity)
govern geographic distribution of lineages of genes 2. diversification rate hypothesis = rate of increase in
○ processes include dispersal of organisms that carry the diversity has been greater in the tropics for a long time
genes (past movement of species), and the history by because of a higher speciation rate, a lower extinction
which dispersal and vicariance have determined their rate, or both
present distributions (B) diversification rate might be higher in the tropics
○ can be used to infer history of a populations’ spread 3. time and area hypothesis = most lineages have been
accumulating species for a longer time in tropical than in
extratropical environments
⁕ based on phylogenetic niche conservatism
geographic range limits: ecology and evolution
⁕ tropical areas might be a ‘cradle’ in which new species
arise at a high rate, or a ‘museum’ in which ancient
● species’ geographic distribution results not only from their
lineages persist
ancestors’ history, but also from current factors:
⁕ most lineages originated in tropical climates, and the
○ sexually reproducing species must find mates, must be
relatively few lineages that have evolved adaptations
able to survive physical conditions, find suitable resources
to the stressful temperatures and seasonal fluctuation
(food, habitat), and contend with other species
in food supply typical of the temperature zone are
(competitors, predators, and parasites)
younger that haven’t had time to become as divers →
(C) tropical regions have had more time to accumulate
dispersal limitations species
● border of a species’ geographic range is sometimes set by
unfavorable conditions (e.g. ocean’s edge)
○ this may be a nonequilibrial (temporary) border (e.g.
plants with trans-Atlantic distributions)
● plant species that reproduce by self-fertilization have broader
latitudinal ranges than outcrossing species
2
