Final Flashcards
what is dispersal
movement of organisms from their point of origin
What is dispersion
patial distribution of individual organisms within a local population
does dispersal or dispersion happen more
dispersal occurs more have to look at fossil records for dispersal
What needs to happen for an organism to expand range
Must travel to a new area,
survive harsh conditions during its passage
finally establish a viable colony
What is jump dispersal
Rapid transit of individual organisms across large distances. Happens in a short period
What is diffusion
range expansion that is accomplished over generations by individuals spreading out from the margins of the species range e.g. rabbit Aus
what are the three stages to diffusion
- Invasion and range expansion starts slow
- once established range expands at exponential rate
- range expansion then slows when physical, climatic or ecological barriers are encountered
What is Secular migration
takes a fucking long time and things evolve on route. e.g. camels alpaca lama.
What is Active dispersal (vagility)
movement of an organism from one point to another by its own motility (swimming flying) rather than being carried by another force
What is passive dispersal
movement of an organism from one location to another by a means of a stronger force
What are the different types pf passive dispersal
anemochore- wind dispersal
thalassochore- sea dispersal
hydrochore- water dispersal
anmohydrochore- mixture of wind and water dispersal
brochure- transportation through organisms (digested fruit)
What’s a diaspore
any part or stage in the life cycle of an organism that is adapted for dispersal (e.g. seeds with hooks jellyfish with sails)
What is a barrier
any terrain that hinders or prevents the dispersal of organisms weeds are more tolerant and better at dispersal
what is a physiological barrier and an example
limitation within the body not physically possible. e.g salinity and water temp
what are ecological and psychological barriers
having the ability to disperse but not doing so and physicalshit like mountains
what is a corridor
a route that permits the direct spread of many or most taxa from one region to another. Provides a similar environment to that of the two source areas e.g. land bridges of the maxima
what is a filter
geographic or ecological barrier that blocks the passage of some froms but not others. Often form transition zones between two biogeographic regions
what is a sweepstake route
dangerous pathway for migration potential deadly.island hopping
what are the three things that are needed for dispersal to be successful
habitat selection and a propagule (any part of the organism, or group of organisms that can reproduce the species thus establish a new population.
survival in a new habitat
What is an endemic
a taxon that is restricted to the geographic areas specified. Only live in one place
what is provincialism
coincident occourance of large numbers of well differentiated endemic forms in an area, regional or provincial distinctiveness
what is disjunction
cases in which two or more closely related taxa occur in widely separated regions but are absent from intervening areas. they reflect past events e.g. flightless birds
what are the two reasons organisms are endemic to a location
they originated in that place and never left or they now survive in only a small part of their former range
what is a micro endemic
species that have an extremely restricted distribution, living as a single population in a small area. e.g. devils hole pupfish in a single spring pool
what is a cosmopolitan taxa
organisms that are widely distributed throughout the world
how many truly cosmopolitan species are their
1 humans
what are examples of cosmopolitan species
rats and mice, peregrine falcon , dogs and wolves, killer whales, bats
what are the two types of endemics
autochthonous- having originated in the area in which it presently occurs
allochthonous- having originated outside the area in which it now occurs
what are the two kinds of relics
taxonomic relics- sole survivor of a once diverse taxonomic group. e.g. Aus lungfish
biogeographic relics- are the narrowly endemic descendants of a once widespread taxa
how can you classify endemics by age
paleoendemic- endemic that evolved in the distant past
neoendemic- recently formed endemic species within last 10,000 years
what are the 5 biogeographical regions and where are they
holarctic Asia Europe North America
neotropical-central and south America
Ethiopian- Africa south of Sahara
oriental- Southeast Asia
Australian
what are biogeographic lines
rapid turnover of taxa at the boundaries between regions e.g. lines of Indonesian islands
what is the difference between continental islands and oceanic islands
continental islands- closely related to animals nearby the mainland. often considered of the same species to mainland
oceanic islans- well differentiated from their nearby continents
what are disjunctions
are those distributions in which closely related organisms live in widely separated areas
what process’ took place for disjuncts to occur
- continental drift
- proadly populated then went extinct in all but a few secluded areas
- one lineage dispersed a long distance from area where its ancestors originally occurred
why hasn’t biotic interchange been more complete
barriers, predation, food
what are the two functional groups that follow provincialism
limited dispersal powers and specialised adaptions to a particular habitat
small land birds that are long distance migrants
what is convergence evolution
if physical environ are similar, distantly related organisms
in isolated regions may independently evolve similar adaptations. kangaroo mice
who is Charles Lyell and what did he do
used fossil records to propose earth experienced cycles of global climate. therefore earths surface and its biota are dynamic
what did F.B Taylor do
discovered continental drift but attributed it to tidal movement and solar and lunar shit
who is Alfred wegnar
meteorologist that created the right continental drift theory
what were the initial backlashof continental drift
too many assumptions with no evidence
to many errors 36m compared to 2-12cm
evidence for continental drift
good fit
Gondwanaland shit should be together (fossils glaciers)
how did paleomagnetism help discover the earths past
due to pole flipping rocks with magnetism within would be directed in different ways
what is the great American exchange
animals moving from south to north visa versa due to a land bridge
what advantages did northern forms havein the great american exchange
better migrators, better survivors and spectators and better competitors
during a glacial maxima Pleistocene how much of the earths crust was covered in ice
1/3 2-3km thick
what are the three changes of the earth that may cause glaciation
eccentricity (changes in orbit
obliquity (orbit tilt)
precession (orientation pole wandering
3 effects on non glaciated areas
temp (Wisconsin caused drop of 5 deg)
Shifts in climatic zones (north south)
Sea level changes
triggers of biogeographic dynamics
1-changes in location, extent and configuration of their prime habitat
2-changes in the climatic dynamics and environmental zones
3-formation and loss of dispersal routes
responses from biota to biogeographical change
1-ability to “float” along with their optimal habitat as it changed in altitude & latitude
2-remained & adapted to altered conditions
3-experienced range reduction & went extinct
what is a nunatak
refugia that persisted within or adjacent to the ice sheets (piece of rock)
what were the three refugee during the Wisconsin
Nova Scotia
coastal regions of pacific north west
iceless areas of beringia
what’s a pluvial lake
a lake that id formed now in desert area e.g. great salt lake and lake chad
what is the overkill hypothesis
humans as responsible for off of large herbivores after Wisconsin
arguments against overkill hypothesis
human populations may not have been big enough.
aggressive hunters did coexist with large mammals for a long time
What is Areography
subdiscipline that describes patterns and their processes influencing the sizes, shapes & locations of geographic ranges
what is rapport rule
tendency for range size to increase when latitude increases
what are the three phases of the range size
small large then small to extinction
what did brown and Maur discover
NA birds and mammals North south where as Europe is east west
What is Bergmanns rule
bigger individuals are found farther north due to surface area and mass ratio keep warm
what’s Allens rule
among closely related endothermic vertebrates, those forms living in hotter environment tend to have longer appendages (ears)
what’s glogers rule
dark colours found mainly in tropics. avoid predators
what is species richness
of species in a census (sample) from a geographical region or local area
What is diversity on the local scale
alpha diversity- species richness of local ecological community
beta diversity- the change (or turnover) in spices composition over a small distance
What is diversity on the global scale
gamma- total species richness of a large geographic area. Alpha+beta
delta- comparing species list for large geographic area
what is the peninsula pattern
species richness drops as you travel further down the peninsula
