Bio Geography

the movement of an organism away from its point of origin

active involves locomotion by the organism itself

durring passive, the organism is transported by gravity, wind, water, or other organisms

the dispersal of a species across a geographic area that is not occupied by the species

successful long distance jump dispersal events

overall, pretty rare, but with 10-100 million species on the planet, a "one in a million chance" does occur

Geographic routes with low probability of successful dispersal

overall, pretty rare, but with 10-100 million species on the planet, a "one in a million chance" does occur

the expansion of the range of a species along a discrete front

organisms dispersed by wind

organisms dispersed by other organisms

Geographic features that promote dispersal and colonization

avenues of dispersal and colonization that are not equally favorable for all species

species that are particularly well suited to long distance dispersal and successful colonization

the stage in the life cycle (a plant seed for example) part of an organism (a piece of marram grass which can develop a new set of roots and grow into a full sized grass plant), or group of organisms (a male and female rabbit of matting age) that is required to establish a new reproducing population

EX) male/female (minimum requirement for pass on their genes)

chains of closely distributed islands or discrete areas of similar habitat, such as mountains surrounded by low elevation deserts, that aid in the dispersal of some species

• Once you get to the island, you need to be able to
• “establish” yourself

Getting there isn’t good enough

Genetially controlled changes in physiology, anatomy, and behavior that occur to a clade over time.

Micro refers to evolution at the scale of the species.

Macro refers to evolutionary changes viewed at higher taxonomic units such as genera and families.

the development of similar morphological or physiological traits in unrelated species living in geographically seperated regions that have similar environments

EX) Australia/Africa/U.S. rats

• similar phenotype, completely different genotype
• fill similar niche
• similar phenotype due to similar niche in the similar environment

occurs when geographically isolated populations derived from the same ancestor evolve into morphologically and physiologically similar descendent species

EX) gecho in carribean

• species from a common ancestor, and they fill same niches.
• these evolve into different species, and jump dispersal since they cant have the same niche in the same environment

stochastic changes in the genetic composition of a population that occur over time as new genes arice via mutation and other genes are lost through change variations

the process by which the genes for genetically controlled traits become more common in a poulation over time because individuals with those traits are reproductively more successful than other individuals.

a slow and gradual process of evolution during which new taits arise by mutations and traits which infer greater reproductive success are selected for and eventually become dominant over many generations

• a model of evolution in which new genotypes and species arise as small isolated populations or populations at the edges of the main species population.
• These small populations increase and bery rapidly become dominant when environmental changes cuase them to be better adapted to new environment conditions

the formation of new species by geographic isolation

the development of new species within the same geographic area as the parent species

the idea that populations founded by a very small number of indivuduals generaly contain a small subset of the total genetic variability of the main population and are prone to allopatric speciation

• the development of many species from a single founding species.
• the new species evolve to occupy the different range of habitats and use the different resources that are present in the region in which adaptive radiation occurs.

geologic events or environmental changes that divide the ranges of species into geographically isolated distributions.

nonobservable differnces in the genes between different species or members of the same species.

observable differences in the physiology, anatomy, or behavior of different species or individuals of the same species

the loss of all individuals of a species, genus, family, or order.

may be local or global

occurs when the loss of an important prey species causes further evosystem disruptions and extinctions because of the loss of food for higher predators

states that because all of a species' competitors are continually evolving and becoming more competitive, if a species cannot evolve quickly enough to keep pace with the evolution of competing species, it will become extinct

the movement of terrestrial fauna that occurred following the establishment of the Isthmus of Panama

having a global geographic distribution

having only a few geographic distributions

a geographic boundary dividing beographic regions

supercontinental areas taht contaim similar flora and fauna

continental and superconitnental areas that contain similar flora and fauna

subcontinental areas that contain similar flora and fauna

Book

Didn’t believe in evo before the beagle

Invited onto the beagle as the ships naturalist, but also to hang with the capt

Jumping from one port to the next, collecting data

Gets to the Galapagos

Finds different this and that on the same islands, and on different this and that on different islands

Darwin didn’t write down where he found the finches at lol

GEOGRAPHY mattered!!!!

Became a geographer eventually

Book

Alfred Wallace was the first to see variation

When collecting his insects, he would get more than one.

Did it to sell for money, not cause he didn’t believed in species topology;

Darwin got only one cause of species topology (collect one, collect all)

Starts to believe in evolution

Sends his idea about evolution to Darwin;

Darwin was like, WTF!! hahahahaha

Some loser just selling crap for money could steal his thunder

Each present a paper

Darwin released his book the next year, while Wallace was still in Malaysia hahahaha sucker!!!!!

evolution is genetially controlled changes in physiology, anatomy, and behavior that occur to a clade over time

clade is the lineage of different related species that arise from a common ancestor

Micro refers to evolution at the scale of the species

Macro refers to evolutionary changes viewed at higher taxonomic units such as genera and families

natural selection is the process by which the genes for genetically controlled traits become more common in a poulation over time because individuals with those traits are reproductively more successful than other individuals

• micro evolution EX)
• mosquitoes evolving resistance to DDT
• whiteflies evolving resistance to pesticides
• gonorrheal bacteria strains evolving resistance to penicillin
• HIV strains evolving resistance to antiviral medicines

macro evolution EX)

Genetic effects that lead to speciation include: Variation

• Variation comes from mutation
• Comes from parents
• allopatric speciation is the formation of new species by geographic isolation

sympatric speciation is the development of new species within the same geographic area as the parent species

The top three man made reasons for extinction include habitat loss, exotic species, and explotation.

Some types of extinction include deforestation and isolation/fragmentation

Deforestation

Whatever habitat you had there is gone

Less biodiversity

Fewer resources

More competition

Fewer large animals (trophic pyramid)

Insects the same, but after that, forget it

Huge reduction as you go down in size

Isolation

Areas in between areas of forest become like barriers causing no jump dispersal

This process is called fragmentation

Large forest being broken up into smaller fragments

Species Risk Factors (if you are this, you are more at risk to go extinct)

More specialized

Low genetic variability

Cant adapt to changes

Size

Need more food if you are bigger

Carnivore even worse cause there are bunch of animals below you than just a herbivore that eats the very botton of the trophic pyramid (plants)

Low reproduction cycle

If you only have offspring once every 5 years, you will be more at risk of going extinct than if you have 100 offspring every year

Abiotic Factors

Changes that are non living

Storms

Climate change

Fires

• active involves locomotion by the organism itself.
• during passive, the organism is transported by gravity, wind, water, or other organisms

a great example of range expansion is cheat grass. cheat grass was accidentily introduced into NorthWestern America (started off in only the state of Washington), and through a series of jump dispersal, aided by passive dispersal of its seeds in feed and with live stock, it spread throughout the west (Washington, Oregon, Idaho, California, Nevada, Utah)

a corridor is a Geographic features that promote dispersal and colonization

a filter is an avenue of dispersal and colonization that is not equally favorable for all species

Barrirs leading to filters.......

Can be physical or ‘psychological’

Psychological meaning:

Barrier a species can pass, but choses not to

EX) Small rodent will go the long way that is covered than go the fast way that is not

Corridor

A potential dispersal route that is not limited in any way

Everything in ‘zone a’ can get to ‘zone b’

Central America is NOT a corridor because some make it and some don’t; to be a corridor, all would have to be able to make it

today, geographers try to create a corridor for animals; very hard to do

need the right habitat

need lots of space

need multiple life cycles

one makes it this far, the next generation makes it further, etc

in the real world, there are NO corridors; instead, we have FILTERS; filtering out some animals

EX) island jumping

only way to get pass the filter of water is jump dispersal (the water is the filter, filtering it, to where some animals make it and some dont)

in some cases, plants use wind/birds to carry seeds

how do animals get there?

Swim

frogs catch rides as well

Duck lands in a pond

Pick up water, in the water is eggs

Odds are way against you due to new habitat

As you get further away from home, the number of those that make it drop FAST; meaning less biodiversity

Success upon arrival is so low that some routes are called 'sweepstakes routes"; meaning the chance of success is the same chance as somone winning the lottery or sweepstakes

The best way for a species to survive include being eury everything...euryhaline (saline), euryphagous (food), eurythermic (temp)...the more wide their range is, the better they will be able to adapt into a new environment

Endeminism is when a species, genera, or family is restricted to one or a few geographic regions

Cosmopolitanism is when a species, genera, or family has a global geographic distribution

In general, endemism is the common state for land plants and animals, while true cosmopolitians are rare.

cosmos rare because:

• eury in every category is very hard to do
• generalist able to survive in many areas
• good competitors and colonizers

• top one:
• seed being dispersed by wind
• most seeds (500) are being dispersed close to parent
• number of seeds droped drops dramatically from about 10-50 meters
• once hit 50 meters, only about 40 seeds are being dropped, and once you hit 100 meters, only about 10 are being dropped
• bottom one:
• seed being dispersed by an animal
• about 80% of seeds are being dropped at 0-20 meters
• number drops dramatically from 20-50 meters
• only about 10 percents of seeds are droped past 50 meters, and only about 5 percent of seeds are dropped past 100 meters

Outcome:

difference isn’t really huge

most are falling near parent

doesn’t really change whether it is caused by wind or animals

hard for jay to fly a long way while carrying a nut

also, the further you get from home, the more the environment is going to change

TIPPING POINT is around 50 meters for both with only a tiny portion transported more than 100 meters away

House Finch and Jump Dispersal

Introduced to Long Island

spread from Massachusetts to North Carolina

slowly diffusing over time through jump dispersal and the establishment of small disjunct (distinct) populations in advance of the main diffusion front

home still the same place, just migrating out further

Don’t go from one place to one right next to it; it 'jumps' to a further one away

Yarrow Plants

they grow from a near sea level (0 meters lol) to elvations of over 3600 meters!!!!!

• tall in the lowlands (70cm)
• small in the highlands (20cm)

low stature allows them to survive at high elevations because it keeps the flowering heads protected from frostbite and closer to the warm ground surface

height decreasing with elevation

drop in elevation causes higher height, just not as tall as original

What causes the difference? Is it the genotype or phenotype (the environment)?

Only one way to find out:

Plant the seeds somewhere else

If you move it to the west or east and it’s the same size, genotype (moved it to a different geographic location and nothing changed...must be the genotype)

If you move it to the west or east and it changes, phenotype (environment) (could still be genotype as well, but you do know now that the environment has the ability to change it as well ;)

Answer in this case is a little bit of both; big chunk was pheno though; when they transported the small ones to lower elevation, they stayed around 20 cm

Adaptive Radiation

def of AR --> the development of many species from a common ancestor to fill all of the available niches in the colonized region

utilize different niches to take advantage of different foods

all evolved from same ancestor

in order to survive, they evolved different niches

fish eat on separate food

different mouth mutation

• small mouth for zooplankton
• sharp mouth for picking invertebrates off vegetation

birds eat on different flowers

different beak mutation

• small, thick beak for eating fruit and seeds
• sharp beaks for prying bark apart to find insects
• long slender beak to obtain nectar

if optimum range becomes bad range:

opt range def --> Range where most of the species stay dut to some geographic limiting factor

Some natural phenomena changes the optimum range into an unlivable range

You either get extinction, move to the sides, or two completely different optimum ranges

Showed pic in class, but not in book...WTF!!!!!

Darwin’s finches:

Short beak lives on this island

Med beak lives on this island

Large beak lives on this island

All three can spread out on the entire island, but dont so neither go extinct

Short/med beak lives on this island

All beaks lives on this island

These two scenarios break up the land on their islands