Geog 2 Final Exam Review
How does the environment come into play with natural selection and evolution?
The environment shapes and affects which species, populations, and individuals will survive according to the traits they have that are best suited for them to survive in that environment, basically the environment causes natural selection by making it hard for certain organisms to survive and others to do well, which causes a change in the genetic shift of the population which causes evolution to suit themselves best to their environment over time
How has climate change altered the mountain pine beetle? What is happening to their reproduction?
The mountain pine beetle has thrived because of climate change: climate change has caused range expansion of the pine beetle to more areas & has caused the flight/attacking season to be 2x as long, bc of warming beetle pops are having 2 generations per year / 2 life cycles which is doubling their pop and dec the health of all Pinus trees (which they attack)
Why do we not think the rate of climate change now is not solely due to natural causes?
The natural causes of climate change have been solar variability and sunspots, milankovitch cycles of the earth changing tilt / shape of orbit over thousands of years which causes changes in how the earth gets insolation long term, & orbital cycles, BUT the earth was cold during the Maunder minimum, grew warmer, then colder, then warmer again after the Industrial Revolution which is because IR caused an unprecedented amount of GHGs in the atmosphere and the rate of warming has been faster than ever before, the GHG are more than ever before, and we should be in a cooling period according to history but we're at our warmest yet and quickly increasing in temperature
What are two potential issues or points of contention with the Equilibrium theory of biogeography?
Theory ignores human impact on immigration and emigration (predation, pesticide poisoning, land use/land cover change Theory doesn't address small island effect because there aren't enough resources to support large enough populations to drive extinction rates & islands can be small enough that resources and habitat sizes don't matter
What is the theory of island biogeography? Be able to explain why a near, large island might harbor more species than a small, far island.
Theory says that proximity to mainland and size of island affects immigration rates Closer islands to mainland have better and more jump dispersal success to the island Larger islands have more species because they can support more animals with more habitat and resources and niches available Large near = most species, small far = least species Species turnover highest for small, near islands bc new species arrive and outcompete old ones / large far have lowest turnover bc its hard to get there and once they get there its easy to survive
How are the majority of tree species responding to climate change in terms of distribution?
They are spreading further up North, since the temperatures there are getting warmer and more habitable for them. Higher latitude tree species are losing habitat area & land while most trees are gaining a wider distribution of habitats But, individual tree mortality has increased so even though there's more trees in higher latitude areas, the trees are dying due to droughts
How do islands and mountains act as "stepping stones" for dispersal?
They're closely distributed land masses of similar vegetation and climate where organisms can hop from one to another, as you disperse out you have less species the farther away you get from main area
What are three ways we can characterize the extinctions at the end of the Pleistocene?
Time-transgressive Taxonomically limited (mostly mammals) Size-selective (mammals > 50 kg) 33 genera large mammals extinct
What is one potential ecosystem impact with a loss of a species?
Trophic cascade (trophic level crash) if a keystone species is lost Affect predator and prey levels
What are some ecosystem impacts when large herbivores went extinct?
Trophic cascade, increased plant biomass and diversity of plants, more fuel wood and biomass for fires
What are the two ways animals can transport seeds? What is the term for this kind of dispersal?
Two ways: endozoochory (animal eats a seed and poops it out), epizoochory (burs or seeds catch onto the animal and are accidentally dispersed)
Do different types of organisms show differences in range sizes?
Vertebrates > insects & plants Birds > mammals Marine > terrestrial Predators > herbivores Higher trophic levels need larger ranges
Warmer temperatures have been associated with larger OR smaller body size of endothermic animals?
Warmer temperatures associated with smaller body size of organisms Colder places have larger organisms bc they can keep more heat in internally (rabbit vs polar bear)
What time of year is warming predicted to be greatest, summer or winter?
Warming greatest in winter & high latitudes
What are the two main questions you must ask when designing reserve placement?
What is the minimum area needed to preserve species or set of species? What is the best spatial configuration of reserve areas?
What 3 domesticated crops are the dominant food sources worldwide? Where did these three crops get domesticated- i.e where was their wild ancestor found naturally?
Wheat- fertile crescent rice- asia maize- central am.
What is archipelago speciation, and how does it vary from adaptive radiation? What were the examples used for this?
When species become geog separated from each other Dif from adaptive radiation because in adaptive radiation they split due to niche overlap and resource partitioning / diversification in the same geographic region whereas in archipelago they split bc geog barriers Example of archipelago speciation: Galapagos mockingbird (geographically isolated) Ex of adaptive radiation: finches, honeycreepers, niche based in same area
In some regions, butterflies are emerging earlier than the flowering of herbaceous plants. Why is this an issue?
When the butterflies are arriving / emerging earlier than the plants are flowering, it leaves the butterflies with no food to eat and they therefore starve
When do you achieve "true domestication?"
When the organism is completely dependent on humans and cannot survive without them
What is co-evolution? Can you give any type of example?
When unrelated species evolve similar traits bc of symbiosis or biological interactions, basically they evolve to work together and help each other / match their needs or be similar (orchid flies) (yucca trees)
What are some competitive advantages angiosperms have compared to gymnosperms? How has this affected the distribution and abundance of gymnosperms over time?
angiosperms comp adv. bc more efficient vascular system, ovaries and pollen grains better protection from desiccation Gymnosperms do better in cold places and high elevation
What is a disjunct distribution, and what are four reasons for them? Be able to explain one of the examples in depth
geographic range divided into 2+ geographically separate parts Caused by disersal (jump), climatic (cooling ranges and changes in vegetation) Geologic and evoluntionary factors
What is the founder effect?
loss of genetic variability when new population founded by small gene pool
Differential changes in phenology can result in a _____ of timing between herbivores and their resource.
mismatch; geographical shift
Can evolution occur in one generation? Why or why not?
no bc The same traits/ characteristics has to be passed down from multiple generations and become the main traits in the species in order for it to become a new species or changed species and be considered evolution
What is a living fossil? Give an example
organism from a long long time ago but is still alive today!! Ancient organism (stasis) bc the branch of species still exists and didn't evolve into a new species even if it did evolve (barely evolved) Ex: horseshoe crab, coelacanth, ginkgo tree
Distinguish between phyletic extinction and true extinction.
phyletic extinction: when species go extinct bc they evolve into species that are better competitors / basically just evolve into new species (horse species and early human species - how humans have evolved into a new species and our ancestors are extinct) True extinction: loss of a genus/species with no successors (complete loss of genes)
What were some of the major changes during the last deglaciation since the last glacial maximum? How could these impact biogeography and dispersal of organisms?
temp rise, ice sheet melt, sea level rise Biogeographic barriers rise and disappear (impact biogeography and dispersal)
Convergent evolution
when unrelated species in different places evolve to have similar traits and fill similar niches
Generally, what are the 3 things that can genetically separate out different species?
# of chromosomes, # of genes, and location of genes (??)
What are two major impacts on humans of domestication of wild critters?
(1) geographic spread of plants and animal species used by humans (some become invasive) (2) geographic spread and population growth of humans over the past 10,000 years
What is the difference between homologous traits and analogous traits? Can you identify them if we provide a figure(s) from the lecture powerpoint?
- Homologous traits: share common ancestor, result of divergent evolution - bird, dog, human, etc all having the same bone from an ancestor - Analogous traits: result of convergent evolution - developing to have similar anatomy like how bats and birds both have wings
1. Roughly how much has the Earth warmed over the last century?
0.74 degrees celsius
What three things determine modern biogeographical regions?
1. present locations of biogeographic barriers 2. history of continental plates 3. evolutionary history of modern animal and plant families
What sort of time scales are the Milankovitch Cycles on? Decadal, centennial, tens of thousands of years?
26,000 years to 100,000 years
How many mass extinctions have there been in the past? What is the main driver of the current one scientists think we are experiencing? Why?
5 mass extinctions? Main driver today is humans
What does the term "Biotic ferry" refer to, and why? Roughly when did this occur?
90 MYA India separated from Gondwanaland and collided with Asia
What are the definitions of barriers and corridors to dispersal? Can you provide an example of each? Are barriers the same across all taxa?
A barrier is a physical or biogeographical block that stops organisms from dispersing between different land areas environmental barriers, biological, natural/human caused, ocean barrier, land, mountains in tropics (mountains are bigger barriers in tropics than they are in high latitude areas), elevation (at tropics there's little seasonal variation while at temperate areas there's more variation and a bigger difference between elevations, explains restricted distribution of mountainous species in the tropics) Corridor: environmental conditions that allow for dispersal between geographically separate locations, natural or human caused, there's biogeographic harmonization which is basically similar species at both ends of the corridors, corridors facilitate dispersal and important to conserve fragmented landscapes Corridors between two sides of landscape divided by a highway, land bridges, Barriers are not the same across all taxa. A barrier for one taxa can be a corridor for another. Taxa are just like the grouping of organisms into family or species
What is a bottleneck in population genetics and how can this affect genetic variation, genetic drift, and speciation?
A population bottleneck is an event that drastically reduces the size of a population. -- decreased genetic diversity resulting from decreased population size The bottleneck may be caused by various events, such as an environmental disaster, the hunting of a species to the point of extinction, or habitat destruction that results in the deaths of organisms
What is speciation?
A population/ancestor evolves overtime to become multiple new species
What was the Great American Interchange, and which species were able to travel each way?
A time when species from South and North America spread into both continents, the isthmus of Panama filtered it so that only some could make it across, land masses of S and N America connected after being separated and had the central american land bridge and a marine barrier and terrestrial corridor w filter so that only 10% of mammals exchanged - the filter changed over time due to climate change (savanna to forest to glacial savanna etc) North America more diverse
Understand the difference between relative time and absolute time. Which is easier to achieve, and which is more accurate?
Absolute time: actual number of years before present (accurate) Relative time: Sequence of events - what happened in what order (easier)
What phenomenon occurred in the finches in the Galapagos and the Cichlid fish in Africa?
Adaptive radiation: development of many species from one ancestor
How does isolation affect the diversity on islands?
Affect species richness Closer islands have 10x the species diversity of bird species Closer they are to the mountain range, the higher diversity The farther you are from the mainland, the lower diversity Diversity increases on islands because organisms diversify to reduce competition
What happened in Africa roughly 20 million years ago?
Africa collided with Eurasia: landbridge facilitated: Southward migration ancestors primates, camels and zebras from Nearctic and carnivores (lions, jackals) from Palearctic Northward migration elephants and mammoths
After the KT mass extinction event, what were two main drivers of the explosion of mammal diversity?
Allopatric speciation Adaptive radiation
How is convergent evolution different from allopatric speciation?
Although they're both evolution in different geologic places, convergent evolution is when two different species evolve similar bc of their environment while parallel evolution is when two similar species evolve in the same way because they're in geographically separated but similar environments
In which taxonomic group of organisms has the timing of spring events changed the most in response to climate change?
Amphibians have a greater shift towards early breeding times than other taxonomic groups (more than 2x as fast as trees, birds, butterflies)
explain anagenesis and cladogenesis
Anagenesis: successive speciation from one single species line (a species turns from one species to another to another over time without branching off into many different species, just one species changing bc of microevolution) Cladogenesis: macroevolution / adaptive radiation where one species becomes multiple dif species
What is the difference between anemochory and hydrochory? Can they occur in conjunction?
Anemochory = seeds carried by wind Hydrochory = seeds carried by water Can occur together / as a result of each other
Which tend to have more species- a large or a smaller island? Species-Area Curves?
As islands increase in size, species number and richness increase
How do immigration and extinction function on islands? How do they affect the total number of species or species turnover?
Assumption that species richness of island is in equilibrium with processes of immigration and extinction Rate of immigration will decrease as more species are on the island (as species richness increases) bc there's fewer resources and habitat available Rate of emigration increases then though bc there's a higher chance of random extinction and competition when there's more organisms on the island
What is the difference between the background extinction rate and a catastrophic extinction rate
Background extinction rate: continuous extinction for plants and animals through geological time Avg: 1 plant family/4 my for past 400my Catastrophic extinction rate: discrete episodes of very high rates of extinction
What is the difference between background extinction and mass extinction?
Background extinction: slow extinction over time of individual species, overspecialized animals die and naturally doomed species go extinct Mass extinction: large amounts of species and huge percentages of pops all dying and going extinct in one short time period
What is allopatric speciation?
Basically when a species gets geog separated from the parent species and turns into two dif species because they go through separated evolution
Explain how a dandelion is an example of a Supertramp.
Can disperse thousands of miles away from their parent plant, wide climatic tolerances, mature quick & disperse fast & outcompete native species Supertramp = species well suited for rapid dispersal and successful colonization, generalist niche, fast growth rate
What did we see when we looked at Caribou numbers and when foliage was emerging?
Caribou used to be able to time when to have their calves in accordance with when their high nutrient foliage would flower, BUT the warming of spring temperatures caused the foliage and plants to grow increasingly earlier than usual while the caribou are triggered to have their calves by day length (which stays the same) so the plants are arriving earlier and the calves are coming barely earlier which causes the calves to come too late to the high nutrient foliage and calf mortality inc while calf production dec
What was the difference in Central America over glacial and interglacial periods over the last 3 million years? What did it affect in terms of dispersal?
Central american landbridge / filter started as an open savanna / forest, during glacial phase became a savanna, then during interglacial phase became a dense forest Dense forest = filter and less transfer, savanna = open and lots of movement / transfer
How have modern barriers changed over time? Give an example
Changed over time with sea level changes Landbridge mainland Asia/Malasian archipelago deep channel remained between Borneo/Sulawesi Bering strait landbridge
What is a clade?
Clade = dif species from one same ancestor
What are some implications of species migrations during climate change of the quaternary period?
Co-evolutionary relationships among many species must be fairly weak Species must be able to survive some range of climate variability
What were the three main goals of the UN International Convention on Biological Diversity? What were the two main supplementary agreements added to it since 1992?
Conservation of biodiversity Sustainable use of biodiversity Fair and equitable sharing of the benefits arising from the user of genetic resources Supplementary: Cartagena: International treaty governing the movements of living modified organisms resulting from modern biotech from one country to another Nagoya: Fair and equitable sharing of benefits arising from utilization of genetic resources, thereby contributing to the conservation and sustainable use of biodiversity
What is pastoral nomadism?
Constantly moving land areas by the seasons so their herds can graze Groups organized around herding domesticated animals, supplementing meat and milk instead of hunting and gathering
Convergent Evolution
Convergent evolution: similar species of different ancestral backgrounds develop in different places but develop to be similar bc of the similar environment (ex. Desert; winged species, marsupials vs placentals)
What is a corridor? Why is it important in conservation?
Corridor connect 2 regions of the same animal (land bridge) Allows a species to cross different regions and spread
In terms of animal movement, a _________ allows mammals to move freely between areas, whereas a ____________. _______ is the result of a freak occurrence.
Corridor, sweepstakes route
What is a cosmopolitan species? What is an example?
Cosmopolitan species are found across the globe. Rats, dogs, rabbits Cosmopolitan: widely distributed family, genera, or species
Does evolution show a general trend towards increased complexity?
Darwin saw progression from simple to complex life forms, but now species show evolutionary reduction from complex to simple bc greater complexity causes less reproductive success
What are some global impacts of domestication?
Dense human pops Increased contact between animals and humans resulted evolute and transmit of crowd disease like measles and influenza humans become agents of conquest
Did agriculture develop in one single spot or in several places around the world? Are these agricultural hearths known for their agriculture today?
Dif times dif places around the world (fertile crescent, mediterranean, se asia, cent amer, andes) (10,000 BC-2,000 BC)
What is the difference between diffusion and jump dispersal? What types of critters are likely to do either?
Diffusion: when there is a slow movement or dispersal of seeds/plants/animals, basically when there's a slow spread into adjacent land and they slowly spread their geographic range Likely to do it: plants that disperse seeds close to parents and rely on next generation to expand range, ex. Trees and slow growth organisms Jump Dispersal: when new populations establish themselves far from the original range limits of the species and its not a gradual dispersal, this is how islands are populated Likely to do it: wind blown seeds and flying animals
Dog/ Sheep and goat Breeding
Dogs all single species and know this bc they can reproduce with one another Sheep and goat hunted and selectively chosen which ones to breed, now smaller and different horns
What is a problem with chloropleth maps?
Dot maps extrapolated using info about environmental requirements and conditions of area being mapped Problem: Just shows the whole range, not density
In North America, what is the greatest risk of warming to trees?
Droughts increase and cause more tree deaths (water stress) OR loss of tree habitat because trees need colder climates but their habitat areas will be too warm for them to survive in
What is the edge effect?
Edge effect: changes in environment (physical) conditions at border range/habitat Disturbance wind-throw in forests Increased light, drying out Increased invasion risk
Where is speciation most likely to occur: in the region with the highest density of individuals of the same species, or on the edges of their ranges?
Edges- Most likely to deal w more competition on the edges and more niche diversification so they need to adapt and evolve to be more successful
What are some of the factors used to characterize a species as endangered or threatened, to identify them before they go extinct?
Endangered: at risk of extinction throughout all or portion of range Threatened: likely to be endangered in foreseeable future identify: Consider total population size, rate of mortality, reproductive rate, rate of overall population decline, frequency of disturbances that decrease population size
What is an endemic species? Does endemism tend to be high or low on islands?
Endemic species is a species that is only found in that location Endemism tends to be high on islands b/c it is isolated from the mainland Islands are hot houses for evolution and have primary succession + random dispersal and evolve separately to be endemic
Do islands tend to have fewer or more endemic species than the mainland? Why might this be?
Endemism (only one location) increases as islands becomes more isolated because they evolve separately and evolve to fit their environment and not fit anywhere else
What are the two great "engines" of biogeography, and the three fundamental processes of biogeography?
Engines: evolution (biologic engine) & plate tectonics (geographic engine) Processes:dispersal, extinction, evolution
Which is faster, the rate of environmental change or evolutionary change? What implications might this have?
Env change faster- Environmental change might slow down evolution and cause more extinction, organisms can't evolve fast enough to keep up w the environmental changes - animals will change to dif envs faster than they will evolve to try and keep up
What is some evidence for long-distance dispersal events?
Eurasian dandelion is a long distance dispersal example; it's now found on every continent besides Antarctica thanks to humans
What does the "sweepstakes" event mean in terms of dispersal? Is it an easy thing to do?
Event hits land and causes species to spread drastically Its a type of rarely successful progression and dispersal of a species to a new island in which they colonize the island Very rare type of dispersal but important for species to move far and spread, basically lucky and rare they even made it to the island so it's hard to do
What is a local extinction?
Extinction only in one area, but not globally
Why might higher taxonomic levels be more cosmopolitan? i.e. families versus species
Families and genera can include a wide variety of species with greatly different niches, so can occupy wide variety environments (although each species is more restricted) Long distance dispersal and colonization may be successful by one species but not others Species evolve and diverge more quickly than entire genera and families Extinction may affect one species but not all within a genus or family Basically families can have way more species and be found everywhere while it's harder for a species to be found everywhere
Where was agriculture first developed around 8,500-10,000 years ago?
Fertile Crescent
Why is isolation important in speciation?
Fill in a bunch of empty niches and adapt to the environment there and evolve, if you're isolated then you will evolve differently and adapt to different circumstances and niches
What type of organisms did mammals evolve from, and roughly when?
First mammals evolved from reptiles (Triassic) 220 million years ago
What is an angiosperm? During which period of time did angiosperms evolve and speciate to high levels of diversity?
Flowering plants Expanded from 1% flora to > 50% flora between 100-65 million years ago
What are four of the types of evidence used to support the theory of evolution?
Fossil record (shows how organisms evolved over time) Comparing anatomy (similar anatomies = relatedness) Biogeography (why organisms are where they are) Molecular biology (shows relationships on a molecular level / genes & enzymes & nucleotide bases)
Are species-area curves on islands similar to those on continents? How have they found to differ?
Generally they can be Larger plots include more species than smaller plots because of random chance in selection of sampling area Larger plots contain greater variety microhabitats, resources (niches) Tight niche partitioning allows for more species on the island
As populations decrease, what happens to the genetic variability?
Genetic diversity and variability decrease because there's less options and organisms to have different genes - have a higher risk of extinction
What is the biological concept of defining what a species is? Why is a mule not officially a species?
Group of individuals that can/could breed to produce fertile offspring A mule can't breed with another mule to produce a fertile offspring (hybrid speciation: 2 species mate to produce offspring that's reproductively isolated from parent species)
Where are gymnosperms dominant in the world at present? What are three reasons for this?
Gymnosperms still dominate high elevations and high latitudes N. Hemisphere Evergreen (desiccation not big problem in cool temps)
What are some types of habitat loss? Which is the most severe?
Habitat destruction: complete loss Habitat fragmentation: reduction in size and loss of connectivity Habitat degradation: disruption of ecosystem processes and ecological function Range collapse: geographic distribution severely reduced- indicator of endangered species
What are the "four observations" that can guide natural selection?
High reproductive capacity Limits on population growth / carrying capacity Inherited variation of differing traits and genetics Differential reproductive success
Where do we expect plants to move as temperatures increase? 2 ways/ directions
Higher latitudes & higher elevations As temperature increases, warmer species will gain more land area while cold-habitat species lose land, SO species will move higher in elevation and closer towards the poles
What is conservation biogeography? What are 5 main approaches to/goals of it?
How spatial distribution or temporal patterns and historical events affect present abundance and potential conservation of biodiversity A large reserve is better than a small reserve A single undivided reserve is better than a number of small reserves If divided, reserves should be spaced equally from another, not linearly If reserves are linear, they should be connected with corridors Ir reserve is small and isolated, it should be circular and not linear
What are some of the drivers for the loss of natural pollinators?
Human disturbance: bees are dying because of habitat loss Pesticides Parasites and diseases Invasion of africanized honeybees
What is selective breeding? How can humans influence evolutionary development of other species?
Humans choosing which characteristics and traits to reproduce in an organism Increased range size for selected species, pick specific traits for the species to evolve into and have for the overall species over the next few generations
What are some characteristics that increase the potential of an organism to be domesticated by humans?
If they can benefit humans Animals w a diet that humans can easily supply Fast growth rate and short birth spacing (if they multiply easily) Docile disposition Can breed in captivity Follow leader dominance hierarchies No panic in enclosures
According to Diamond, 2002, what were some of the possible explanations for the development of agriculture in different regions?
Improvement in hunting skills -> overexploitation of large mammals Development of tech to collect, process, and store wild food Competition among societies for more effective technology Human pop growth & more knowledge/workforce All areas well suited for farming/herding back then Areas were regions where most numerous and most valuable domesticable species were native
What is the difference between in-situ and ex-situ conservation? How are the species beign protected?
In-situ: have a reserve and monitoring species to make sure they're ok Ex-situ: take creature into zoo and try to make them reproduce
What are some biogeographic impacts of domestication?
Increase range sizes for selected species (including humans) Changes in genetic makeup of populations Reduced diversity Persistence of otherwise lethal or debilitating genes artificial selection of specific genes Breeding new hybrids Transgenic material Significant impact on ecosystem distributions (we've changed a lot of land to provide grazing areas for our animals so there's less forests etc) Significant land-use and land-cover changes (changing land again)
How have human activities affected the rate of extinctions?
Increase the rate of extinction bc of contributing to climate change Deforestation Habitat destruction Pollution in ecosystems
What are the two main fields of theories as to why the dinosaurs went extinct? Within those fields, what are some of the dominant theories? What do the two fields agree on?
Intrinsic gradualists: volcanism, continental drift Extrinsic catastrophists: asteroid impact (65 mi diameter crater), Proposed crater: chicxulub in Yucatan but recent evidence suggests this crate predated K/T boundary both agree on: Global climate change played some part: warm, mild Mesozoic to cooler, more varied Cenozoic Env. Changes, likely from massive terrestrial disturbance: [dust and soot: aerosol cooling, acid rain and poisonous gases, co2 and h2o ghg: warming] Extinction marine and terrestrial vertebrates and inverts: also affected marine autotrophs [heavy metal pollution oceans, dust and charcoal: block sunlight]
How can island species differ from mainland species? Why might they evolve in this way?
Island species may lose the ability to disperse because they no longer have a threat on that island (less predators) - don't want to leave or disperse and move around if they are comfy without predators - may lose ability to fly Can develop: gigantism, less antipredator defenses, specialized niche or nest on ground instead of tree
How can the concept of an "island" be used on terrestrial systems?
Islands are defined as isolated habitats and regions so they don't always have to be plots of land in the ocean, terrestrial islands are fragmented habitats like mountaintops, patches of land from fires or fragmentation, hurricane torn habitats, and trees falling down can isolate mini habitats
Why are islands a hotspot for evolutionary ecologists?
Islands are hotspots for biodiversity Can look at evolution closely overtime on this contained area Islands show us how biodiversity can explode and how geography changes and drives biodiversity
How does isolation or connectivity drive similarities or differences across regions?
Isolation over time causes adaptive radiation where one species turns into many different species or one species becomes endemic to that area (causes rapid evolution from ancestral species into many new forms to specialize themselves and use dif resources to reduce competition) Connectivity of land masses over geologic time causes homogenization and widespread occurrence of the organism
What are the 6 main human drivers of extinction rates? i.e. how do humans influence evolutionary development of other species?
Landscape changes Removal of predators Hunting pressure Pesticides, antibiotic, pollutants Domestication, breeding Agriculture, artificial selection
How can we potentially apply the Equilibrium Theory of Biogeography to the field of conservation biogeography?
Large reserves near other reserves would have the highest species richness
Which do you think might be better in the SLOSS debate? Single large reserve or several small reserves? Why?
Large single area may not include all habitat diversity of small several strategically placed reserves Species richness increase is non linear All eggs in one basket if have a single large reserve
In the bird named great tits, what has increased warming resulted in? earlier migration schedules, earlier egg laying, greater mortality, OR larger body size?
Laying their eggs earlier every year bc the warm temps have signaled them to lay their eggs too early
What is Wallace's line? Where is it located, and which sorts of critters viewed it as a barrier? Which were able to cross?
Line barrier between Asia and Australia that represented a barrier of which species couldn't cross and were inherently different (asian or australian), animals more divided by land barrier than plants Some bats were able to cross, more flora than fauna can cross, many bird species and larger terrestrial mammals can not cross
What is the difference between local and global extinctions? Can you give an example of each?
Local extinction: bison which used to have a wide range but are now isolated to small pockets (extinct in Texas but not fully extinct as in non existent) -Global extinction: no individuals of a species are found anywhere (wooly mammoth)
What was the megafaunal extinction? Where and when did it occur? Drivers?
Massive extinction of mammals over 50 kg mostly in north america but also other places Megafaunal extinction: 13-14 kya Driven by climate change, comet and human impact
Which region has seen the largest increase in ectotherm metabolic rate?
Metabolic rate increases exponentially with temperature increases Metabolic rates increased more quickly in tropics and temperate areas than in the arctic or cold areas = tropic/warm area metabolic rates increased (increased the need for food for animals in tropical regions, causes them to be more likely to starve and less energy for tropical animals to reproduce)
What is the difference between micro and macro evolution?
Micro: within populations or species - changes in gene frequency from 1 generation to the next but can probably interbreed Macro: within larger taxonomic groups - descent of dif species from 1 common ancestor over many generations - evolution above species level, creates many dif species and speciation
What effect is warming predicted to have on migration behavior?
Migration and arrival dates are happening earlier and sooner Birds will depart for migration earlier and return earlier
How did species respond to periods of glaciation and inter-glacial periods?
Migration was a primary species response, with range shifts measuring hundreds to thousands of kilometers
What are some of the reasons most species have range sizes on the smaller end of the histogram?
Most species are specialists Relatively few have broad generalist niches Majority survive by being adapted to narrow set of conditions and outcompeting others
What is a mutation, and how can it lead to evolution?
Mutation is a rare change in genetics, must happen a lot to change alleles in 1 generation and therefore change occurs over a long time and leads to evolution by changing genes
What are four different strategies that organisms might utilize for eventual reproductive isolation?
Mutations Geographic barriers Chance dispersal Geological events (vicariance)
What are two things that can result in reproductive isolation? What can happen after reproductive isolation?
Mutations and geographic barriers can result in reproductive isolation After reproductive isolation the two evolve into their own new species, further differentiation from natural selection or genetic drift
Was North America connected to Eurasia or South America for longer on the geologic time scale?
N America & Eurasia connected for most of history
Overall, what is the net trend of NPP due to climate change
NPP increased globally bc of warming (NPP increased at tropics, coast, mid latitudes and decreased at higher latitudes)
Is the warming of the planet happening evenly across the globe? If not, which part of the Earth is warming the most quickly?
Not even; Cold regions have warmed the most, winter months warmed more than summer months, minimum temperature ranges have risen so that the minimum temperature is warmer than ever before while maximum temperatures have risen barely
What is the Oasis Theory and what later data supported or disproved it?
Oasis theory: theory talks about during the last glacial maximum it was a lot cooler and wetter during that time period. Less vegetation and plentiful game so it wasn't hard for hunters and gatherings to get their nutritional needs met. By the end of the holocene it got warmer and drier and would restrict ecological human productivity close to water sources. Humans would cluster in these oases and would just settle there. Data proved by pollen records proved this theory to be false and the opposite in which it was drier during last glacial maximum and that after the climate was wetter and warmer which allowed people to settle.
What is the difference between observational data and empirical data?
Observational data (field surveys) Natural history collection specimens Published in journal papers, monographs, etc Empirical modeling (extrapolating from what is known) Seeks non-random association between Species known presences Environmental variables describing ecological landscape
What is a biogeographic relict?
Once had a large distribution but now are narrow endemics
How can island chains act as filters? Give an example from class
Only some organisms can pass to the next island, if they can handle the environment and can get transportation so as you go out, you have less species and there's overall less species in the furthest island
What kind of organisms have the highest probability of jump dispersal?
Organisms: fly, cling to animals, float on water Can do both at same time
What is parallel evolution? What is a potential example?
Parallel evolution is when geographically separated populations from same ancestor develop into similar species bc of similar environments (anole lizards on different islands) (have similar morphology and develop similarly because of similar environments)
What is peripatric speciation? How does it differ from allopatric speciation? Be able to identify the figures.
Peripatric speciation: accelerated speciation & genetic divergence at the outskirts of the population through founder effect in peripheral speciation a,b,c,d,e (no barrier, just outer edge of species range)(break off of same branch) animals at boundaries branch off into own species
Why was the development of agriculture important? What did the development of agriculture allow for?
Permanent food source Human population explosion: human population settle down increase growth of human population Allowed for complex technology to be built Sedentary lifestyle (little or no physical activity) Development of stratified societies (people categorized by race, class, gender)
What are some of the "why's" as to why humans developed agriculture compared to Hunter-gathering societies?
Permanent food source: So that they can settle down and have a stockpile of food, don't have to go chase down their food for every meal. Human population explosion: Use less energy for hunting, more energy for living life Increased climate extremes caused humans need to need a more reliable food source Megafaunal extinction and dec of big game species Inc human occupation in all dif habitats
What is the term for the timing of seasonal activities of plants and animals?
Phenology = seasonal timing of organism's activities (ex. Hibernation, reproduction, flowering, migrating)
What is the difference between genotypic and phenotypic variation? Is phenotype driven purely by genetics, or does something else influence phenotype?
Phenotypic variation: dif in physiology, anatomy, behavior of species / individuals (overall differences in appearances) Genotypic variation: genetic differences and makeup of how we look, form and behavior and differences in alleles and genetic traits Phenotype is often a result of genotypic variation but is strongly influenced by the environment
What is the difference between phyletic gradualism and quantum evolution?
Phyletic gradualism: slow and gradual process where mutations cause new traits which help or hurt due to natural selection and cause some to survive better which causes those traits to become dominant over time and causes slow evolution into the new species Quantum evolution: rapid appearance of new species in the fossil record
What is the difference between phyletic gradualism and punctuated equilibrium?
Phyletic gradualism: slow but constant rate of change, steady line of incline changes and new traits forming and slow transition into new species Punctuated equilibrium: most of the time there is little to no evolutionary change, everything is stagnant followed by short spikes of speciation and evolutionary change, then no change then small short events of change, (steady then a short spike)
What sort of predictions does the International Tundra Experiment provide for vegetation expansion or contraction in the Arctic?
Plant communities will change rapidly, vegetation expansion in the arctic and inc shrub cover & height, dec moss & lichen cover, inc soil respiration and inc NPP and plant productivity
Are the floristic and zoogeographic provinces the exact same? Why or why not?
Plants and animals have very different behaviors and different climate and environments that suit them each differently Plants (florisitc provinces): holarctic, neotrophical, paleotropical, south africa, australian and antarctic animals: nearctic, palearctic, neotropical, ethiopian, oriental, australian
How can historical factors affect the diversity on islands?
Possible decline in species diversity which causes species relaxation which occurs when a region or land bridge gets cut off from mainland and species diversity goes down
What happened to Krakatoa? Why is it an interesting case study?
Primary succession post volcanic eruption, species brought by anemochory and hydrochory and tree cover then inc, then zoochory organisms came and it was basically an evolutionary outdoor lab
What is domestication?
Process of training plants and animals to be reliant on humans for survival while giving benefits to humans
What was the climate generally like on the planet during the quaternary period?
Progressive cooling and regular swings from glacial to interglacial periods
What are some of the drivers of the loss of biological diversity within tropical rainforests?
Rainforests destroyed for human settlements, plantations, oil, and mining, home to millions of species but many are endemic, evolution can't keep up w human change and habitat loss
According to Rapaport's Rule, where is range size largest- near the equator or at higher latitudes? How about at the base of a mountain or as you move up in elevation? Why?
Range size increases with latitude or elevation Trophics lots of resources and small niches, high lats more spread out
What types of events could cause a catastrophic extinction?
Rapid climate change, impact meteors on earth's surface, changes in chemistry of ocean or atmosphere, cooling due to volcanic eruptions, unknown?, anthropogenic global change Catastrophic extinctions: Permo-triassic cretaceous-tertiary(64-66 mya, separated age of dinosaurs from age of mammals) megafaunal extinction (13,700 ya, N America, 50% mammal species> 32 kg and all >1000 kg went extinct)
What happened to elephant seals in terms of genetic variability?
Reduced genetic variation bc of bottleneck -1890s: human hunting reduced pop. to 20 individuals present day: 30,000 individuals reproduced by those 20 so their genetic variation is very limited
How has the amount of cropland and pasture changed over the last few centuries? What are some implications of this for natural habitat, globally?
Reduction of natural ecosystems overall Cropland and pastures have replaced grasses and shrubs significantly & rapid expansion / takeover of grasslands Increased cultivation of grazing and crops over time Patchwork of different fields
What are the rescue effect and the target area effect?
Rescue effect: distance from mainland affects species diversity by controlling immigration bc short distance has more immigration and possibility of species being rescued by more immigrating to that area and saving the dwindling population - immigration affects extinction by influencing competitive exclusion and helping them be more competitive Target area effect explains that size of island affects amount of immigrants to organisms, larger islands are easier targets for active dispersers and passive dispersers to immigrate to
What happened to the plant species in the Santa Catalina Mountains in Arizona due to the effects of climate change? Or in California's Santa Rosa Mountains?
Santa Catalina Mountains: mean rainfall dec & temp inc so most of the abundant species shifted up the mountain range and grew in a narrower range higher up the mountain.
What is genetic drift?
Small genetic changes over time, the distribution of new genes and phenotypes over time in new generations
Why does extinction risk change with island size?
Smaller islands have higher risks of extinction because they have fewer resources and habitats, can't support large populations or a large amount of species so there's a higher likelihood of extinction from small physical disturbances and competitive exclusion
Why are some species more prone to extinction while others persist for millions of years
Species may not have genetic diversity to adapt to long-term changes in physical environment caused by continental drift and climatic change Chance events (wipe out by large disturbance) Disease Competiton
What is the "Red Queen Hypothesis" and how does it relate to evolution and extinction?
Species must constantly evolve adaptations to survive Evolutionary arms race between predator and prey where both must keep adapting evolving and running in the evolutionary race just to survive Over specialization: increase extinction bc species relies on one food source: evolutionary trap
What is species relaxation? How might it occur? Where does it occur fastest?
Species relaxation is when there's a decline in species diversity It occurs when a region (like a land bridge island) gets cut off from large island or mainland and the species diversity then goes down Occurs fastest on small islands
Did species respond as a whole community and migrate, or as individuals? What impact did this have on the composition of communities?
Species responded individualistically to climate change; as a result, novel communities emerged with not previous modern counterpart
Which do you think is better or more effective: species-based conservation, biodiversity-based, or habitat-based? Why?
Species-based conservation: goal is to preserve identified species (zoo, botonical garden, protection for rhinos in africa) Biodiversity-based: preserve species richness of an entire ecosystem, and biological interactions (goal of island biogeography approach) Habitat-based: conserve entire biological and physical environment (ecosystem)
How does sympatric speciation differ from allopatric speciation?
Sympatric speciation is different bc it's speciation within the same geographic area but has reproductive isolation due to temporal barriers (like dif life cycle timing, flowering timing, mating at day or night timing), behavioral barriers (dif mating rituals), & chromosomal changes that cause no reproduction w others
What is natural selection
Tendency of better adapted individuals w better survival traits and genes best suited for their env to survive and reproduce while those w worse traits die, causes evolution Mechanism proposed by Darwin, research in galapagos on finch
Why is the Arctic fox declining in numbers? What is happening to their climate and competition?
The arctic fox is declining in numbers because they are the northest, coldest fox but their southern boundary is limited by competition with the red fox. Because of climate change, the red fox is expanding into their territory and outcompeting them because there is no colder climate for the arctic fox to retreat into so the arctic fox decreases in population.