Geog. 2 Final Exam
Do different types of organisms show differences in range sizes?
Vertebrates > insects & plants Birds > mammals Marine > terrestrial Predators > herbivores
When do you achieve "true domestication?"
When the organism is completely dependent on humans and cannot survive without them
Can organisms disperse by BOTH jump and diffusion at the same time?
Yes they can!?
What is allopatric speciation?
a physical barrier divides one population into two or more populations
How does isolation affect the diversity on islands?
a. Affect species richness b. Closer islands to the mainland have 10x the species diversity of bird species c. Closer they are to the mountain range, the higher diversity d. The farther you are from the mainland, the lower diversity e. Diversity increases on islands because organisms diversify to reduce competition
What were some of the main drivers of the megafaunal extinctions?
a. Climate change b. Comet c. Human impact
What are some global impacts of domestication?
a. Dense human populationsIncreased contact between animals and humans b. increased contact between humans and animals. c. Resulted in evolution and transmission of acute, highly infectious, epidemic disease: "crowd disease" - Measles and TB from cattle - Influenza from pigs and ducks - Smallpox from cattle or camels d. Humans became agents of conquesti. - Concentrated in Eurasia: source 13/14 large domestic mammals
Are species-area curves on islands similar to those on continents? How have they found to differ?
a. Generally they can be b. Larger plots include more species than smaller plots because of random chance in selection of sampling area c. Larger plots contain greater variety microhabitats, resources (niches) d. Tight niche partitioning allows for more species on the island
What are some of the drivers for the loss of natural pollinators?
a. Human disturbance: bees are dying because of habitat loss b. Pesticides c. Parasites and diseases d. Invasion of africanized honeybees
What are some characteristics that increase the potential of an organism to be domesticated by humans?
a. If they can benefit humans b. Animals w a diet that humans can easily supply c. Fast growth rate and short birth spacing (if they multiply easily) d. Docile disposition e. Can breed in captivity f. Follow leader dominance hierarchies g. No panic in enclosures
According to Diamond, 2002, what were some of the possible explanations for the development of agriculture in different regions?
a. Improvement in hunting skills -> overexploitation of large mammals b. Development of tech to collect, process, and store wild food c. Competition among societies for more effective technology d. Human pop growth & more knowledge/workforce e. All areas well suited for farming/herding back then f. Areas were regions where most numerous and most valuable domesticable species were native
What are some biogeographic impacts of domestication?
a. Increase range sizes for selected species (including humans) b. 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 c. 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) d. Significant land-use and land-cover changes (changing land again)
How have human activities affected the rate of extinctions?
a. Increase the rate of extinction bc of contributing to climate change b. Deforestation c. Habitat destruction d. Pollution in ecosystems
Why was the development of agriculture important? What did the development of agriculture allow for?
a. Permanent food source b. Human population explosion: human population settle down increase growth of human population c. Allowed for complex technology to be built d. Sedentary lifestyle (little or no physical activity) e. 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?
a. 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. b. Human population explosion: Use less energy for hunting, more energy for living life c. Increased climate extremes caused humans need to need a more reliable food source d. Megafaunal extinction and dec of big game species e. Inc human occupation in all dif habitats
How has the amount of cropland and pasture changed over the last few centuries? What are some implications of this for natural habitat, globally?
a. Reduction of natural ecosystems overall b. Cropland and pastures have replaced grasses and shrubs significantly & rapid expansion / takeover of grasslands c. Increased cultivation of grazing and crops over time d. Patchwork of different fields
What are some ecosystem impacts when large herbivores went extinct?
a. Trophic cascade, increased plant biomass and diversity of plants, more fuel wood and biomass for fires
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?
a. Wheati. Domesticated in the fertile crescent b. Ricei. Domesticated in Asia c. Maize (corn)i. Domesticated in central america (mexico)
Why are some species more prone to extinction while others persist for millions of years
a.Species may not have genetic diversity to adapt to long-term changes in physical environment caused by continental drift and climatic change b.Chance events i. Limited distribution wiped out by large disturbance c. Diseased. Competition
According to the figures below, California is predicted to have:
a. reduced temperatures. b. reduced precipitation. c. massive increases in species richness. d. massive decreases in species richness.
Does a human share more nucleotide base pairs with a bird or with a fish?
bird
What is a clade?
different species from one same ancestor
Differential changes in phenology can result in a ______ of timing between herbivores and their resource.
geographical shift - Geographical shifts disrupt cycle. Ex. temp changes affect timing of breeding/flowering
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
What is speciation?
the formation of new and distinct species in the course of evolution.
What is some evidence of 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 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?
● 3 main goals ○ Conservation of biodiversity ○ Sustainable use of biodiversity Lab Topics ○ Fair and equitable sharing of the benefits arising from the user of genetic resources ● 2 Supplementary○ Cartagena Protocol ■ International treaty governing the movements of living modified organisms resulting from modern biotech from one country to another ○ Nagoya Protocol■ Fair and equitable sharing of benefits arising from utilization of genetic resources, thereby contributing to the conservation and sustainable use of biodiversity
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
What is a problem with chloropleth maps?
● Dot maps extrapolated using info about environmental requirements and conditions of area being mapped to show where a species could be ● Problem: Just shows the whole range, not density
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○ No longer sufficiently abundant and reproducing to ensure survival ● Threatened: likely to be endangered in foreseeable future ● How to identify: ○ Consider total population size, rate of mortality, reproductive rate, rate of overall population decline, frequency of disturbances that decrease population size
What does evolutionary potential have to do with conservation? Why should we care?
● Evolution (long-term) combined with immigration (short-term) contributes to species additions ● Need to include evolutionary potential in conservation
Which two island groups or regions were very important for developing important evolutionary concepts, by Darwin and Wallace, respectively?
● Galapagos island, Ecuador ● Australia and asia
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 ○ Best indicator of endangered species
What is the difference between in-situ and ex-situ conservation? How are the species being protected?
● In-situ: have a reserve and monitoring species to make sure they're ok (inside their own habitat) ● Ex-situ: take creature into zoo and try to make them reproduce (monitoring them outside of their habitat)
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 ● They might develop gigantism, evolve larger bodies because don't need to hide from predators, more resources and space for themselves, can last longer without water or food with larger bodies, or dwarfism due to less resources on crowded islands ● Lose antipredator defenses ● Have highly specialized niches to reduce competition ● Can nest on the ground instead of in a tree (don't have to worry about predators)
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
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 ● Can we really apply model from oceanic islands to fragments continental habitat?
Which tend to have more species- a large or a smaller island? Species-Area Curves?
● Larger plot, more species ● Larger plot contain greater variety ● As islands increase in size, species number and richness increase
What is the difference between observational data and empirical data? Can they be used in conjunction?
● 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 ● Yes, they are used in conjunction (MAXENT)
What is range collapse? Define, and give an example from class.
● Range collapse: geographic distribution severely reduced ● Best indicator of endangered species ● Example: Panda, Javan rhinoceros
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○ Tropics have a lot of resources and lots of niches ■ Higher diversity within smaller area ○ Higher latitudes organisms spread out ● Shorter and cooler growing season so need larger range for sufficient NPP to support species ● Wider tolerance to daily and seasonal climate variation allow for greater niche breadth ● Lower diversity (less competition)
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 ○ Ex situ: botanical gardens, zoo ○ In situ: in natural environment, protect habitat ○ Challenge: preservation of natural genetic variability ● 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) ○ Not only endangered species but all known and unknown species ○ Method of island biogeography approach ○ If you protect one species or biodiversity of a few species but not their habitat or food source or other organisms they depend on and interact with, they can still go extinct easily
What is the story with the spotted owl? Where is it being used as an umbrella species?
● Umbrella species: important ecological function ● Spotted owl in Pacific NW was being affected by logging. People stopped logging and not only saved the owls but a lot of other species
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 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 •Basis of agriculture = cultivation of domesticated plants and animals for human use. How can they help us?
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 - Immigration: new species come through dispersal and colonization - Extinction: removes some old species but they are replaced by new arrivals - 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 - As richness increases, extinction and emigration inc while immig dec
What is the difference between the background extinction rate and a catastrophic extinction rate? Please know the numbers for these given in class (Still need numbers)
- 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 - Ex. During late Permian (250 mya). 50% animal families lost
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
How does Krakatoa exemplify some biological and non-equilibrium effects of the Theory of Island Biogeography?
- Krakatoa has a lot of bird species which exemplifies the biological and non-equilibrium effects because increased distance from mainland makes it harder for most organisms to get to the island except flying animals - Species richness equilibrium was achieved for flying animals but was harder for non flying animals
How can historical factors affect the diversity on islands?
- Land-bridge islands: Geologic history affects species diversity because land bridges that appear and disappear can let in different species that could migrate and evolve there but then disappear and cut off other species - historical attachments to land masses can allow certain species and ancestors to be all over the world, get cut off, and evolve differently - 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 - Historical theories weaken over very long periods of time
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 - They also migrate earlier when there isn't enough food
What was the megafaunal extinction? Where and when did it occur?
- Massive extinction of mammals over 50 kg mostly in north america but also other places - Megafaunal extinction: 13-14 kya
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 - Few species with very wide ranges, which indicated strong competitive pressures
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 - Closeness to mainland can decrease extinction bc recruitment of individuals of the same species can lower change of species going extinct - Target area effect:- Target area effect explains that size affects amount of immigrants to organisms, larger islands are easier targets for active dispersers and passive dispersers to immigrate to
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
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
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
Which region has seen the largest increase in ectotherm metabolic rate?
- Warmer climates - 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) - I.e lizards will run into trouble because they are more likely to starve in high tropics
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
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)
Roughly how much has the Earth warmed over the last century?
0.74 degrees Celsius
What are the 6 main human drivers of extinction rates? i.e. how do humans influence evolutionary development of other species?
1. Landscape changes 2. Removal of predators 3. Hunting pressure 4. Pesticides, antibiotic, pollutants 5. Domestication, breeding 6. Agriculture, artificial selection
Have we been very successful with a large proportion of domesticated varieties of wild flora and fauna? Why or why not?
14/148 terrestrial mammals & 100/20,000 plant species have been domesticated
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 is pastoral nomadism?
A form of subsistence agriculture based on herding domesticated animals. Constantly moving land areas by the seasons so their herds can grazeGroups organized around herding domesticated animals, supplementing meat and milk instead of hunting and gathering
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)
Be able to 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 it called when unrelated species in different places evolve to have similar traits and fill similar niches?
Convergent evolution
Why might humans be considered "corn's koala"?
Corn is in everything!We have manipulated corn to be consumed by humans and animals in all products even though we think its not
Are dog breeds many different species or a single species? How do we know?
Dog breeds are all a single species!!!All dogs can mate with one another and create fertile offspring and pass down their genes (species)
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
What islands tend to have fewer or more endemic species than the mainland? Why might this be?
Endemism increase as islands becomes more isolated because they evolve separately and evolve to fit their environment and not fit anywhere else
What is a local extinction?
Extinction only in one area, but not globally
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 is the founder effect?
Founders effect: loss of genetic variability when new population founded by small gene pool - important in species colonizing remote location - The species that get through are the founders of future generations
Which two states of the USA are dealing with the most loss of biodiversity?
Hawaii & California
Generally, do lower or higher trophic levels need larger ranges?
Higher need larger ranges
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 reserveA single undivided reserve is better than a number of small reservesIf divided, reserves should be spaced equally from another, not linearly If reserves are linear, they should be connected with corridorsIr reserve is small and isolated, it should be circular and not linear
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 is the story with sheep and goat domestication?
Hunted by humans and selectivity choosing which ones to breedModern goats and sheep are smaller in size and have different horns and coats (more wool) than wild ancestors.
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 bc it increases immigration rates and large reserves decrease extinction rates
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 Ex: Eucalyptus can NOT cross from Australia
What sorts of traits did humans select for in wolves to come up with our common dog?
Loyal, non-aggression towards humans, docile
Did agriculture develop in one single spot or in several places around the world? Are these agricultural hearths known for their agriculture today?
Multiple spots around the world at around the same time Dif times dif places around the world (fertile crescent, mediterranean, se asia, cent amer, andes) (10,000 BC-2,000 BC) Now not known for agriculture
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 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
Was North America or South America more diverse when their plates collided?
N America was more diverse
Why might proximity to other reserves play a role in the conservation within a single reserve site?
Need proximity to other source areas for rescue effect
What did the air pollution and soot have on the natural selection of the moths? Why?
Normally, white moths would blend into white treeIndustrial rev: trees would be covered in black soot so black moths would blend in White moths got eaten because they stuck out on soot covered trees
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. Lush 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. b. 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.
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?
On the edges!! i. 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 b. Can cross waters to diff regions
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 are some human causes of habitat degradation?
Pollution, invasive species
What is domestication?
Process of training plants and animals to be reliant on humans for survival while giving benefits to humans
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
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
What types of fossils can be seen at the La Brea Tar Pits?
Saber tooth cat, giant ground sloth, condors, wooly mammoths
What do we see with the human selection of Brassica species for certain traits?
Selected for different types of plants we like. Original ancestral plant for broccoli cauliflower, brussels sprouts, kale, cabbage, collard greens. Related from thousands of years of humans selectively choosing to breed ones with each other that have desirable traits.
What is genetic drift?
Small genetic changes over time. The distribution of new genes and phenotypes over time in new generations.
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 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
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 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? causes a change in the genetic shift of the population which causes evolution to suit themselves best to their environment over time
Generally, what are the 3 things that can genetically separate out different species?
# of chromosomes, # of genes, and location of genes (??) Chromosomal, allele, and genome diversity
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) b. Connected 2-3 million years ago
How is convergent evolution different from allopatric speciation?
Allopatric speciation is animals from a similar genetic family that evolve differently bc of a barrier whereas convergent evolution are animals from different genetic families who evolve with similar characteristics
How is convergent evolution different from parallel evolution?
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 with a common ancestor
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? I would likely provide some of the graphs from class in this, like the figure on the right:
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
Using the figure below, what is it showing in terms of butterfly migration over time? (Check out the "notes" section of this lecture's powerpoint)
Changes in the range of the speckled wood butterfly in Great Britain since 1940. Data are plotted on a 10x10 grid and a colored cell indicates more than once the population observed during 1940-1969 (blue) or 1970-1997 (red).
Who proposed the mechanism o f evolution, not the original idea?
Charles Darwin
What is 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 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?
Environmental change 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
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
In the example of green and brown beetles, how can that mutation influence natural selection and genetic drift?
Genetic drift: When the beetles reproduced, just by random luck more brown genes than green genes ended up in the offspring. In the diagram at right, brown genes selection and genetic drift? occur slightly more frequently in the offspring (29%) than in the parent generation (25%). b. Natural selection: Beetles with brown genes escaped predation and survived to reproduce more frequently than beetles with green genes, so that more brown genes got into the next generation.
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)
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
Can evolution occur in one generation? Why or why not?
No 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 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?
Not sure but: 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
What kind of organisms have the highest probability of jump dispersal?
Organisms that can fly Organisms that can cling to animals/ humans Or can float on water
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 b. 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 speciesb. 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)
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
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 decre
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
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) - Term for animals transporting seeds = zoochory - Epizoochory and endozoochory fall under the Hitching Dispersal method, which is a type of zoochory
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
What are the definitions of barriers and corridors to dispersal? Can you provide an example of each? b?
a. A barrier is a physical or biogeographical block that stops organisms from dispersing between different land areas i. 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) b. 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 i. Corridors between two sides of landscape divided by a highway, land bridges, strip of land without forest c. Idk ab the taxa question or what taxa isi. 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 d. In terms of animal movement, a corridor allows mammals to move freely between areas, whereas a sweepstakes route is the result of a freak occurrence.
What is the difference between background extinction and mass extinction?
a. Background extinction: slow extinction over time of individual species, overspecialized animals die and naturally doomed species go extinct b. Mass extinction: large amounts of species and huge percentages of pops all dying and going extinct in one short time period
What is an endemic species? Does endemism tend to be high or low on islands?
a. Endemic species is a species that is only found in that location b. Endemism tends to be high on islands b/c it is isolated from the mainland i. Islands are hot houses for evolution and have primary succession + random dispersal and evolve separately to be endemic
What does the "sweepstakes" event mean in terms of dispersal? Is it an easy thing to do?
a. 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 -Colonization by chance b. 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 c. Sweepstake: arrive via web-flying (ballooning) -> progression rule of island colonization - S. Routes: rarely successful dispersal (by chance), but import 4 diversification flora/fauna
Where did Darwin conduct much of his research? What kind of critter did he study in depth there?
a. Galapagos island (Ecuador today) b. finch
What are the "four observations" that can guide natural selection?
a. High reproductive capacity b. Limits on population growth / carrying capacity c. Inherited variation of differing traits and genetics d. Differential reproductive success
How can island chains act as filters? Give an example from class
a. 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 is the difference between genotypic and phenotypic variation? Is phenotype driven purely by genetics, or does something else influence phenotype?
a. Phenotypic variation: dif in physiology, anatomy, behavior of species / individuals (overall differences in appearances), what is expressed b. Genotypic variation: genetic differences and makeup of how we look, form and behavior and differences in alleles and genetic traits, what your genes actually are c. Phenotype is often a result of genotypic variation but is strongly influenced by the environment
Does evolution show a general trend towards increased complexity?
a. Sometimes evolution creates more complexity but also sometimes it makes things more simple, there is no such thing as "perfect adaptation" because environmental change is more permanent and affecting than evolutionary changeb. b. 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. c. Some increases in body size but others not, increase in complexity isn't always good
How do islands and mountains act as "stepping stones" for dispersal?
a. 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 is one potential ecosystem impact with a loss of a species?
a. Trophic cascade (trophic level crash) if a keystone species is lost b. Affect predator and prey levels Keystone species can cause trophic cascade (ex. Sabertooth cats had no prey to hunt and [i think condors were overpopulated bc mammoths weren't preying on them anymore]
What is archipelago speciation, and how does it vary from adaptive radiation? What were the examples used for this?
a. When species become geog separated from each other b. 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 c. Example of archipelago speciation: Galapagos mockingbird (geographically isolated) d. Ex of adaptive radiation: finches, honeycreepers, niche based in same area
What happened to Krakatoa? Why is it an interesting case study?
a. bird species pretty high b. 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 c. It's an island in indonesia that saw a lot of dispersal of plants and animals after the eruption so we can use it to understand darwinism
What sort of time scales are the Milankovitch Cycles on? Decadal, centennial, tens of thousands of years?
- 26,000 years to 100,000 years - Tens of thousands of years
What phenomenon occurred in the finches in the Galapagos and the Cichlid fish in Africa?
- Adaptive radiation: development of many species from one ancestor - Fill all available niches in colonized region - Ex. Islands or lakes - Finches did that in the Galapagos (original ate seeds then evolved diff species for insects and other stuff) - Cichlid fish: 300s of species evolved in 12,000 years within lakes in Africa
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
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 - Decreased water availability - Drought also makes trees more susceptible to death by beetle infestations, but I think water scarcity is greatest risk
Where do we expect plants to move as temperatures increase? 2 ways/ directions
- Higher latitudes & higher elevations th - 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 (basically up and north / away from equator)
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
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, Multiple impacts - 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] - Iridium later at boundary late cretaceous/tertiary (KT) 65 mya]
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 d=
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 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 - Migration to the poles and up in altitude along a mountain range
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) - Terrestrial NPP increases in tropical ecosystems - NPP will decrease with droughts - There will be more NPP in the western hemisphere than southern
Is the warming of the planet happening evenly across the globe? If not, which part of the Earth is warming the most quickly?
- No, not even 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? - 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 - Polar regions have warmed the most, especially the Arctic because of sea ice melt
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?
- Not sure ab answer: 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. - I think the key point is that the plants had to move to higher elevations - California's Santa Rosa Mountains? The average elevation of the dominant plant species increased by 65m
What is parallel evolution? What is a potential example? We gave 1 in class
- 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)
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 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
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 is a bottleneck in population genetics and how can this affect genetic variation, genetic drift, and speciation?
- The bottleneck is the idea that of a certain amount of genetic variation in a species, only a fraction will move to a different area. - event where pop is drastically reduced and the survival group forms a parent class that has a dif proportion of genetics and traits so it makes a new generation that's very dif from old past generations- Definition: decreased genetic diversity resulting from decreased population size- Genetic drift: the changing of genes and traits over time due to natural selection and different traits being passed on in different amounts to the following generations- Speciation is more likely to occur at edges of species range small range of genetic variability - More rapid speciation in small, isolated populations (bottlenecks) - Species develop to fill maximum niche space** genetic variation will be dif from parent generation, genetic drift will occur in newer generations, speciation will occur faster
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) - Drought makes the trees more susceptible to being attacked as well
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 the Industrial Revolution 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 time of year is warming predicted to be greatest, summer or winter?
- Warming greatest in winter & high latitudes
Using the figure below, which region and which tree species is suffering the largest current tree mortality?
- Western region, Jack Pine
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) -- acacia plants & ants
What does the following figure indicate?
- White bars are 1963 elevational range data from Whittaker and Niering study, whereas the black bars represent 2011 elevation data from the current study. - This figure indicates that ranges of these species have decreased from 1963 to 2011 because the black bars are not as long as the white bars. It also shows that species have shifted to higher elevations because the black bars do not extend below 3000 feet, as the white bars do. - In summary, species in 1963 had a broader geographic range across low to high elevations than those same species in 2011
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) - basically animals at boundaries branch off into their own species - genetic drift and natural selection -Allopatric speciation: borders create different species (mountain range or water body) a→ b, c ; c→ d, e - in allopatric speciation, physical barriers make it impossible for members of the groups to interbreed with one another.
What are four of the types of evidence used to support the theory of evolution?
1. Fossil record (shows how organisms evolved over time) 2. Comparing anatomy (similar anatomies = relatedness) 3. Biogeography (why organisms are where they are) 4. Molecular biology (shows relationships on a molecular level/genes and enzymes and nucleotide basis)
What are four different strategies that organisms might utilize for eventual reproductive isolation?
1. Mutations 2. Geographic barriers 3. Chance dispersal 4. Geological events (vicariance)
