also called non-coexistence escape or living where herbivores don’t live.
physical body attributes that make the organism difficult or impossible to eat. example: spines or slime.
aka camouflage/blending in
bright warning colors to tell predators of toxicity or harm. very conspicuous.
How toxic does an organisms usually want to be to avoid predators?
Toxic but not enough to kill your predator right away so that others can learn not to eat it.
Batesian vs Mullerian Mimicry
harmless mimic harmful vs harmful mimics harmful. (good for rare species so organsims eat one and learn to avoid all species)
plant secondary compounds that are produced for defense. secondary as in not necessary for life.
Present in high amounts. Effective against generalists & specialists. not highly toxic. more dosage increases response.
low concentrations, not dosage dependent, effective against generalists and toxic in small doses.
inducible vs constitutive defense
only produced when needed vs always present.
what are the 4 components of Darwin’s Theory of Evolution
1) Organisms produce like organisms. 2) Variation exists among individuals and some is heritable. 3) overproduction- populations reproduce faster than environment can support(not all can survive). 4) differential reproductive success- individuals with most favorable characteristics are most likely to survive and reproduce. ** all conditions must be met for evolution to occur.
Common garden experiment
not just for plants. It’s when organisms from different regions are grown all in the same place. often to look at genetic differences.
P. glandulousa plant
Are genetic differents occurring among different elevation plants. Null: if no genetic differences then all plants will grow equally well for each garden. results: differences in growth indicate genetic variation among populations.
To guide the population by removing existing variation. does not generate new variation.
moves a population’s phenotype in one direction.
favors intermediate/average phenotype. centers it.
favors extreme phenotypes. creates a biomodal graph.
beak length for fruit type. Are the differences genetic or induced? by common garden- juvaniles of all populations on same fruit you can see pure genetic differences? and yes there are genetic influences
random changes in allele frequencies. Can remove genetic variation from the population especially if it is small.
mainland population usually has more genetic diversity.
Peter and Rosemary Grant
Finch Studiers yay!
found variation in beak length among seed eaters that was heritable. There was a variability in the success of survival and reproducing. especially evident from 1976 drought. when only larger seeds and thus large seed eaters survived.
3 main life reproduction questions
1) how often do individuals reproduce. 2) how many resources devoted per offspring. 3) how many offspring per reproductive event.
High egg layers tended to die sooner than low egg layers.
If they didn’t produce sperm they lived longer.
Interoparity vs Semelparity
Potential to reproduce many times vs can only reproduce once. Based on balancing juvenile vs adult mortality.
Semelparous vs interoparous Lobelia plant. Why?
In dry valleys it dies sooner so reproduces less. semelparous- dry rock slopes, large inflorescence and seeds vs interoparous- moist valley small flowers and seeds.
What’s the correlation between birth weight and number of offspring?
Negative, as offspring # increase birth weight decreases.
number of bird effs laid at one time
Plants with larger seeds produced fewer of them.
Those larger seeds produced larger seedlings.(higher recruitment)
seed survived and is starting to grow into a young plant, it is a small juvenile beyond a seedling.
What should determine optimal clutch size?
most common clutch should result in the most offspring fledged.
usually lay 7 eggs. When clutch size manipulated to 5-9 7 showed most number of chicks fledged. thus optimal.
Trade off between offspring number and parent survival. parents with extra eggs raised them all but the chicks fledged less, were undernourished and the parents died more.
Why not lay as many eggs as possible?
Because more eggs doesn’t mean more offspring. More eggs can mean fewer resources/offspring, poorer survival rates and more expenditure from parent (like higher morality).
common in variable environments, where popularizations fluctuate or in habitats with little competition.
good with competition.
Trade off between fast and slow organisms.
Fast have higher fecundity, mortality and shorter lives vs slow ones have lower annual fecundity and lower mortality aka longer lives.
Grimes plant life history strategies
Ruderal, stress tolerant, competitive.
Live in highly disturbed environments, with low stress. Have rapid growth & reproduction, large number of seeds and are similar to r-selected.
Stressful environment/low disturbance. Slower growth, highly defended and similar to k-selected.
low stress/low disturbance (aka favorable for many species). Thus strong competitive ability. * in between K & R.
Intra vs Interspecific competition
within 1 species vs among 2 or more species.
indirect interactions, impacts on share resources
direct interaction ex) aggression, territorial defense, or chemical release.
coexistence vs competitive exclusion in paramecia
inhabit different regions of the flask & ate different food vs one does well, other disappears because they are both after the same food.
When resources & space of two species overlap competition occurs with competative exclusion being an extreme overlap.
What barnacles live where?
Chathamalus- higher shore vs Balanus- lives lower down.
Lotka-Volterra Competition model
Look in flashcards
Isocline of zero population growth
Types of resource partitioning
by food size or by micro habitat.
What is a niche?
A set of environmental conditions within which an organism can maintain a viable population size.
Ecological niche/ fundamental niche
optimal niche size in the absence of interspecific interaction.
actual niche size in presence of interspecific competition.
remove a competitor and the species does better/niche widens.
process by which natural selection drives competing species into different patterns of resource use or different niches.
Obligate vs faculitative
organisms dependent on each other vs can survive without each other.
specialist mutualism vs generalist mutualism
only 2 particular species vs multiple species can possibly be involved (although mutualism is always between 2)
Plant & fungal mycorrhizae
typically faculative. mycro- give plant more nutrients and water and get exudates/carbon food in return.
potential benefits of mutualism
increased birth rates, decreased death rates/injury, nutritional benefits, increased equilibrium population densities and raised K for each species.