Exam 1 Flashcards
ecology
the scientific study of the abundance and distribution of organisms in realtion to other organisms and environmental conditions
- the study of how/where/why organisms make their “houses”
- study of ecological systems– how they work and how they affect each other
environmental science
a broader, interdisciplinary field, incorporating ecology, chemistry, physics, geology, and sometimes even sociology and policy
- how does science affect humanity’s environment
environmentalism
a philosophy geared toward environmental protection and long-term survival of humanity on earth
individual
-survival and reproduction
- the unit of natural selection that
- the most fundamental unit of ecology
population
- population dynamics
- the unit of evolution
- individuals of the same species living in a particular area
- boundaries can be natural or political
community
- interactions among species
- all populations of various species living together in a particular area that interact or could potentially interact
ecosystem
flow of energy and matter
- one or more communities of living organisms interacting with their nonliving physical and chemical environments
- includes atmosphere, water, soil, and living things
biosphere
global processes
- all ecosystems on Earth
- distant ecosystems are linked together by exchanges of wind and water and by the movement of organisms
species
individuals that are capable of interbreeding and producing fertile offspring
individual approach
to understand how adaptations or characteristics of an individuals morphology, physiology, and behavior enable it to survive in an environment
ways to measure populations
- geographic range (extent of land or water in which a pop lives)
- abundance (total number of individuals)
- density (number of individuals per unit area)
- change in size
- composition (makeup in terms of age, sex, or genetics)
population approach
examines variation in the number, density, and composition of individuals over time and space
community approach
understand the diversity and interactions of organisms living together in the same place
predation/ parasitoidism
+/-
parasitism
+/-
Herbivory
+/-
competition
-/-
mutualism
+/+
commensalism
+/0
ecosystem approach
describes the storage and transfer of energy and matter
biosphere approach
examines movements of energy and chemicals over the Earth’s surface
apparent digestive efficiency
relative proportion of energy absorbed by gut
production efficiency
relative proportion of ingested energy used for growth
proximate hypothesis
addresses the cause of immediate changes in individual phenotypes or ecological interactions
ultimate hypothesis
address the fitness costs and benefits of a response
manipulative experiments
where a hypothesis is tested by altering a factor hypothesized to be the cause of a phenomenon
trestment
the factor that we want to manipulate in a study
ccontrol
a treatment that includes all aspects of an experiment except the factor of interest
experimental unit
the object to which we apply a manipulation
replication
the number of experimental units per treatment
randomization
a requirement for manipulation experiments; every experimental unit must have an equal chance of being assigned to a particular treatment group
natural experiments
an approach to hypothesis testing that relies on natural variation in the environment to test a hypothesis
mathematical models
representations of a system with a a set of equations that correspond to hypothesized relationships among the system’s components
- often tested with natural or manipulative experiments
adaptations
characteristics of an individual’s morphology, physiology, and behavior that enable it to survive in an environment
environmental challenges are the agents that cause…
selection for adaptations
specific heat
the energy required to raise water temperature by 1 degree celcius
density of water
highest density at 4 degrees C
- above and below this, density decreases
- density of water prevents water bodies from freezing solid during winter
viscosity
the thickness of a fluid that causes objects to encounter resistance as they move through it
- water has a high viscosity
- streamlined bodies are important for fast movement through water
water as a solvent
- water can dissolve many substances which makes them accessible to organisms
- polar; negative oxygen end of one molecule is strongly attracted to the positive hydrogen of another
- water attracts charged atoms, which causes many substances to dissolve
homeostasis
an organisms ability to maintain constant internal conditions in the face of a varying external environment
solutes
dissolved substances in water
semipermeable membranes
membranes that allow only particular molecules to pass through; reduces free movement of solutes
osmosis
movement of water across a semipermeable membrane
osmoregulation
mechanisms organisms use to maintain a proper solute balance
hyperosmotic
tissue solute concentrations are higher than surrounding water
hypoosmotic
tissue solute concentrations are lower than surrounding water
freshwater fish are
hyperosmotic
water balance in animals
- behavioral= hunts at night
- physiological= loops of Henle
- nitrogen= metabolic waste product, can form toxic ammonia (terrestrial animals rarely have enough water to excrete NH3 safely)
matic potential
potential energy generated by the attractive forces between water and soil
field capacity
maximum amount of water held by soil against the force of gravity
cohesion
mutual attraction of water molecules; allows water to move up through xylem cells
transpiration
the process by which leaves can generate water potential as water evaporates from the surface of leaf cells
cohesion-tension theory
the mechanism of water movement from roots to leaves due to water cohesion and water tension
- low water potential from transpiration creates tension that draws water up through the xylem against gravity and the high osmotic potential of root cells
stomata
small openings on leaf surfaces that are points of entry for CO2 and exit points for water vapor
guard cells
open and close each stomata
C3 plants
get rid of O2 by keeping stomata open to prevent photorespiration
-lose a LOT of water this way too
C4 plants
uses PEP carboxylase to help get CO2 to Rubisco. CO2 is concentrated in bundle sheath cells to improve efficiency
- less photosynthesis
- more energy/space used in process
CAM plants
similar to C4 plants but gas exchange happens at night, and no bundle sheath cells used
- lower water loss
- slow photosynthesis
- slow growth
what happens when you turn up the heat
- proteins and other biological molecules become less stable, may not function properly, and may denature
- fats become fluid with heat, and stiff with cold temperatures
Q10 value
a ratio of a physiological process rate at one temperature to the rate of that process when the temperature is 10 degrees C cooler than
negative feedback
the action of internal response mechanisms that restores a system to desired state, or set point, when the system deviates from that state
thermoregulation
the ability of an organism to control the temperature of its body
homeotherms
organisms that maintain constant temperature
poikilotherms
organisms that do not have constant body temperatures
endotherms
organisms that can generate metabolic heat
ectotherms
temperatures determined by environmental conditions
blood shunting
when specific blood vessels shut off so less of an animal’s warm blood flows to cold extremities where heat would be lost
countercurrent circulation
conserves heat by positioning arteries that carry warm blood away from the heart alongside veins that carry chilled blood from the extremities back to the heart
blood and water flow…
in opposite directions so that the concentration of O2 in water is always greater than the concentration in blood
glycerol and glycoproteins
chemicals present in some animals that prevent freezing by reducing strength of hydrogen bonds or via supercooling
phenotype
an attribute of an organisms behavior, morphology, or physiology
- genes interacting with environment
fitness
survival and reproduction in a given environment
phenotypic trade-offs
a situation in which a given phenotype experiences higher fitness in one environment, whereas other phenotypes experience higher fitness in other environments
phenotypic plasitcity
the ability of a single genotype to produce multiple phenotypes
- when environmental variation results in phenotypic trade-offs, natural selection will favor the evolution of phenotypic plasticity
- if spatial variation is not common, a single phenotype will be favored
reversible plasticity
appears when environmental conditions change, often within an individual’s lifetime
- in most cases, individuals retain the ability to change their features for most of their lives
irreversible plasiticity
occurs when an organism adjusts the timing of a life history transition in response to environmental circumstances
- these are traits that, once expressed, are not altered regardless of how conditions may change
- appears when environmental conditions are less likely to change drastically within the lifetime of an individual
why is not every trait as plastic as possible
- its costly, and not always feasible evolutionarily
- organisms can misinterpret cues and have maladaptive plastic responses
Trait-mediated interactions
indirect effect of species A on species C, mediated through the consequences of expressing a trait that is in response to species B
evolution
changes in the relative frequencies of heritable traits within a population
- can be in terms of phenotypic changes (morphology, behavior, physiology, life history) and the behavior of alleles/genotypes within a population
Hardy-Weinburg Equilibrium
evolution is a change in the frequencies of alleles in the gene pool of a population
(p+q)2 = 1
p= frequency of allele 1 for trait A
q= frequency of allele 2 for trait A
Why do populations deviate from Hardy-Weinburg
- mutation
- genetic drift
- gene flow
- natural selection
- artificial selection
genetic drift
change of allelic frequencies between generations just by chance. “Random walk” of small deviations add up over generations
- Inversely related to N
-Large N: drift causes very small differences
- Small N: major changes in genetic composition in a population. Random events have a disproportionally large effect on gene frequencies
bottleneck effect
a reduction of genetic diversity in a population due to a large reduction in population size (ex: from loss of food)
founder effect
when a small number of individuals leave a large population to colonize a new area and bring with them only a small amount of genetic variation
directional selection
when individuals with extreme phenotypes experience higher fitness than the average population phenotypes
stabilizing selection
when individuals with intermediate phenotypes have higher survival and reproductive success than those with extreme phenotypes
disruptive selection
when individuals with wither extreme phenotype experience higher fitness than individuals with an intermediate phenotype
- by removing the intermediate phenotype, genetic and phenotypic variation increases
Misconceptions about natural selection
- Selection and evolution are NOT the same thing
- POPULATIONS CHANGE DURING EVOLUTION NOT individuals
- selection can result in evolution after 1 generation
microevolution
time period, whats evolving, whats studied, what changes
- short time period
- conspecific populations are evolving
- changes in allele frequencies and gene interactions are studied
- this changes properties of populations
macroevolution
- long time period
- species as a whole is evolving into new species
- probabilities of speciation and extinction are studied
- this alters relative frequencies of species with different properties
premating reproductive barriers
- habitat isolation
- temporal isolation
- immigrant inviability
- sexual preferences
postmating reproductive barriers
- genetic incompatibility
- low hybrid fitness
- low hybrid sexiness
allopatric speciation
the evolution of a new species through the process of geographic isolation
parapatric speciation
the evolution of new species when populations are contiguous (no specific extrinsic barrier to gene flow, just non-random mating)
clines
geographic gradients tin the frequencies of genotypes or phenotypes of the same species
- can be caused by a geographic gradient in selection (ex: temp, predation)
biogeographic rules
when clines point to the same pattern over many species (interspecific)
Toward the poles…
- body size inc
- extremities are shorter
- less pigmentation
adaptive radiation
rapid diversification of a lineage into several new ones because of appearance of available niche space
niche
a species unique set of conditions (biotic and abiotic) that it needs and can tolerate
key innovation
a trait or set of traits that allows an organism to exploit a novel resource
intrinsic
relys on key innovation
extrinsically
open niche space (archipelago), remove large predators/herbivores
life histories
organisms patterns of growth, development, and reproduction
- optimize survival and res=production in the face of ecological challenges to maximize fitness
tradeoffs in life history traits
exist because energy available to an organism is limited
semelparity
breed once and die
iteroparity
reproduce multiple times in a lifetime
life tables
demographic tool, helps to visualize different life history strategies
down-side to early reproduction
- growth vs. reproduction tradeoff results in smaller final size
- smaller size may result in lower survival, no later reproduction
phenology
the timing of recurring biological phenomena
behavior
one of the three groups of trait that make up a a phenotype
vegetative reproduction
- form of asexual reproduction
- from somatic cells
parthenogenesis
- form of asexual reproduction
- from reproductive cells
- embryo is produced without fertilization
clones
individuals from rhe same parent that bear the same genotype
asexual reproduction
- 100% of genes are copied
- energy input goes totally toward producing offspring
- removing mutations is impossible (clonal) or unlikely (with recombination)–> sex removes mutations (mutations accumulate in asexual species over time; long term evolutionary persistence of asexual species is LOW)
sexual reproduction
- 50% of genes are copied
- energy input: finding a mate, competing for a mate, dealing with disease, injury, or death risk, time expended, producing offspring
- removing mutations: likely
hermaphrodite
- can mate with yourself
- can minimize costs of finding mates/competition, because you can produce whatever gametes are in short supply in population (avoid competition)
- many plants, mollusks, worms
protogyny
female-> male
protandry
male-> female
frequency-dependent selection
when natural selection favors the rarer phenotype in a population
- will result in parents trying to manipulate the sex of their offspring
- the environment may determine whether sons or daughters have greater fitness
Trivers Willard hypothesis
because reproductive success of sons tends to be more variable and resource-sensitive than that of daughters, parental investment into high-quality sons yields greater reproductive returns than comparable investment into high-quality daughters
satellite/sneaker males
small, inferior males hang around large, dominant males in hopes of gaining (sneaking) the opportunity to fertilize eggs
female mimicry
some small, inferior males mimic females; dominant males don’t chase them away and the get access to females
isogamy
gametes are the same size
anisogamy
gametes of different sizes
implications of anisogamy for females
- females invest more into each gamete
- females need to make sure each of her limited number of offspring survive to maximize her fitness
implications of anisogamy for males
- invest less into each gamete
- needs to fertilize as many eggs as possible to increase his fitness
Bateman’s principle
females have more “time out” than males and there are fewer females available at any given time
mating system
the number of mates each individual has and the permanence of the relationship with those mates
promiscuity
males mate with multiple females and females mate with multiple males and do not create lasting social bonds; common among animals and outcrossing plants
Polygyny
a polygamous mating system in which a male mates with more than one female
- resource defense polygyny (male can defend females/a territory a female is using)
polygyny
lek
a polygamous mating system in which a male mates with more than one female
- lek= bit of space where males congregate, females wander around lek and choose a male
Polyandry
a polygamous mating system in which a female mates with more than one male
- done in areas where ther eis high predation
monogamy
when a social bond between a male and female persists through the period that is required for them to rear offspring
extra-pair copulations
when an individual that has a social bond with a mate also breeds with other individuals
- may se this strategy to obtain superior genotypes and produce offspring with better genetics
mate guarding
- a behavior in which one partner prevents the other partner from participating in extra pair copulations
- physical restraint/accompaniment
- chasing/luring other potential mates away
- preventing females (or males) from mating again
copulatory plug
semen hardens in vaginal canal so other competitors can’t fertilize eggs
detatchable palps
breaks off reproductive appendage in females opening-> prevents others from mating, male can defend female better
sexually selected traits
any trait that enhances success in competition for mates
primary sexual characteristics
traits related to differences between the sexes in terms of body size, ornaments, color, and courtship
sexual dimorphism
the difference in the phenotype between males and females of the same species (ex; body size, courtship behaviors… etc)
direct (material benefits)
nuptial, spermatophore, suicide, paretn theory, harssment, good health
- nuptial gifts (females will select mates that provide the biggest gift of food)
- edible spermatophores (part sperm/food/baby food)
- sexual suicide (male himself is the resource; happens when male is unlikely to mate again)
- good parent theory (display traits that correlate with quality of parental care)
- male sexual harassment is costly–> desirable males may be the ones that reduce these costs for females
- good health hypothesis (mating with a healthy mate witll reduce chances of infection or yourself or offspring–> bright feathers are hard to maintin if sick)
indirect benefits
courtship, good genes, sexy sons
- courtship and ornamentation serve as primary funtion of signalling an individuals quality
- good genes hypothesis–> Zahavi’s handicap principle (individuals can afford to self-handicap must have prettu good genes to survive this handicap)
- sexy sons hypothesis (females like male trait-> preferentially mate with males with trait-> sons inherit trait, daughters inherit preference for trait-> genes spread in population-> runaway selection)
social behaviors
interactions with members of one’s own species, including mates, offspring, and unrelated individuals
predator avoidance
group may be able to fend off predators better than an individual
dilution effect
reduced probability of predation to a single animal when in a group
predator avoidance vs competition for food
larger groups are better able to locate food, but food must be shared among all members
foraging/feeding efficiency
many individuals searching for food may be able to find rare food more easily
- probability of prey capture may inc in a group
- social predators often hunt social prey
maximizing benefits of group living
- must minimize costs
- natural selection will favor the evolution of group size that maximizes benefits and minimizes costs
- sociality is plastic for many species
allee effect
inverse relationship between population density and growth rate- accelerate the decline of species in peril
donor
individual who directs a behavior toward another individual as part of a social interaction
recipient
the individual who receives the behavior of a donor in a social interaction
cooperation
when donor and recipient of a social behavior both experience increased fitness from an interaction
selfishness
when the donor of a social behavior experiences increased fitness and the recipient experiences decreased fitness
spitefulness
when a social interaction reduces the fitness of both donor and recipient (does not occur in natural populations
altruism
a social interaction that increases recipient fitness and decreases fitness of the donor
reciprocal altruism
appears altruistic in short run, but is cooperative in long run
- needs to be 1) benefit to recipient exceeds cost to donor, some mechanism must protect against “cheaters”
- rare in nature
coercion and policing
coercion/punishment and policing enforces altruism in the recipient
kin selection
when altruism does not lead to direct fitness (the fitness an individual gains by passing on copies of its genes to its offspring)
coefficient of relatedness
the numerical probability of an individual and its relatives carrying copies of the same genes from a recent common ancestor
indirect fitness benefit
equation
Indirect fitness benefit = B x r
B= benefit given to recipient relative
r= coefficient of relatedness between donor and recipient
B x r > C(costs)
coordinating action
tight feedback between particular individuals that have different roles during hunting
curtailing cheating and selfishness
1) spatial based discrimination
2) armpit effect
3) greebeard effect
armpit effect
if an animal develops a standard for comparison by learning its own phenotypes
greenbeard effect
if an animal recognizes which other individuals carry the same “altruism” gene because of an identifying label (ex: “green beard”)
