ecoevo exam1 key terms

weather

conditions of the atmosphere during a short period of time (mins to mons)

climate

long-term, predictable atmospheric conditions present in a specific area (years, decades, or longer)

haze-effect cooling

effect of the gases and solids from a volcanic eruption on global climate

milankovitch cycles

cyclic changes in the earth’s orbit that may affect climate (long time scale - tens to thousands of years)

solar intensity

amount of solar power energy the sun emits

greenhouse effect

warming of earth due to carbon dioxide and other greenhouse gases in the atmosphere - trapping of infrared radiation heat from the emitted from earth’s surface

keeling curve

co2 concentrations at Mauna Loa observatory consistently rise each year

C12

carbon isotope preferentially taken up by plants during photosynthesis (it’s lighter)

coal

compressed peat

oil and natural gas

remains of small plant/animal matter compressed by the sea

hydrocarbons

formed from the remains of dead plants or animals

main driver of climate change

increase in human population, increase in per-capita fossil fuel use, and the resulting greenhouse gases and therefore greenhouse effect

predictions of climate change

warmer temps, increased frequency extreme events, increased ocean acidification, increased rates of extinction

positive feedback

changes due to climate change result in accelerated warming. ex: melting ice caps → more absorption of solar radiation → increased warming → melting ice caps etc.

polar jet stream

strong wind separating cold polar air from relatively warmer temperate air

phenology

study of the timing of periodic life cycle events. ex: flowering time, bird migration.

distribution shifts with climate

ex: insects that prefer cooler temperatures will migrate north as the earth near the equator warms. insects in the old region will die, and there will be fewer insects deep into the new region

declining habitat size

climatically suitable region for an animal gets much smaller, the population size decreases. ex: polar region decreases due to melting ice caps, polar bears cannot move much farther north

migration barrier

a geographic barrier (natural or man made like a city) lies in the way of a species migrating away from climate change

limited dispersal ability

climatically suitable region for a species shifts, the the entire population is also not able to shift (ex: butterflies are just not able to fly that far or fast)

critical unknowns

unknown reasons why a species is not able to fully migrate to the climatically suitable region (ex: other species already inhabits the region, behavior or adaptation, etc)

reducing greenhouse gas emissions

category of mitigation: reducing fossil fuel use, increasing energy efficiency, lifestyle changes

conserving natural carbon sinks

category of mitigation: less deforestation, especially in tropical forests or wetlands

carbon capture and storage

category of mitigation: CO2 extracted from the atmosphere and put into long term storage

evolution

change in allele frequencies of a population across generations

causes of evolution

natural selection

genetic drift

migration

mutation

19c and earlier

time period: species are fixed; species are independent; the earth is young

law of superposition

steno: layers of rock are arranged in a time sequence (young layers near the top)

Steno

first to recognize fossils were remains of organisms

fossils

the preserved remains (body __) or traces (trace __) of organisms from prehistoric time

permineralization

minerals enter dead organic material and forms an internal cast

path to preservation

permineralization, trapped in amber, or frozen

hutton and lyell

who had the idea: geologists that studied rock types and layers; slow but continuous process of erosion and uplift; the earth is old; fossils were confined to distinct layers

cuvier

who: first recognition of extinction; fossils resemble but are not exactly the same as modern species

homology

species share common themes in their anatomy. Includes morphology, embryology, and molecular

homologous structures

parallel (similar) structures in diverse organisms that were inherited from a common ancestor

morphology

homology: the study of the animals, plants, etc and the relationship between their parts. ex: bones in forelimbs of vertebrates

embryology

homology: study of embryonic development. ex: tail in developing embryos of vertebrates

molecular

homology: evolution concerned with genes. ex: similarity in genes of fruit flies in mammals

vestigial structure

physical structure present in an organism but has no or little apparent function and appears to be from a functional structure in a distant ancestor. ex: appendix, tailbone

law of succession

extinct species were succeeded by similar species

transitional feature

trait in a fossil that is intermediate between ancestral (older) and derived (newer) species

lamarck

who: continuous use of an organ results in its growth and disuse causes shrinkage, these trait changes are passed to offspring

inheritance of acquired traits

incorrect theory by lamarck. trait changes can be passed to offspring

malthus

who: if left unchecked, organisms produce more offspring than can survive

malthusian catastrophe

without regulation, human population size will become too large and lead to war/famine/disease. There will then be a population crash back to subsistence levels

17-18c

time period: species change through time, life on earth is ancient, transitional fossils document changes in traits of related species, homologous traits are common, closely related species live in the same area

darwin and wallace

who: natural selection and fitness

modern synthesis

overarching evolutionary paradigm that took shape in the 1940s that is generally accepted today: combined darwin and wallace with mendel

natural selection

reproduction of individuals with favorable genetic traits that survive environmental change because of those traits, leading to evolutionary change

peter and rosemary grant

who: example of natural selection. small seeds become scarce, big beaked birds survive and reproduce. after intense rainfall, big seeds become scarce and opposite occurs

polygenic trait

trait controlled by multiple genes

4 postulates of natural selection

variation among individuals

some of that variation is heritable

survival and reproductive success is variable

individuals best able to survive and reproduce is not a random sample

adaptation

heritable trait or behavior in an organism that aids in its survival and reproduction in its present environment

note: environments change, and these kinds of traits also change

heredity

the transmission of genetic characteristics from parents to offspring

heritability

the fraction of population variation that can be attributed to its genetic variance

mendel

who: each parent passes a combination of discrete alleles, dominant and recessive

evolutionary fitness

individual’s ability to survive and reproduce

relative fitness

individual’s ability to survive and reproduce relative to the rest of the population

selection pressure

environmental factor that causes one phenotype to be better than another (abiotic or biotic)

hoekstra

who: studied genetic basis of adaptation through the morphology and behavior in mice (rock pocket mice)

stabilizing selection

selection that favors average phenotypes

mean stays the same and genetic variation is reduced

directional selection

selection that favors phenotypes at one end of the spectrum of existing variation

mean moves in direction with higher fitness and genetic variation is reduced

diversifying selection

selection that favors 2 or more distinct phenotypes

mean could stay the same (depends on relative peaks) and genetic variation is increased

positive frequency-dependent selection

selection that favors phenotypes that are common - stabilizing selection

negative frequency-dependent selection

selection that favors phenotypes that are rare - diversifying selection when considered over multiple generations (ex: lefty/righty fish)

sexual dimophism

phenotypic differences between males and females (males are typically more decorated, larger, stronger)

sexual selection

selection that favors phenotypes that increase ability to obtain or choose good mates

fundamental asymmetry of sex

females generally invest more time in offspring. female fitness is limited to eggs/parental care, male fitness is limited to access to mates

honest signal

trait that gives truthful impression of an individual’s fitness

handicap principle

traits are costly handicaps such that only the fittest individuals can afford the cost (ex: peacock tail). Only high quality mates can produce this handicap and still survive

good genes hypothesis

individuals develop impressive ornaments to show off their efficient metabolism and/or ability to fight disease (ex: bright colors are produced in fish with good diets, displaying their good genes result in high quality diet)

genetic drift

change in allele frequencies in a population across generations due to random events (punnet square results are random)

affects the whole genome and is random with respect to fitness

bottleneck effect

magnification of genetic drift as a result of natural events or catastrophes

founder effect

event that initiates an allele frequency change in part of the population, which is not typical of the original population (portion of population leaves)

migration/gene flow

flow of alleles in and out of a population due to the individual movement of individuals or gametes

makes populations more genetically similar

can increase, decrease, or have no effect on fitness or genetic diversity

mutation

changes to DNA; ultimate source of new alleles

increases genetic diversity and is generally random

deleterious

since most organisms are well adapted to their environment, mutations in coding/regulatory regions most often lower fitness

pleiotropy

single gene affects multiple traits; results in genetic correlation

ecology

study of the distribution and abundance of organisms, the interaction between organisms, and the interaction between organisms and their environment

organism

individual

population

group of potentially interbreeding organisms that are members of the same species (conspecific) living in the same area at the same time

community

populations of different species (heterospecific) within an area and the interactions among them

ecosystem

all the biotic and abiotic components of an area

biosphere

all the ecosystems of earth

biogeography

the study pf the geographic distribution of living things and the abiotic factors that affect their distribution

endemic

species found only in a specific geographic area that is usually restricted in size

niche

range of resources that a species can use and the range of conditions that it can tolerate

biomes

ecological community of plants, animals, and other organisms that is adapted to a characteristic set of environmental conditions

net primary productivity

measurement of the energy accumulation within an ecosystem

carbon fixed (biomass generated) - carbon released (cellular respiration)

whittaker

who: biome concept separated into zones that form 3 triangles, tropical temperate and boreal-polar. also forms 2 zones based on precipitation: forest and no forest

tropical wet forests

warm/hot and stable, lack of seasons

high precipitation

broad leafed evergreen plants

high biodiversity

high npp

savanna tropical grassland

warm/hot and stable

low precipitation, extensive dry season

grasses

tropical regions with low rainfall

subtropical deserts

warm/hot with some variation over a year and large temp change between day and night

very low precipitation

plants adapted to low water availability

typically between 15-30º N/S of equator

east

moisture-laden air blows from the west onshore. in what direction is the rain shadow?

chaparral

warm

low precipitation, mostly winter

shrubs adapted to periodic fires

coastal southern ca and mediterranean

temperate grasslands

seasonal warm/cool

low and seasonal precipitation

grasses

mid latitudes

soils often deep and rich in organic matter, but cold winter temps and frozen water creates defined growing season

temperate forests

seasonal, warm/cool

low/moderate precipitation

deciduous trees

mid latitudes

soils often rich in organic matter due to leaf litter, but cold winter temps and frozen water create defined growing season

earths tilt

why do we have seasons?

boreal forests/tiaga

seasonal, cool/cold

low precipitation, but enough to support a forest

cold-tolerant conifers

soils have lower nutrient availability that temperate biomes because needles drop less frequently and decompose slower

little water evaporation due to cold temps