BIOL214 exam 1 study

ecology

the study of interactions among organisms and between organisms and their environments

organismal ecology

investigates how individuals’ adaptations and choices affect their reproduction and survival (includes evolutionary, behavioral, and physiological ecology) 

population ecology

focuses on populations, groups of interbreeding individuals that occur in the same place at the same time

community ecology 

focuses on factors that influence the number of species in an area 

ecosystems ecology

describes the passage of energy and nutrients through communities

Nov. 24, 1859

Darwin published “on the Origin of species by means of natural selection”

observations

overproduction, limited resources, variation, & heritability

conclusions

competition, natural selection, & evolution

evolution

the change in heritable characteristics of biological populations over generations

homology

characteristics shared among related individuals because of common ancestry

synapamorphy

a derived characteristic shared among a common ancestor and its descendants 

2nd law of thermodynamics

in every energy transformation, free energy is reduced because heat energy is lost from the ecosystem in the process

Cetacea

order for whales, dolphins, and porpoises

Uniformitarianism

the idea that the natural law observable around us now are also responsible for events in the past

isotopes

forms of elements with different numbers of neutrons

biomarkers

distinctive molecules only produced through biological activity (molecular fossils)

directional selection

favors one extreme phenotype

stabilizing selection

favors intermediate phenotypes; extremes selected against 

balancing selection 

maintains diversity via heterozygote advantage or frequency dependent selection

disruptive selection

favors both extremes; intermediates selected against

biological species concept

reproductive isolation defines species

phylogenetic species concept

diagnosable, distinct group based on unique characteristics

evolutionary species concept

lineage with unique tendencies and fate

ecological species concept

species defined by a unique ecological niche

pre-zygotic barrier

prevents mating or fertilization (habitat, temporal, behavioral, mechanical isolation) 

post-zygotic barrier

hybrids are inviable, sterile, or have reduced fitness

allopatric speciation

geographic barrier separates populations —> reproductive isolation

sympatric speciation

divergence without physical barriers, often through ecological niches, polyploidy, or disruptive selection

red queen hypothesis

species must constantly evolve to survive in changing environments; extinction = failure to keep pace 

Hadley cell

causes warm, moist air to rise at the equator, creating rainfall; descending air at 30º latitude creates dry deserts

lagerstatten

sites that contain usually well-preserved fossils, including soft tissues

ferrel cell

extends from the equator to 30ºN

polar cell

extends from 30ºN and above

upwelling

when surface currents move water away from coasts, brining nutrient-rich deep water to the surface 

Langmuir Circulation 

circulation pattern affecing nutrient distribution and productivity 

Thermohaline circulation

global circulation driven by temperature and salinity differences

oligotrophic lakes

nutrient poor, clear water, low productivity, high oxygen often deeper

eutrophic lakes

nutrient rich, murky water, high productivity, oxygen depletion possible in deep layer, often shallow

swamps

tree dominated

marshes

herbaceous, nutrient rich wetlands (no trees)

bogs

acidic, nutrient-poor wetlands dominated by mosses

fens

groundwater-fed, more nutrients than bogs 

isochron

a line on a graph of isotope ratios that indicates mineral samples formed at a similar time 

syzygy tide

alignment of the moon, sun, and earth which causes spring tides (higher than average tides) 

neap tide

occurs when the moon, sun, and earth are at 90º (lower than average tides)

viral reassortment

occurs when genetic material from different strain is mixed into new combinations within a single cell

Dobzhansky’s essay

evolutionary theory converts biology as a collection of facts into a system of knowledge 

phylogeny 

a visual representation of the evolutionary history of a lineage 

viral particles

consist of a type of nucleic acid enclosed in a protein coat

evolution of H7N9, virus jumped from

wild birds to ducks to chickens

genetic drift

evolution arising from random changes in the genetic composition of a population from one generation to the next

taxon

a cohesive group of species

taxonomy

the process of classifying species

Lamarckian thinking

if an animal lost its limb, the offspring of that animal would lack the same limb

evolutionary change occurs in nature through 

natural selection, sexual selection, and genetic drift 

oldest fossil discovered 

bacteria

Lord Kelvin’s estimate of the age of Earth did not account for 

earth being a rigid sphere 

zircons

have occasionally survived for billions of years and can contain chemical signatures that have yielded clues about early earth 

recent uptick in biodiversity

the successful advent of multicellularity and division of labor

chordates

share a notochord, pharyngeal slits, and lungs

recent adaptations

dinosaur extinction enabled mammals to take advantage of resources and habitats once controlled by the reptiles

pseudoextinction

when a species can disappear when a lineage is transformed over evolutionary time or divides into two or more separate lineages

neritic zone

the zone that extends from intertidal zone to the edge of the continental shelf 

epilimnion 

an upper layer in temperate lakes that is warmed by the sun and mixed well by the wind