Module 6

Evolution

Evolution

change in genetic makeup and features of population over time

Ideas of Buffon

new species change from original ancestor over time to thrive in new locations

Hutton's (and Lyell's) Uniformitarianism

Earth shaped by gradual geographic changes over long periods of time

Cuvier's Catastrophism

earth shaped by violent catastrophes that only current species survived

Lamarck's Inheritance of Acquired Characteristics

individual acquire traits through use or disuse; successful traits are then passed onto offspring

Darwin's (and Wallace's) Natural Selection

individuals are born with different traits- those with successful traits survive and pass traits to offspring.

Do organisms acquire successful traits intentionally?

They are acquired from random mutations, not intentionally.

Is an organism's trait successful in any environment?

Successful traits are suited to certain environments and can be unsuccessful if conditions change.

Compare Inheritance of Acquired Characteristics and Natural Selection

Inheritance of acquired characteristics (Lamarck)- parent acquires trait so it can survive and reproduce

Natural Selection (Darwin (and Wallace))- parent born with successful trait- survives and reproduces

Artificial Selection

choosing and breeding offspring for desirable traits

5 ways to study evolution

-fossils

-embryology

-molecules and genetics

-comparative anatomy

-biogeography

Fossils

slight structural differences between early species and current ones show changes in traits over time

Comparative Anatomy

similar body parts across different species can indicate a common ancestor

Homologous Structures

similar internal structures, different functions; indicates a common ancestor

Vestigial Structures

small, non dysfunctional body structures

Analogous Structures

different internal structures, similar functions; no common ancestor

Embryology

comparing development between species can identify a common ancestor

Biogeography

location of current species can show where separation from common ancestor and adaptation to new area occurred.

Molecules and Genetics

slight differences in protein and DNA can trace ancestry between species

Species

population independently of other populations

Speciation

formation of new species after two populations are isolated and then diverge

Allopatric Speciation

populations are isolated geographically

Sympatric Speciation

populations are isolated, even in some locations

Prezygotic isolation barriers

prevent reproduction and fertilization

Postzygotic isolation barriers

prevent viable, fertile offspring

Hybrid

offspring of parents of different species- often sterile

Extinction

death of all members of a species- evolution naturally turns over species

gene pool, determine # of alleles if given population

total alleles of gene in population (population x 2)

allele frequency, determine # if given # of alleles and population

% of an allele out of the total in gene pool (# of A or a/ gene pool)

5 requirements to meet Hardy-Weinberg principle

-no mutations

-no migration in/out (no gene flow)

-population big enough to avoid genetic drift

-random mating

-no natural selection

5 ways to fail to meet Hardy-Weinberg principle

-Mutations

-Migration of individuals

-Genetic drift due to small population

-Nonrandom mating

-Natural selection

Mutation

change in organism's genetic material- introduces new alleles population (increase diversity)

Gene Flow

movement of alleles between populations

Genetic Drift

allele frequency change due to chance- plays off of inheriting a trait

Bottleneck Effect

population drastically reduced in short period of time- losing many alleles - permanent loss of diversity

Founder Effect

small group leaves home to form own isolated population

Nonrandom Mating

select mates to reproduce based on preference

Sexual Selection (Identify above based on how it changes population, example)

natural selection that attracts mate to reproduce successfully

Which gender often has the elaborate adaptation? Which gender chooses the partner?

Males often have elaborate adaptations to compete for females. Females select for good genes or help with offspring.

Directional Selection (Identify above based on how it changes population, bell curve, example)

one extreme trait favored, the environment selects against the others, moves population in one direction

Diversifying (Disruptive) Selection (Identify above based on how it changes population, bell curve, example)

both extreme traits are favored over an intermediate trait, which may divide the population into 2 species over time

Stabilizing Selection (Identify above based on how it changes population, bell curve, example)

intermediate trait is favored over extremes,in stable environments, decreases variety in population

Exponential Growth

accelerating increase in population size, more births than deaths; J Curve

Boom and Bust Cycle

rapid growth followed by sudden decline in population size

Logistic Growth

rapid growth, then population stabilizes at carrying capacity; S shaped curve

Carrying Capacity

highest population that does not damage ecosystem

Competition

organisms attempt to use same, limited resources, both harmed

Predation

organism eats another organism- one harmed

Parasitism

organism lives in or on another organism. harming it, symbiotic relationship

Commensalism

organism lives in or on another organism, not harming it, symbiotic relationship

Mutualism

organism lives in or on another, both benefit, symbiotic relationship

Primary Succession

colonization of newly formed land (rock and lava) by organisms

Secondary Succession

colonization of disturbed community by organisms

Producers

make own food

Decomposers

eat detritus (organism remnants such as waste, dead tissues)

Consumers

eat other organisms

Tertiary Consumers

eat secondary consumers

Secondary Consumers

eat primary consumers

Primary Consumers

eat producers

Carnivores

eat consumers

Herbivores

eat producers

Detrivores

eat producers and consumers detritus

Describe 10% law in relation to the Food Pyramid

10% of energy from food source is available to consumer, rest is used or lost as heat

Hydrologic Cycle Reservoirs and processes

reservoirs- atmosphere, oceans, freshwater, groundwater\

processes- evaporation, precipitation, seepage, runoff, streamflow

Carbon cycle reservoirs and processes

Reservoirs: atmosphere, oceans, soil, fossil fuels

Processes: fire, respiration, photosynthesis, uptake by consumers, decomposition, runoff

Nitrogen cycle reservoirs and processes

Reservoirs: atmosphere, oceans, freshwater, soil

Processes: lightning, denitrification, nitrogen-fixation, uptake by producers and consumers, decomposition, runoff

Phosphorus cycle reservoirs and processes

Reservoirs: rock, soil, oceans, freshwater

Processes: runoff, uptake by producers, decomposition, rock formation

Biome

ecosystem characterized by plant community

Tropical Rain Forest

Location: Central and South America, Africa, Southeast Asia

Vegetation: broadleaf evergreen trees(broadleaf: tree with leaves that have broad blades; evergreen: leaves are dropped and regrown year-round rather than losing all leaves at once in a seasonal pattern)

Conditions: 68-93o F year-round, 50-200 inches rain/year; rainy and dry seasons; warm and moist

Other: 1/2of Earth's species live here, with fierce competition for sunlight among plants

Savanna

Location: Africa, South America, Australia

Vegetation: a few scattered trees; mostly grassland forbs(flowering plants)

Conditions: 75-84o F,4-20 inches rain/year; 8-9 months of the hot dry season

Other: most of Earth's large mammal species live here

Desert

Location: every continent

Vegetation: ranges from no plants to specialized plants adapted to conditions

Conditions: 12 inches or less rain/year; dry; lack of atmospheric water causes sharp temperature decreases at night

Chaparral

Location: North America(southwest), Europe and Africa around the Mediterranean Sea, Australia

Vegetation: a few trees; shrubs adapted to growth and replenishment from periodic fires in area

Conditions: 26-30 inches rain/year in warm winters; dry summers

Grassland (Praire)

Location: North America(midwest), Europe, Asia

Vegetation: dense grasses, with very few trees

Conditions: 10-30 inches rain/year; true summer and winter seasons(freezing can occur)

Temperate Deciduous Forest

Location: North America(eastern), Europe(western), Asia(eastern), New Zealand

Vegetation: mostly broadleaf deciduous trees(deciduous: all leaves are dropped in winter seasons due to less sunlight and frozen groundwater supply, then regrown in spring seasons when photosynthesis conditions improve)

Conditions: 30-60 inches rain/year; true summer and winter seasons(freezing can occur)

Coniferous forest (boreal forest)

Location: North America(northern), Europe(northern), Asia(northern)

Vegetation: mostly evergreen conifer trees(conifer: tree with pine needles for leaves and cones for reproduction)

Conditions: 16-40 inches rain or snow/year(mostly snow); long, cold winter seasons

Other: largest biome

Tundra

Location: North America(northern), Europe(northern), Asia(northern)

Vegetation: flowers, small plants, no trees due to permafrost in deeper soil

Conditions: 10 inches or less rain or snow/year(mostly snow); very long winter seasons at -30oF or less

Other: shortest growing season(10-12 weeks)

Biodiversity

variety of living species on biosphere

Mass Extinction

sudden loss of many species in relatively short time

5 threats to biological diversity

-habitat destruction

-overharvesting

-pollution

-invasive species

-climate change

4 characteristics of sustainable ecosystem

-diverse communities

-stable populations at carrying capacity

-efficient use and reuse of raw materials

-renewable sources of energy