APES Units 1-4

APES flashcards for units 1-4 (not collegeboard's units)

Evolution

A change in the genetic composition of a population over time

Microevolution

Evolution below the species level

Macroevolution

When genetic changes give rise to new species/genera/families/classes/phyla

Speciation

Macroevolution that is only evolution of species

Genes

Physical locations of chromosomes within each cell of an organism

Alleles

Different forms of DNA

Genotype

Complete set of genes in an individual

Phenotype

Actual set of traits expressed in an individual

Mutation

Occasional mistake in DNA copying process produces a random change in genetic code

Most mutations are _________

Detrimental

Recombination

When chromosomes are being duplicated and a piece of a chromosome breaks off and attaches to another chromosome

Evolution by artificial selection

Humans determine which individuals to breed

Unintended results of artificial selection

Herbicide resistance, antibiotic/antibacterial/drug resistance

Evolution by natural selection

Environment determines survival + reproduction

Alfred Wallace

Put unifying theory of evolution together along with Darwin

Charles Darwin

Put pieces of unifying theory of evolution together along with Wallace; naturalist on HMS Beagle

On the Origin of Species by Means of Natural Selection

Described Darwin’s theory of evolution

Fitness

An organism’s ability to survive + reproduce

Adaptations

Traits that improve fitness

Gene flow

Process by which individuals move between populations and alter genetic compositions

Genetic drift

Change in genetic composition of a population over time as a result of random mating - more impactful in small populations

Bottleneck effect

Drastic reduction in population size that reduces genetic variation

Bottleneck effect issues

Diseases, less adaptability, low fertility, can cause extinction

Extinction

When the last remaining individual in a species dies out

Founder effect

A change in genetic composition because a population descends from a small number of colonizing individuals

Range of tolerance

Limits to the abiotic conditions (temperature, humidity, salinity, pH) of a species

Fundamental niche

The suite of abiotic conditions under which a species can survive, grow, and reproduce

Realized nice

Range of abiotic + biotic conditions under which a species actually lives

Species distribution

Where the species actually lives

Niche generalists

Species that can live under a wide range of conditions

Niche specialists

Species that live under a narrow range of conditions

Fossilized organisms

Organisms are hardened into rocklike material when buried under layers of sediment

Global mass extinctions

When large numbers of species went extinct over relatively short time periods (5)

Largest global mass extinction

251 mya, 90% of marine species and 70% of land vertebrates went extinct

Global mass extinction (most recent)

End of Cretaceous period (65 mya) - ½ of species (including dinosaurs) went extinct b/c a meteorite caused a dust cloud that stopped photosynthesis

Sixth Mass Extinction

Current - human caused

Community ecology

Study of interactions among species

Symbiotic relationships

2 species live in close association with one another

Competition

Struggle of individuals to obtain a shared limiting resource (mutually harmful)

Competitive exclusion principle

2 species competing for the same limiting resource can’t coexist

Resource partitioning

2 species divide a resource based on differences in behavior/morphology

Temporal resource partitioning

Same resource, different times

Spatial resource partitioning

Same resource, different habitats

Morphological resource partitioning

Evolution of different body sizes/shapes

Predation

1 animal kills and consumes other animal

Parasitoids

Animals that lay eggs inside other organisms - when eggs hatch, parasitoid larvae kill host by consuming it from the inside out

Parasitism

1 organism lives on/in a host [other organism]

Pathogens

Parasites that cause disease

Herbivory

When an animal consumes a producer

Mutualism

2 species benefit each other

Commensalisms

Interactions in which 1 species benefits and 1 is neither helped or hurt

Keystone species

Not abundant but have large effects - more significant role than abundance suggests

Ecosystem engineer

Species that creates/maintains habitat

Ecological succession

The predictable replacement of one group of species by another group of species over time

Primary succession

Succession that begins w/ bare rock + no soil

Secondary succession

In areas that have been disturbed but haven’t lost their soil

Pioneer species

Can colonize new areas rapidly and grow well in full sunshine

Climax community

(historical) final stage of succession, but no longer recognized

Theory of island biogeography

Habitat size and distance from the mainland are important in determining species richness

A majority of livestock species come from:

Donkeys, buffalo, cattle, goats, horses, pigs, sheep, chickens, ducks, geese, and turkeys

Effects of low genetic diversity

Harder to survive environmental change, prone to inbreeding depression

Effects of high genetic diversity

Wider range of genotypes, improved chances of survival

Data-deficient species

No reliable data

Extinct species

Existed as recently as 1500 but don’t today

Threatened species

High risk of extinction

Near-threatened species

Likely to become threatened

Least-concern species

Widespread and abundant

Intrinsic value

Value independent of human benefit

Instrumental value

Value because it is an instrument or tool to accomplish a goal

Provisions

Goods produced by ecosystems that humans can use directly

Native species

Species that live in their historical range

Exotic/alien species

Live outside their historical range

Invasive species

Exotic species that spread rapidly and cause harm

Kudzu vine

Native to Japan and Southeast China, introduced in the US in 1876 to reduce erosion

Zebra mussel

Native to the Black Sea and the Caspian Sea, cargo ships pumped out ballast water with the mussels

Silver carp

Native to Asia, outcompete native species in the Great Lakes

Overharvesting

Individuals are removed faster than they are replaced

Convention on International Trade in Endangered Species of Wild Fauna and Flora

UN regulations (183 countries) from 1973

Primary productivity

The rate at which solar energy is converted into organic compounds via photosynthesis (kcal/m²/yr)

Gross Primary Productivity (GPP)

The total rate of photosynthesis in a given area - amount of energy plant takes in + glucose made (kcal/m²/yr)

Net Primary Productivity (NPP)

Rate of energy stored by photosynthesizers in a given area, after subtracting the energy lost to respiration (kcal/m²/yr)

The 2nd Law of Thermodynamics

Energy transfers from one organism/thing to another

Trophic levels

The different levels of the food chain

Photosynthesis equation

Sun energy + CO_2 + H_2O → C_6H_{12}O_6 + O_2

Chemosynthesis

Energy created from chemicals

Respiration equation

Reverse of photosynthesis - produces ATP

Producers

Autotrophs - make their own food

Consumers

Heterotrophs - obtain food by eating others

List of trophic levels

Producers → Primary consumers/herbivores → Primary/tertiary consumers/carnivores

Omnivores

Eat both plants/animals

Scavengers

Not predators, feed on dead organisms - opportunistic

Detritivores

Feed on dead or dying organisms - cast offs (like leaves)

Decomposers

Break organic dust into nutrients to enter cycles

Food chain

Depicts the flow of energy from one organism to the next

Food web

Shows an interlocking pattern of food chains

Positive feedback loops

1 incident → another → another → … → another

Negative feedback loop

1st thing → 2nd thing → … → 1st thing → 2nd thing → …

Trophic cascade

When one part of the food chain is altered, it affects the other organisms higher/lower on the chain

Species diversity

number of different species

Species richness

The number of different species in an ecosystem