bio 108 exam 4

Evolution

change over time

Natural selection

mechanism for the change

What is microevolution?

Changes in allele frequencies within populations; can be measured from one generation to the next

What is macroevolution?

Major changes in the history of life; generates biological diversity

What is a species?

A population or group of populations whose members have the potential to interbreed with one another in nature to produce fertile offspring reproductively isolated from other such groups

What is allopatric speciation?

Species evolve in geographic isolation; involves evolution of the populations after the barrier arises; chances increase if the population is small

What is sympatric speciation?

Species evolve without geographic isolation, they remain together; important to plants but not widespread among animals; requires a subdivision of the gene pools of single population

What special circumstances are required to keep the gene pools separated in sympatric speciation?

Subdivisions of the gene pool; segregation of habitat, major alterations in mate recognition of behavior, and genetic incompatibility

Polyploidy

 the condition of having extra sets of chromosomes

Know the two models of the Pace of Speciation.

Gradualism and punctuated equilibrium

Gradualism

darwin; slow and steady accumulation of small changes leads to production of species over vast stretches of time; leads to numerous forms in a continuous series of change in fossil records

Punctuated equilibrium

eldredge and gould; species diverge in spurts of rapid change, followed by long periods of stasis; leads to drastic changes in fossil records

What are prezygotic barriers? Know the 5 types.

Prevent mating or fertilization between species; temporal, habitat, behavioral, mechanical, and genetic isolation

What are postzygotic barriers? Know the 3 types.

Prevent survival or reproduction of hybrid offspring; hybrid inviability, sterility, and breakdown

Evo devo

the scientific interface between evolutionary biology and the study of embryonic development

Exaptation

many complex structures evolve in one context and are later modified by natural selection for other functions

Plate tectonics

continents constantly moving; arrangement affects species distribution and climate

Permian extinction

pangea; 90% of marine life gone; land dwelling organisms also affected

Cretaceous extinction

end of cretaceous; dinosaurs extinguished; led to rise of mammals

Cretaceous extinction

recycle nutrients from dead organic material; fallen leaves, feces, and other organisms

Plant symbiosis

help roots absorb water and nutrients

Humans

The scientific study of the interactions between organisms and their environments

What is ecology?

The scientific study of the interactions between organisms and their environments

What are abiotic factors?

The nonliving chemical and physical factors in an environment

What are biotic factors?

The living factors in an environment

What are the four levels of ecology?

Organismal, population, community, and ecosystem

Organismal

concerned with evolutionary adaptations that enable individual organisms to meet the challenges posed by their abiotic environments

Population

concentrates mainly on factors that affect population density and growth

Community

focuses on how interaction between species affect community structure and organization

Ecosystem

focuses on energy flow and the cycling of chemicals among the various abiotic and biotic factors

Biosphere

the global ecosystem

Global distribution patterns

reflect regional differences in climate and other abiotic factors

What is a habitat?

Specific environments in which organisms live

What are 3 types of adaptations that enable organisms to adjust to changes in their environment?

Physiological, anatomical, and behavioral

Acclimation

a physiological response that is long term

The ability to acclimate

related to the range of environmental conditions a species naturally experiences

Population ecology

the study of how members of a population interact with their environments

Biomes

a major terrestrial or aquatic life zone characterized by vegetation type in terrestrial biomes or the physical environment in aquatic biomes

Name 2 types of Aquatic Biomes?

Freshwater and marine biomes

Freshwater biomes

lakes, streams, rivers,and wetlands; salt concentration less than 1%

Marine biomes

oceans, intertidal zones, coral reefs, and estuaries; sal concentration of about 3%

What are some uses for freshwater?

Used for drinking water, crop irrigation, sanitation and industry

What are the 2 categories of freshwater?

Standing water and flowing water

Standing water

Flowing water

Flowing water

rivers and streams

Lakes and ponds

have communities of plants, algae and animals

Rivers and streams

support different communities rather than lakes and ponds

What are wetlands?

Transitional biome between and aquatic ecosystem and a terrestrial one

What are estuaries?

Areas where a freshwater stream or river merges with the ocean; one of the most biological productive environments on earth

How are terrestrial biomes determined? Know the examples from class.

Primarily by climate, especially temperature and rainfall; heated by the direct rays of the sun, air at the equator rises, then cools, forms clouds, and drops rain

What is the tree line?

The edge of the habitat, at high elevation or latitudes, beyond which trees cannot grow due to harsh conditions like extreme cold, wind, or low moisture

The water cycle.

The continuous movement of water on, above, and below earth’s surface, driven by solar energy and gravity

Sustainability

the goal of developing, managing and conserving earth resources to meet the needs of people today without compromising

What is population density?

The number of individuals of a species per unit of area or volume

How do we measure population density

 estimated by indirect indicators such as number of bird nests or rodent burrows

Population density

the age structure of a population is the proportion of individuals in different age groups

What is the mark-and-recapture technique and why is it utilized?

A scientific method that is used to estimate the size of animal populations that are too mobile or large to count individually

What are the 2 growth models?

Exponential and logistic growth

Exponential growth

describes the rate of expansion of a population under ideal, unregulated conditions; j shaped

Logistic growth

describes growth of an idealized population that is slowed by limiting factors

Growth rate

the change in population size per time interval

What is carrying capacity?

The number of individuals in a population that the environment can just maintain with no net increase or decrease

How does the US Endangered Species Act define an endangered species?

An animal that is in danger of extinction throughout all or a significant portion of its range

How does the US Endangered Species Act define a threatened species?

An animal likely to become endangered in the foreseeable future

Human population growth

based on the same parameters that affect other populations like birth and death rates

What is a community?

Assemblages of species living close enough for potential interactions.

What is an ecological niche?

The sum total of a species’ use of the biotic and abiotic resources in its environment; Species ecological role.

What did G. F. Gause study?

The effects of interspecific competition in two closely related species of protists.

What model organism did G. F. Gause utilize?

Protozoan ciliates of the genus Paramecium

What were G. F. Gause results?

Two species so similar that they compete for the same limiting resources cannot coexist in the same place

What does the competitive exclusion principle state?

Two species cannot coexist in a community if their niches are identical.

Predator

kills and eats

Prey

is killed and eaten

What are some of the plant defenses against herbivores?

Spines, thorns, and chemical toxins such as morphine, strychnine, nicotine, cinnamon, peppermint etc.

What are some of the animal defenses against predators?

Hiding, escaping, mechanical or chemical defenses, behavioral (alarming, mobbing), distraction, camouflage, coloration, mimicry

Why do organisms enter into symbiotic relationships?

Enhance their chances of survival and reproduction by gaining access to food, shelter, protection, or nutrients

What types of symbiotic relationships are there?

Mutualism, Commensalism, and Parasitism

Mutualism

both benefit

Commensalism

one benefits, one neutral

Parasitism

one benefits, one harmed

What is a trophic level?

Specific position an organism occupies in a food chain.

Producers

produce their own food. plants

Primary consumers

animals that eat producers, mice, grasshoppers, deer

Secondary consumers

carnivores or omnivores that eat primary, like frogs, snakes, spiders, fish

Tertiary consumers

carnivores that eat secondary consumers, hawks, snakes, coyotes

What are the 4 main nutrients that cycle?

Water, carbon, nitrogen, phosphorus.

What is an energy pyramid?

Graphical model showing the flow of energy through an ecosystem’s trophic levels. Shows energy decreases as it moves up.

Why are introduced species bad?

Environmental impact, economic costs, life history traits, ecosystem disruption

How are humans impacting ecosystems?

Deforestation, Pollution, Climate Change, Land Use Changes

Why is biodiversity important?

Humans rely on biodiversity for food, clothing, shelter, oxygen, soil fertility, medical substance

What is a food web?

The feeding relationships in an ecosystem.

What factors increase the loss of biodiversity?

Habitat destruction, Invasive species (kudzu), Overexploitation

What is sustainable development?

Balances human needs with the health of the biosphere

What is species richness?

The total number of different species in  the community

What is relative abundance?

The proportional representation of a species in a biological community; one component of species diversity

What was the name of the publication that Darwin published? In what year was it published?

On the Origin of Species by Means of Natural Selection. 1859.

What are the two main points of Darwin’s publication?

Organisms inhabiting Earth today descended from ancestral species and Individuals with certain heritable traits leave more offspring than others

What is the result of natural selection?

Evolutionary adaptation

Darwin based his theory of natural selection on two key observations. What are the two observations?

Overproduction and Individual variation

Overproduction

All species tend to produce excessive numbers and Leads to a struggle for existence