BSC 108 final exam

What is micro-evolution?

Changes in allele frequencies within populations, often associated with adaptation, can be measured from one generation to the next, “small changes”

What is macro-evolution?

Major changes in the history of life, origin of new species, generates biological diversity, “big changes”

What is a species?

a group of populations whose members have the potential to interbreed with one another in nature to produce fertile offspring

What is allopatric speciation?

Species evolve in geographic isolation, usually associated with a geographic barrier that prevents members of 2 populations from mating with each other, involves independent evolution of the populations after the barrier arises. "Physical separation"

What is sympatric specation?

Species evolve without geographic isolation,probably associated with a genetic barrier due to a single mutational event, important in plants. "Genetic separation"

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

Segregation of habitat, major alterations in mate recognition or behavior, genetic incompatibility

The two models of the Pace of Speciation

Gradualism-slow and steady accumulation of small changes leads to production of species over vast stretches of time

Punctuated equilibrium-species diverge in spurts of rapid change, followed by long periods of stasis

What are prezygotic barriers? Know the 5 types

Prevent mating or fertilization between species. 5 types are: temporal isolation, habitat isolation, behavioral isolation, mechanical isolation, and gametic isolation

Example of temporal isolation

Eastern and Western spotted skunks mate at different times of year, preventing them from producing offspring even in areas where the two species live together

Example of habitat isolation

Even though they occupy the same geographic area, these two species of garter snakes occupy different habitats, preventing them from mating

Example of behavioral isolation

Blue footed boobies and many other animals use complex courtship displays in selecting mates. Because other species cannot mimic these displays, offspring are not produced with members of other species

Example of mechanical isolation

Snails of different species in the genus Bradybaena may attempt to mate, but differences in the shapes of their shells prevent them from succeeding

Example of gametic isolation

Although the sperm and eggs of these two sea urchin species are released into the water, they are unable to fuse because the proteins on the surface of the eggs and sperm cannot bind to one another

What are postzygotic barriers? Know the 3 types

Prevent survival or reproduction of hybrid offspring. 3 types are hybrid inviability (miscarriage), hybrid sterility (sterile offspring), and hybrid breakdown(1st generation produces sterile/weak 2nd generation)

Example of hybrid inviability

Different salamander species sometimes mate, but the offspring fail to complete development, keeping the gene pools of the two species isolated from one another

Example of hybrid sterility

Different species may mate, and produce viable offspring that are sterile, preventing further mixing of gene pools. Mules are robust animals, offspring of a donkey and horse, but they cannot reproduce

Example of hybrid breakdown (a post-zygotic barrier)

The first generation of hybrids may be both viable and fertile, but due to genetic factors the offspring of these hybrids are weak, feeble, or sterile, as in domesticated rice strains.

The 8 classification levels for naming a species

Domain, kingdom, phylum, class, order, family, genus, species

The 8 classification levels for human beings

Domain: Eukaryota, Kingdom: Animilia, Phylum: Chordata, Class: Mammalia, Order: Primates, Family: Hominidae, Genus: Homo, Species: sapiens

EACMPHHS

What is ecology?

the scientific study of the interactions between organisms and their environments

What are abiotic factors? Know the 5 examples

The nonliving chemical and physical factors in an environment. 5 examples are water, sunlight, oxygen, temperature, and soil.

What are biotic factors? Know some examples

The living factors in an environment

What are the four levels of ecology? Know what each is concerned with

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

Population ecology-concerned with populations and the factors that affect population density and growth

Community ecology-concerned with communities and how interactions between species affect community structure and organization

Ecosystem ecology-concerned with ecosystems and the energy flow and cycling of chemicals among the various abiotic and biotic 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

Name 2 types of aquatic biomes. What is the salinity of each?

Freshwater biomes- salt concentration

What are some uses for freshwater?

drinking water, crop irrigation, sanitation and industry

What are the 2 categories of freshwater? Know examples of each

Standing water- lakes and ponds

Flowing water - rivers and streams

What are wetlands?

transitional biome between an aquatic ecosystem and a terrestrial one

What are estuaries?

areas where a freshwater stream or river merge with the ocean

How are terrestrial biomes determined? Know the examples from class

Distribution depends largely on climate, are named for major physical or climatic features and for their predominant vegetation. Examples include tropical forest, savanna, desert, chaparral, temperate grassland, temperate broadleaf forest, coniferous forest, arctic tundra, polar ice

Alabama is in temperate broadleaf forest

What is the tree line?

the edge of the habitat at which trees are capable of growing. Beyond the tree line, trees cannot tolerate the environmental conditions (usually cold temperatures or lack of moisture)

What is the water cycle?

Evaporation and transpiration, condensation, precipitation, collection. See chart pg 39 Ch. 18

What is population density?

the number of individuals of species per unit of area or volume

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

Animals are trapped, marked, and then recaptured after a period of time, utilized because an estimate of the total population size can be obtained without counting every single individual

What is the age structure of a population? Why is it utilized?

the proportion of individuals in different age groups, utilized because age structure of a population can help us understand the history of a populations survival or reproductive success and how it relates to environmental factors and its a useful tool for predicting future changes in a population

What are the 2 growth models? Know what each one looks like on a graph

Exponential growth model (upward curve) and logistic growth model (downward curve, then plateaus)

What is carrying capacity?

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

How does the US Endangered Species act define an "endangered species" vs a "threatened species"?

endangered species is in danger of extinction throughout all or a significant portion of its range, threatened species is likely to become endangered in the foreseeable future

What is a community?

assemblages of species living close enough for potential interaction

What is an ecological niche?

the sum total of a species' use of the biotic and abiotic resources in its environment

What did G.F. Gause study? What model organism did he use? What were his results?

Studied the effects of interspecific competition in two closely related species of protists. He used the paramecium as his model organism. His results were that 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 so similar that they compete for the same limiting resources cannot coexist in the same place. two outcomes: extinction of one species, or one species evolves to use different resources

What's the difference between predator and prey?

Predator kills and eats another species, prey is killed and eaten by another species. Predators have adaptations such as claws, teeth, fangs, stingers or poison to help catch and subdue prey, are fast/agile, and most have acute senses

What are some of the plant defenses against herbivores?

spines/thorns, chemical toxins (morphine,strychnine, nicotine)

What are some of the animal defenses aganist predators?

Passive defenses (hiding), active defenses (escaping), mechanical defenses (hard shells or quills), behavioral defenses (alarm calls/mobbing), distraction displays (direct attention of the predator away from a vulnerable prey to another prey that is more likely to escape), camouflage/ cryptic coloration (a passive defense that makes a potential prey difficult to spot against its background), chemical (brightly colored/ "warning coloration"), mimicry (one species mimics the appearance of another)

Why do organisms enter into symbiotic relationships?

one or both of the organisms receives benefits from the relationship that could not be obtained otherwise

What types of symbiotic relationships are there?

Mutualism-both organisms benefit from the relationship

Commensalism-one organism benefits, and the other is not affected in any manner

Parasitism-one organism benefits, and the other is harmed

What is a trophic level?

the position of an organism in the food chain, a food chain is the sequence of food transfer between trophic levels

What are the different trophic levels? Know examples of organisms that belong in each

Producers-> primary consumers-> secondary consumers-> tertiary consumers-> quarternary consumers

Producers: flower,phytoplankton

Primary consumers: herbivores,zooplankton

Secondary consumers: mice,fish

Tertiary consumers: snakes, sharks

Quarternary consumers: hawks, whales

What are the 4 main nutrients that cycle? Know where they cycle through

Carbon, water, nitrogen, oxygen. Cycle throughout ecosystems, and through living matter

What is biological magnification?

a process in which toxins become more concentrated in successive trophic levels of a food web

What is an energy pyramid?

much of the energy that flows as organic matter through the trophic levels of an ecosystem is lost at each link

How are humans impacting ecosystems?

decreasing biodiversity, destroying communities, pollution, over hunting/fishing, introducing invasive species, and also sustainability

Why is biodiversity important?

humans rely on biodiversity for food, clothing, shelter, oxygen, soil fertility and medicinal substances.

Why does energy flow, but nutrients cycle?

Energy is lost at each link of the food chain, so it cannot be recycled like nutrients are

What is a food web? Be able to read one

a diagram representing the feeding relationships in a community

What factors increase the loss of biodiversity?

invasive species, habitat destruction, overexplotation, community ecology

What is sustainable development?

development that balances current human well-being and economic advancement with resource management for the benefit of future generations

What is species richness? What is relative abundance?

Both are components of the diversity of a community

Species richness is the total number of different species in a community

Relative abundance is how common or rare a species is relative to other species in a community

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" published in 1859

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

Organisms inhabiting Earth today descended from ancestral species

Natural selection was the mechanism for descent with modification

What is the basic idea of natural selection?

organisms can change over generations 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- all species produce excessive numbers, which leads to struggle for existence

Individual variation- variation exists among individuals in a population and much of this variation is heritable

What is unequal reproductive success? \*test question\*

AKA natural selection

Those individuals with traits best suited for the local environment leave more fertile offspring

What are homologous structures? Know the examples we talked about.

the similarity in structures due to common ancestry

Ex: cat, human, whale and bat all have 2 similar bones in their arm

What is biogeography?

the study of the geographic distribution of species

What is comparative anatomy?

comparison of body structure between different species, confirms that evolution is a remodeling process

What is comparative embryology?

comparison of structures that appear during the development of different organisms

Comparative embryology of vertebrates support evolutionary theory

What is a fossil? How are fossils formed?

preserved remnants or impressions left by organisms that lived in the past, often found in sedimentary rocks

formed by rivers bringing sediment to the ocean, sedimentary rocks containing fossils form on the ocean floor, over time additional stata are added containing fossils from each time period, the sea levels change and the rocks are exposed

Where are fossils found?

in sedimentary rocks on the ocean floor, technically everywhere

What type of scientist studies fossils?

paleontologists

Name 3 examples of natural selection in action.

pesticide resistance in insects, development of antibiotic-resistant bacteria, drug resistant strains of HIV

What is a mutation?

changes in the DNA of an organism

What is sexual recombination?

shuffles alleles during meiosis

What is directional selection? What does the phenotypic graph look like compared to the original population curve?

shifts the phenotypic curve of a population, selects in favor of some extreme phenotype

What is disruptive selection? What does the phenotypic graph look like compared to the original population curve?

splits the phenotypic curve of a population (m shape vs. the original n shape)

can lead to a balance between two or more contrasting morphs in a population

What is stabilizing selection? What does the phenotypic graph look like compared to the original population curve?

stretches the phenotypic curve of a population to be taller and thinner

maintains variations for a particular trait within a narrow range

Sickle-cell anemia confers resistance to what disease?

Malaria

Define population, community, ecosystem, and biosphere

Population- number of members of a species in a particular area

community- sum of the populations inhabiting a particular area

ecosystem- all of the Biotic and abiotic factors in an area

biosphere- the global ecosystem; the entire portion of the earth is inhabited by life

What is a geographic range?

the area or distribution of a species in a geographic area that species can be found

Define biotic potential

the maximum reproductive capacity of a population under optimum environmental conditions

What is an exponential growth curve? What shape is this curve?

rate of population increase under ideal conditions

"J" shaped

What is the rule of 72?

If you take the average % population growth of a population and divide that into the number 72, you will get the number of years it will take for that population to double

Define carrying capacity.

the maximum population size of the species that the environment can sustain indefinitely, given the food, habitat, water and other necessities available in the environment

What are some factors that limit biotic potential?

Environmental resistance: unfavorable climate conditions, lack of space, light, or a suitable substrate; deficiencies of necessary chemical compounds or minerals, and the inhibiting effects of predators, parasites, disease organisms, or unfavorable genetic changes

Name 5 factors that have increased the biotic potential for humans.

antibiotics (preventing the spread of deadly disease), building "upwards" (which increases the space available to live), agriculture (growing our own food allows us to produce more food than we would if we were still hunters/gatherers), becoming the top predator due to the creation of tools

Define growth rate.

the change in the size of a poluation over a period of time

What is the current human growth rate?

75 million people / year

Define niche.

the status of an organism within its environment and community (affecting its survival as a species)

What are producers and consumers?

Producers- organisms that can make their own energy/ food through biochemical processes

Consumers- an organism that obtains food by feeding on other organisms or producers because it cannot produce its own food

Which way does energy flow through ecosystems?

From producer-> consumers

Up

What is a biological pyramid? (same as an energy pyramid)

a diagram that illustrates the cumulative loss of energy with each transfer in a food chain

How much energy is available to the next level in a biological pyramid?

90% of the energy is lost at each trophic level and 10% is passed on

How much sunlight energy is captured by producers?

What is eutrophication?

an overabundance of nutrients in a body of water, usually as a result of runoff from the surrounding land

What are some things we can do to move toward a sustainable future?

turn off lights, reuse and recycle, use more energy-efficient lightbulbs, carpool or walk, buy local, eat more veggies

According to the principle of interspecific competition, two species cannot continue to occupy the same \_____.

ecological niche

What type of population interaction benefits neither population?

competition