BIOL211 Exam 4

What is speciation?

the process by which one species splits into two or more species

Describe the Biological Species Concept.

States that a species is a group of populations whose members have the potential to interbreed in nature and produce viable, fertile offspring

What are the limitations to the Biological Species Concept?

doesn’t work for organisms that reproduce asexually (bacteria) or fossils

Describe the Morphological Species Concept.

distinguishes a species by body shape and other structural features

Define the ecological species concept.

defines a species in terms of its ecological niche

Define the phylogenetic species concept.

distinguishes groups that share a common ancestor determined by molecular sequence and morphological observations

What is the current view of speciation?

strong biological species concepts with addition of phylogenetic concepts

What is allopatric speciation?

when gene flow is interrupted when a population is divided into geographically isolated subpopulations

Describe the Bahama Blue Holes.

allopatric separation where differences in body shape were dependent on different predation levels

How do islands contribute to separation?

colonized remote areas isolates a species and limits gene flow between different species

How do geographic barriers lead to speciation?

different mutations arise, genetic drift, different selection in different environments

What is sympatric speciation?

speciation within populations that live in the same geographic area

What causes sympatric speciation?

polyploidy, sexual selection, and habitat differentiation

What is polyploidy?

changes to the gene during cell division that leads to formation of different species

What are prezygotic barriers?

barriers to reproduction that occur before a zygote forms

What is habitat isolation

environment keeps species separate

What is behavioral isolation?

specialized mating unique to certain species for mate recognition

What is temporal isolation?

differences in timing of when they reproduce/breed

What is mechanical isolation?

morphological differences prevent mating

What is gametic isolation?

sperm of one species unable to fertilize the eff of another species

What are postzygotic barriers?

reproductive barriers that prevents a hybrid zygote from developing into a viable, fertile adult

What is reduced hybrid viability?

hybrid offspring has a short lifespan

What is reduced hybrid fertility?

hybrid offspring unable to reproduce

What is hybrid breakdown?

hybrid offspring can survive and reproduce, but cannot produce viable or fertile offspring

What is ecology?

the scientific study of the interactions between organisms and the environment

Describe Tropical Forests.

areas with high temperatures and precipitation, high diversity, and stratified plant canopies that lead to intense sunlight competition

What are epiphytes?

plants that grow on plants

What are lianas?

vines

Describe Deserts.

areas with low precipitation and variable temperatures, scattered plants that are adapted to low precipitation

How do animals adapt in deserts?

structures that limit water loss and high nocturnal activity

What are savanas?

areas with warm temperatures and high rainfall in wet seasons and dry seasons, scattered trees in a grassland, periodic fires, large herbivores

What are chapparrals?

areas with seasonal precipitation and temperatures (mild wet winters and hot dry summers), and fire prone shrubs and small trees

What are temperate grasslands?

areas with variated temperatures and high seasonal precipitations, frequent fires

How are plants adapted to temperate grasslands?

below ground, adapt to fires, droughts, grazing, and are able to go dormant

What are temperate broadleaf forests?

areas with high precipitation, seasonal temperatures, distinctive seasons and canopy stratas

What are coniferous forests (taiga)?

areas with heavy snow, low precipitation and temperatures

How are plants adapted to taigas?

trees have narrow crowns to shed snow and reduced leaves (needles)

What are tundras?

areas with extremely cold temperatures, low precipitation, with distinctive permafrost

How does temperature and light influence biome type?

input of solar energy warms the atmosphere, land, and water to establish temperature variations, movements of air and water, and evaporation of water (determination of seasons)

How does temperature and precipitation influence biome type?

movement of water influence temperature distributions

What is a population?

group of individuals of a single species living in the same area and interacting with each other

What is density?

the number of individuals per unit area or volume

What is the goal of population ecology?

understanding the factors that influence the size of populations

Describe the results of the seed experiment.

high density of seeds reduced germination likely from signal cues to inhibit germination

What is dispersion?

the pattern of spacing among individuals within a population

What is clumped dispersion?

concentrated areas of individuals of a population

What is uniform dispersion?

evenly divided spaces

What is random dispersion?

uneven arrangement

Which dispersion pattern provided the most plant growth?

clumped

What influences population size?

forces that add or subtract individuals

What processes influence population size?

birth, death, immigration, emigration

How are population sizes measured?

sample/census, mark-recapture

What is mark-recapture?

estimates population size by capturing, marking, and releasing individuals

What is demography?

the study of characteristics that influence population density and dispersion patterns

What is a life table?

summarizes survival and reproductive rates of individuals in a specific age group; follows lifespan of a cohort until death

Describe the life table of ground squirrels.

lots of offspring from 2-6 years of age

What is a survivorship curve?

plot of number of those alive in a certain age group

What is a type 1 survivorship curve?

flat at the start then a steep drop

What causes a type 1 curve?

few offspring are produced, but they are provided good care throughout their lifespan

What are examples of type 1 curves?

large mammals such as elephants or humans

What is a type 2 curve?

constant rate of death

What are examples of a type 2 curve?

ground squirrels

What is a type 3 curve?

sharp drop at start then flattens out

What causes a type 3 curve?

large numbers of offspring that get little to no care over time

What are examples of a type 3 curve?

fish, oyster

How are reproductive rates used in demography?

identifies how reproductive output varies with the number of breeding females and their ages

What are single reproductive episodes?

an organism invests all its energy into a single massive reproductive event before dying

What are multiple reproductive episodes?

produce offspring multiple time throughout their lives which spreads reproductive risk over time

What factors limit the number of offspring?

finite resources to allocate for reproduction and tradeoff between number of offspring and resources to prepare

What are reproductive tradeoffs that are dependent on environmental conditions?

predictability of rainfall and food, likelihood of right soil and light conditions, risk of predation

What is exponential population growth?

population that increases in size by a constant proportion

What is the intrinsic rate of increase?

the rate at which an exponentially growing population increases in size at each instant in time

What is carrying capacity?

the maximum population size that a particular environment can sustain

What is logistic population growth?

the addition of carrying capacity to exponential growth model

What kind of curve does exponential growth yield?

J-shaped

What kind of curve does logistic growth yield?

S-shaped

What factors regulate populations?

competition, pathogens, predators

What is a metapopulation?

when a number of local populations are linked together

What is a fixed action pattern?

a sequence of unlearned acts directly linked to a simple stimulus

Describe fixed action patterns in sticklebacks.

aggressive swimming when near red objects

Describe fixed action patterns in bats.

detect water by using the echo sounds that bounce off water

What is kinesis?

random movement in response to changes in conditions

What is taxis?

oriented movement towards a particular stimuli

What is migration?

a regular, long-distance change in location

How do animals find their way during migration?

circadian rhythms relative to the position of the sun, position of North Star, magnetic poles, and chemical signaling between individuals

How does circadian rhythm work?

uses a transcription translation feedback loop in which the time it takes for a metabolism corresponds to the time

How do honeybees use visual communication?

set of movements and vibrations that indicates the direction and distance of a flowering plant

What are pheromones?

chemical cues that act in air or water

How do moths use pheromones?

females release to attract males for reproduction

How do minnows use pheromones?

released by dead individuals to signal the presence of a predator

What is imprinting?

the establishment of a long-lasting behavioral response to a particular individual or object during a sensitive period

What is spatial learning?

the establishment of a memory that reflects the environment’s spatial structure

How did digger wasps display spatial learning?

learned that their nest is located in the center of a circle of pinecones; when only the pinecones were moved, they still looked for the nest in the center of the pinecones

What is associative learning?

the ability to associate one environmental feature with a past experience

What is modeling?

learned through observations

What is the optimal foraging theory?

states that natural selection should favor a foraging behavior that minimizes the cost of foraging and maximizes its benefits

What drop height is preferred by crows?

5.23 m

What is species richness?

the number of different species in a community

What is species diversity?

the variety of different kinds of organisms that make up a community

What is species abundance?

the number of individuals within a certain species