BSC 108 Final (Exam 3)

Microevolution

The change in a population's gene pool over a succession of generations (the allele frequency changes to help the species to adapt to the environment)

Macroevolution

The evolutionary change above the species level. This includes the origin of a new group through speciation events, impact of mass extinction on the diversity of life and origin of key adaptations

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

Allopatric Speciation

The formation of a new species in populations that are geographically isolated from one another; evolve independently after the barrier

Sympatric Speciation

The formation of a new species in populations that live in the same geographic area; can be associated with a genetic barrier due to a single mutational event

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

Segregation of habitat
Major alterations in mate recognition/behavior
Genetic incompatibility

What are the two models of the Pace of Speciation?

Gradualism and Punctured Equilibrium

What is Gradualism?

It is the first model for the Pace of Speciation. This is the slow and steady accumulation of small changes leads to production of species over vast stretched of time. Fossils should show numerous forms in a continuous series of change (though they don't)

Who presented the idea of Gradualism?

Charles Darwin

What is Punctured Equilibrium?

This is the second model of the Pace of Speciation. This says species diverge in spurts of rapid change followed by long periods of stasis (nothing). These fossils should show drastic changes at the time that a new species branches from the parent

Who presented the idea of Punctured Equilibrium?

Eldredge and Gould

Prezygotic Barriers

These are barriers that prevent mating between species or hinders fertilization of eggs if members of different species attempt to mate

What are the Prezygotic Barriers?

Temporal Isolation
Habitat Isolation
Behavioral Isolation
Mechanical Isolation
Gametic Isolation

Temporal Isolation

Mating or fertilization that occurs at different seasons/times of the day

Habitat Isolation

When they live in different habitats so they do not meet, even if the same geological area

Behavioral Isolation

When there is little to no sexual attraction due to different, complex courtship displays

Mechanical Isolation

When there are structural differences that prevent the organisms from mating

Gametic Isolation

When the egg and sperm fail to unite and fuse together to produce an offspring

Postzygotic Barriers

These are barriers that prevent the development of fertile adults if hybridization occurs via failure to survive or failure to reproduce

What are the Postzygotic Barriers?

Reduced Hybrid Viability
Reduced Hybrid Fertility
Hybrid Breakdown

Reduced Hybrid Viability

This is when hybrid zygotes fail to develop or fail to reach sexual maturity

Reduced Hybrid Fertility

This is when hybrids fail to produce functional gametes (sterile)

Hybrid Breakdown

This is when hybrids are feeble/weak or sterile

Ecology

The scientific study of the interactions between organisms and their environments

Abiotic Factors

These are the nonliving components of an ecosystem that shape its environment

What are the Abiotic Factors?

Air in the form of wind (carries seeds)
Water (balance, drying out)
Light (as an energy source)
Minerals in the form of rocks and soil
Temperature (metabolism)

Biotic Factors

These are the living components of a biological community; any organism that is part of an individual's environment

What are the Biotic Factors?

Examples include: fish, humans, dogs, insects, plants, birds, coral reefs

What are the 4 levels of ecology?

Organismal Ecology
Population Ecology
Community Ecology
Ecosystem Ecology

Organismal Ecology

Evolutionary adaptations of organisms to meet challenges of abiotic factors

Population Ecology

Groups of individuals of the same species in the same are

Community Ecology

Groups of populations of different species

Ecosystem Ecology

Include all abiotic factors plus community of species in the area

Habitat

A place where an organism lives; the specific environment/geographical location

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

Physiological Responses
Anatomical Responses
Behavioral Responses

Physiological Responses

Includes temperature regulation and ability to be at equilibrium

Anatomical Responses

Includes the change in body shape and structure (thick fur in winter, body position/size)

Behavioral Responses

Includes the change in action such as moving to a new location

Name two types of Aquatic Biomes and the salinity of each

Freshwater Biome (less than 1%)
Marine Biome (3%)

What are some uses for freshwater?

Drinking water
Crop irrigation
Sanitation & Industry

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

Freshwater includes standing water and flowing water
Standing = lakes, ponds
Flowing = rivers, streams

Wetlands

An ecosystem intermediate between an aquatic ecosystem and a terrestrial ecosystem, soil is saturated with water permanently or periodically

Estuaries

An area where a freshwater stream or river merges with seawater

How are Terrestrial Biomes determined? Know examples

They are determined by climate, especially temperature and rainfall
Examples include: tropical forest, savanna, desert, chaparral, temperate grassland, temperate broadleaf forest, coniferous forest, arctic tundra, high mountains and polar ice

Tree Line

The altitude where no plants or animals live because of the environmental conditions; roughly at 12,000 feet above sea level

Know the Water Cycle

Sea: water evaporates from the sea; forms clouds of water vapor and precipitates into the sea
Land: water evaporates from lake/stream and from plants (called transpiration), forms clouds of water vapor and precipitates onto the land
Connecting: clouds over the sea can be pushed to land by wind; water sinks into soil and flows from there back to the sea

Population Density

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

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

It involved the trapping animals, marking them with tags and then recapturing them after a period of time
It is utilized to estimate population density of a species in a particular area

What are the 2 growth models?

Exponential Growth
Logistic Growth

Exponential Growth & Graph

Expansion of population in an ideal, unlimited environment
Graph looks like a J

Logistic Growth & Graph

Population growth that decreases as population size approaches carrying capacity
Graph looks like an S shape

Carrying Capacity

The maximum population size that a particular environment can sustain (with no net increase or decrease)

How does the U.S. Engaged Species Act define an endangered species versus a threatened species?

Endangered Species: those in dangers of extinction throughout all or a significant portion of its range
Threatened Species: likely to become endangered in the foreseeable/near future

Community

An assemblage of populations of different species inhabiting and potentially interacting in a particular area

Ecological Niche

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

What did G.F. Gause study? What organism did he use?

He studied the effects of interspecific competition in two closely related protists: Paramecium Aurelia and Paramecium Caudatum

What were G.F. Gauses results?

He found that species with identical niches will lead to the extinction of one of the species until they evolve to use a different set of resources (this is the foundation of the competitive exclusion principle)

Competitive Exclusion Principle

The concept that populations of two species cannot coexist in a community if their niches are nearly identical. Using resources more efficiently and having a reproductive advantage, one of the species will eventually out compete and eliminate the other

Predator vs. Prey

Predator: an animal who kills and eats other animals
Prey: animal who is hunted and eaten

What are some plant defenses against herbivores?

Thorns, spines, and chemical toxins (morphine, nicotine, peppermint)

What are some of the animal defenses against predators?

Passive defense (hiding)
Active defense (escaping)
Mechanical defense (hard shell)
Behavioral defense (mobbing)
Distraction displays
Camoflage
Warning colorations
Mimicry
Herbivory

Why do organisms enter into Symbiotic Relationships?

They enter into these relationships with those who have a close physical association with one another. As a result, both gain something from interacting (Nemo and the sea anemone)

What types of Symbiotic Relationships exist?

Mutualism: +/+
Predation: +/-
Herbivory: +/-
Parasite & Pathogen: +/-
Commensalism: +/0

Trophic Level

The feeding relationships among the various species in a community

Know the different Trophic Levels and examples of organisms at each

Producers: plants, grass
Primary Consumers: insects, small bunny (herbivore)
Secondary Consumers: frogs, mice armadillo (eat bugs)
Tertiary Consumers: snake, eagle (eat small animals)

What are the 4 main nutrients that cycle?

Carbon, Nitrogen, Phosphorus and Oxygen

Biological Magnification

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

Energy Pyramid

A diagram depicting the cumulative loss of energy with each transfer to the subsequent trophic level in a food chain (lot - to less - to almost no energy)

Why are introduced species bad?

Introduced species can become invasive species which grow and take over the area from plants currently living there. They colonize and kill other species, reducing biodiversity of the area

How are humans impacting ecosystems?

Humans are by far the largest species who require the most resources. As a result, we are taking resources from others, space and impacting their way of life as a result of our living conditions. This causes species to adapt or they will become extinct

Why is biodiversity important?

Humans rely on biodiversity for food, clothing, shelter, oxygen, soil fertility and medicinal substances.
Losing biodiversity limits potential for new discoveries of food, medicine. This can also be seen to have large-scale changes on environment, leading to catastrophic damage

Food web

A diagram of the feeding relationships in an ecosystem (interconnecting food chains)

What factors increase the loss of biodiversity?

Habitat destruction
Invasive Species
Overexploitation

Sustainable Development

The development that meets the needs of people today without limits the ability of future generations to meet their needs

Species Richness

The total number of different species in a community

Relative Abundance

The proportional representation of a species in a biological community (how many per species)

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

On November 24th, 1859 Darwin published "On the Origin of Species by Means of Natural Selection"

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

Point One: organisms inhabiting Earth today descended from ancestral species
Point Two: natural selection was the mechanism for descent with modification

Natural Selection

The process in which individuals with certain inherited traits are more likely to survive and reproduce than are individuals that do not have those traits

What is the result of natural selection?

The result is evolutionary adaptation

What were the key observations which Darwin based his theory of natural selection?

Observation I: geographic distribution of organisms on the Galapagos Islands
Observation II: the fact that Galapagos organisms resembled those in South America

Unequal Reproductive Success

When individuals with traits best suited for their environment leave their most fertile offspring

Homologous Structures

Features that often have different functions but are structurally similar because of common ancestry.
Examples include the human limb to the bat wing to the whale fin to the cat arm

Biogeography

The study of the past and present distribution of organisms

Comparative Anatomy

The comparison of body structures between different species

Comparative Embryology

The comparison of different structures that differ during the development of different organisms

Fossil

A preserved imprint or remain of an organism that lived in the past

How are fossils formed?

They are created by river beds

Where are fossils found?

They are found in rock layers, allowing scientists to determine their age

What type of scientist studies fossils?

Paleontologist

Name 3 examples of natural selection in action

Pesticide resistance in insects/bugs
Development of bacteria to become antibiotic resistant
Drug resistant strains of HIV

Mutation

Any change to the genetic information of a cell or virus

Sexual recombination

The process of shuffling alleles during meiosis to create genetic variation in what is expressed

Directional Selection

The natural selection that acts in favor of the individuals at one end of a phenotypic range
This shifts the graph to the right

Disruptive Selection

The natural selection that favors extreme over intermediate phenotypes
This has maximums before and after the original graph

Stabilizing Selection

The natural selection that favors intermediate variants by acting against extreme phenotypes
This makes the graph taller at the current phenotype

Sickle-cell anemia confers resistance to what disease?

Malaria

Population

A group of interacting individuals belonging to one species and living in the same geographic area at the same time

Community

All the organisms inhabiting and potentially interacting in a particular area; groups of many different species

Ecosystem

All of the organisms in a given area, along with the nonliving (abiotic) factors with which they interact; community plus physical environment