What was the name of the publication that Darwin published?
On the Origin of Species by Means of Natural Selection
What is the name of Darwin's ship?
The Beagle
What is the name of the Islands where Darwin conducted most of his research?
The Gal�pagos Islands
What are the two main points of Darwin's publication?
a.Organisms inhabiting Earth today descended from ancestral species.
i. Natural selection was the mechanism for descent with modification
b. Challenged the notion that the Earth was relatively young and populated by unrelated species.
What is the basic idea of natural selection?
Organisms can change over generations. 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?
a) Overprotection
i. all species tend to produce excessive numbers
ii. this leads to a struggle for existence
b) Individual Variation
i. variation exists among individuals in a population
ii. much of this variation is heritable
What is unequal reproductive success?
a. Natural selection
b. Those individuals with traits best suited for the local environment leave more fertile offspring
What are homologous structures? Know examples we talked about.
Is the similarity in structures due to common ancestry
a) Human forearm, cat forearm, whale flipper, and bat wing
What is biogeography?
a. The study of geographic distribution of species
b. First suggested to Darwin that today's organisms evolved from ancestral forms
What is comparative anatomy?
a. The comparison of body structure between different species
b. Confirms that evolution is a remodeling process
What is comparative embryology?
The comparison of structures that appear during the development of different organisms
What is a fossil? How are fossils formed?
Perserved remnants or impressions left by organisms that lived in the past
Where are fossils found?
Are often found in sedimentary rocks
What type of scientist studies fossils?
Paleontologists
Name 3 examples of natural selection in action
a. Pesticide resistance in insects
b. The development of antibiotic-resistant bacteria
c. Drug-resistant strains of HIV
What is a mutation?
a. Changes in the DNA of an organism
b. Produce genetic variation
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?
a. Shifts the phenotypic "curve" of a population
b. Selects in favor of some extreme phenotype
What is disruptive selection? What does the phenotypic graph look like compared to the original population curve?
Can lead to a balance between two or more contrasting morphs in a population
What is microevolution?
a. Changes in allele frequencies within population
b. Often associated with adaptation
c. Can be measured from one generation to the next
What is macroevolution?
a. Major changes in the history of life
b. Origin of new species
c. Generates biological diversity
Define 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?
a. Species evolve in geographic isolation
b. Usually associated with a geographic barrier, preventing members of two populations from mating with one another
c. Involves independent evolution of the populations after the barrier arises
What is sympatric speciation?
a. Species evolve without geographic isolation - species remain together, with potential to interbreed
b. Probably associated with a genetic barrier due to a single mutational event
c. Important in plants, but not widespread among animals
What special circumstances are required to keep the gene pools separated in sympatric speciation?
a. Segregation of habitat
b. Major alternations in mate recognition or behavior
c. Genetic incompatibility
Know the two models of the Pace of Speciation
Gradualism
a. Mechanism envisioned by Darwin
b. Slow and steady accumulation of small changes leads to production of species over vast stretches of time
c. Leads to the prediction that the fossil record should show numerous forms in a continuous series of
What are prezygotic barriers? Know the 5 types
a. Prevent mating or fertilization between species
b. Can result from natural selection
~Below are the 5 types~
Temporal Isolation
Eastern/ western spotted skunks mate at different times of the year, preventing them from producing offspring even in areas where the two species live together
Habitat Isolation
Even though they occupy the same geographic area, these two species of garter snakes occupy different habitats, preventing them from mating
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
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
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
~Below are the 3 types~
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
Hybrid Sterility
Different species may mate, and produce offspring that are sterile, preventing further mixing of gene pools. Mules are robust animals, but they cannot propagate
Hybrid Breakdown
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 these domesticated rice strains
What is ecology?
The scientific study of the interactions between organism and their environments
What are abiotic factors? Know the 5 examples
a. The nonliving chemical and physical factors in an environment
i. energy source
ii. soil type
iii. climate
- rain fall/ temperatures
iv. wind
v. water
vi. fresh marine
vii. pollution
What are biotic factors? Know some examples
a. The living factors in an environment
i. animals
ii. plants
What are the four levels of ecology? Know what each is concerned with
Organismal ecology, population ecology, community ecology, ecosystem ecology
Organismal Ecology
Concerned with evolutionary adaptations that enable individual organisms to meet the challenges posed by their abiotic environments
Population Ecology
Concerned with populations, concentrates mainly on the factors that effects population density growth
Community Ecology
Concerned with communities, focuses on how interactions between species affect community structure and organization
Ecosystem Ecology
Concerned with ecosystems, focuses on energy flow and the cycling of chemicals among the carious abiotic and biotic factors
What is a habitat?
Specific environments in which organisms live. Reveal patchiness on an even smaller scale
What are 3 types of adaptations that enable organisms to adjust to changes in their environment?
a. Physiological: in mechanisms of temperature regulation, responses by organisms occur quickly.
i. Acclimation: physiological response that is longer term
ii. The ability to acclimate is related to the range of environmental conditions a species naturall
Name 2 types of Aquatic Biomes? What is the salinity of each?
Freshwater biomes: lakes, streams, rivers and wetlands
- usually a salt concentration less than 1%
Marine biomes: oceans, intertidal zones, coral reefs and estuaries
- usually a salt concentration ~3%
What are some uses for freshwater?
Use for drinking water, crop irrigation, sanitation and industry