AP Biology Exam Review

Evolution

Paleontology Biogeography Embryology comparative anatomy homologous structures analogous structures vestigial structures molecular biology artificial selection

Evidence

over-production inherited variation Competition Adaptations Fitness survival of the fittest Eaccumulation of advantageous traits

Natural Selection

stabilizing selection, directional selection, disruptive selection, sexual selection

• genetic equilibrium • infinitely large population • no natural selection • no mutations • no gene flow (no migration) • random mating

• frequency of alleles: p + q = 1 • frequency of genotypes or individuals: p2 +

2pq + q2 = 1 •

Hardy-Weinberg Equilibrium

• genetic drift: founder effect, bottleneck

• natural selection, gene flow, mutation, non-random mating, sexual selection

non-equilibrium

• adaptive radiation - the evolution of ecological and phenotypic diversity within a rapidly multiplying lineage.[1] Starting with a recent single ancestor, this process results in the speciation and phenotypic adaptation of an array of species exhibiting different morphological and physiological traits with which they can exploit a range of divergent environments.

Speciation

allopatric: geographic isolation

sympatric: reproductive isolation

Speciation

Factors which prevent individuals from mating. Geographic isolation: Species occur in different areas, and are often

separated by barriers. Temporal isolation: Individuals do not mate because they are active at

different times. This may be different times of the day or different seasons. The species mating periods may not match up. Individuals do not encounter one another during either their mating periods, or at all.

Ecological isolation: Individuals only mate in their preferred habitat. They do not encounter individuals of other species with different ecological preferences.

Behavioral isolation: Individuals of different species may meet, but one does not recognize any sexual cues that may be given. An individual chooses a member of its own species in most cases.

Mechanical isolation: Copulation may be attempted but transfer of sperm does not take place. The individuals may be incompatible due to size or morphology.

Gametic incompatibility: Sperm transfer takes place, but the egg is not fertilized.

Prezygotic Isolation

Genomic incompatibility, hybrid inviability or sterility.

Zygotic mortality: The egg is fertilized, but the zygote does not develop.

Hybrid inviability: Hybrid embryo forms, but is not viable.

Hybrid sterility: Hybrid is viable, but the resulting adult is sterile.

Hybrid breakdown: First generation (F1) hybrids are viable and fertile, but further hybrid generations

Postzygotic Isolation

• divergent evolution - the accumulation of differences between groups which can lead to the formation of new species

• convergent evolution - describes the acquisition of the same biological trait in unrelated lineages.

Patterns of Evolution

These two succulent plant genera, Euphorbiaand Astrophytum, are only distantly

related, but have independently convergedon a very similar body form

analogous structures - • parallel evolution • coevolution

macroevolution: gradualism vs, punctuated equilibrium

• earth & atmosphere formed: low or no O2 • complex molecules in primordial seas,

monomers, polymers • organic molecules & early cells formed • heterotrophic prokaryotes • autotrophic prokaryotes: O2 & ozone layer

formed • eukaryotes formed, endosymbiotic theory • mitochondria & chloroplasts have own DNA,

reproduce independently (~binary fission), have ribosomes similar to bacteria &

cyanobacteria

Origin of Life