Burns AP Biology 7.1-7.13

Change in a kind of organism over time; process by which modern organisms have descended from ancient organisms.

A natural process resulting in the evolution of organisms best adapted to the environment.

-several conditions that must be met for evolution by natural selection

the struggle between organisms to survive in a habitat with limited resources

-space, mates, food, nutrients and light

Any difference between individuals of the same species.

Changes in physical structure, function, or behavior that allow an organism or species to survive and reproduce in a given environment.

Ability of an organism to survive and reproduce in its environment

the number of offspring an individual produces and rears to reproductive age; an individual's genetic contribution to the next generation

-comp. of evolutionary fitness

the ability of a trait to be passed down from one generation to the next

-more success=more passed down

environmental conditions that select for certain characteristics of individuals and select against other characteristics (abiotic/biotic factors)

-disease,predators, climate, and food

Breeding organisms with specific traits in order to produce offspring with identical traits.

-can lead to more or less diversity over time

Process by which unrelated organisms independently evolve similarities (analogous) when adapting to similar environments

when two or more species sharing a common ancestor become more different over time

A change in the allele frequency of a population as a result of chance events rather than natural selection.

-nonselective process in SMALL pop

-bottleneck effect (large diverse to small pop)

the movement of some individuals of a species from one population to another (exchange of alleles)

-can increase of decrease genetic diversity over time

Genetic drift that occurs when a few individuals become isolated from a larger population and form a new population whose gene pool composition is not reflective of that of the original population (different from original)

characteristics of a habitat or land area

environmental features of the Earth over time
-fossils show patterns of evolution and changes to the environment over time

phenotypes of species

chemical composition of living organisms
-comparison of molecules like DNA and proteins

calculations and statistics
-models and simulations illustrate and support evidence

variation was present in common ancestry

Ex:The bone structure of human arms, cat legs, horse legs, bat wings, and dolphin fins (internal)

reduced/obsolete feature that serve little to no purpose

Ex:The bone structure for legs in some snakes, the hip bone structure in whales, and the human tailbone

evolved independently in different species due to similiar enviornment conditions/selective pressures (no common ancestor)

refers to the creation of new species (diversity of life forms)

species occupy different habitats and rarely come in contact
-prezygotic barrier

species breed during different times of days, seasons, or years
-prezygotic barrier

species have different courtship behaviors or mate preferences
-prezygotic barrier

reproductive structural differences PREVENT successful mating and reproduction
-prezygotic barrier

sperm of one species may not be able to fertilize the eggs of another species
-prezygotic barrier

mating results in a zygote, but incompatibility may stop the development of the zygote

hybrid offspring mature but are sterile as adults

Some first-generation hybrids are fertile, but when they mate with another species or with either parent species, offspring of the next generation are feeble or sterile

individuals from same population isolated geographically for a LONG time, result in new SPECIES
-no gene flow
-separation could cause different selection pressures

evolution of a new species from reproductive isolated ancestral populations
-no geographical barrier=genetic mutations
-polyploidy
-can result from sexual selection or habitat differentiation

evolution occurs RAPIDLY after a long period of stasis

Hint: A period is a stopping point

evolution occurs slowly over hundreds, thousands, or millions of years

Hint: Slowly progressing or…

the evolution of new species that ALLOW empty ecological roles to be filled (increased speciation)

a diagram used to show evolutionary relationships amongst species

where leaves are attached (recent common ancestor)

A family tree that shows the evolutionary relationships thought to exist among groups of organisms

trait that appears in recent parts of a lineage, but not in its older members (not present in outgroup)

when two or more species sharing a common ancestor become more different over time
-homologous structures (same inside)

occurs when organisms that are not closely related evolve similiar traits
-similiar outside and different inside (no common ancestor)

applying the simplest, most obvious way with the least number of steps

Marine algae abundant; colonization of land by diverse fungi, plants, and animals

Hint: Hordeauves

Age of Fishes

Ex: Think of the Indian neighborhood in Chicago

Period from 286 million through 245 million years ago. Deserts become larger in tropical regions. The supercontinent Pangaea forms as all continents joined together. Reptiles become dominant on land. Warm-blooded reptiles appear. Mass extinction of many marine invertebrates, including trilobites.

Hint: Everyone in the 80s wanted this

Part of the Mesozoic Era, the period when dinosaurs first appeared. (248-213 million years ago)

Hint: Rhymes with Jurassic

Period from 144 million to 66 million years ago. Continents move toward their present-day positions as South America splits from Africa. Widespread volcanic activity occurs. First flowering plants appear. Dinosaurs, including Tyrannosaurus rex, dominate. First snakes appear. Mass extinction at the end of the period causes disappearance of many land and marine life forms, including dinosaurs.

Hint:Rhymes with Bodacious

A trait shared by all members of a group through a common ancestor not just one organism