Dating The Past
This method gives a fossil's exact numerical age by measuring the decay of radioactive isotopes.
Absolute Dating
The process where unrelated species develop similar features, like fins on a shark and a dolphin, due to similar environmental pressures.
Convergent evolution
The name for structures, such as the human arm and bat wing, that are similar because they were inherited from a common ancestor.
Homologous traits
The type of isolation that occurs when populations are separated by a physical barrier like a mountain range or a river.
Geographic Isolation
In this dating method, the age of a fossil is determined by its position in rock layers
Relative Dating
The pattern where a single ancestral species evolves into multiple diverse species, each adapted to a unique environment.
Divergent evolution
The type of structures that are the result of convergent evolution. (Hint: They serve a similar function but have different origins)
Analegous structures
The type of reproductive isolation that separates Eastern and Western Spotted Skunks because they mate at different times of the year (fall vs. spring).
Temporal isolation
If a sample started with 16g of Carbon-14 (half-life 5,700 years) and now has 4g, this is the number of half-lives that have passed.
2
The type of evolution shown when a flower develops a longer tube and an insect develops a longer proboscis in response to each other.
Coevolution
The model of evolutionary change that suggests evolution is constant and steady, not in sudden bursts.
Gradualism
The pattern of natural selection that favors the average trait and works against the extreme traits, such as favoring medium-length tails in a mammal population.
Stabilizing selection
Calculate the age of a fossil if it initially had 32g of Carbon-14 and now has 8g, given the half-life is 5,700 years.
11,400 years
The term for when a change in a population's traits is caused by an environmental pressure (like pollution) selecting for one extreme trait.
Directional Selection
The opposite model to Gradualism, which describes evolutionary change as bursts of rapid change followed by long periods of stability.
Punctuated Equilibrium
The process where a new species evolves from another, already existing species.
Speciation