Patterns of Evolution Flashcards
What are the broad patterns of evolution that can be observed in nature?
Speciation, Extinction, Gradualism, Coevolution, Punctuated equilibrium, Divergent evolution, and Convergent evolution.
What is speciation?
Speciation is the formation of a new species from an existing species through the process of evolution.
What is necessary for speciation to occur?
For speciation to occur, some sort of isolation must occur between the two groups which causes the gene pools to gradually become different, making reproduction between the two groups impossible.
What is extinction?
Extinction is the elimination of a species.
What are the two types of extinction?
The two types of extinction are Gradual extinction and Mass extinction
Gradual extinction
Elimination that occurs at a slower rate
ex.) changes in climate, natural disasters
Mass extinction
Occurs when a catastrophic event changes the environment suddenly
like a massive volcano, meteor, or tsunami
What is gradualism and can you provide an example?
Gradualism is a slow, constant change over a long period of time.
An example of gradualism is the. gradual evolution of horse limbs, where their legs have changed over time to allow them to run faster.
What is punctuated equilibrium and can you provide an example?
Punctuated equilibrium is bursts of change followed by periods of stability.
An example of punctuated equilibrium is changes to mammal populations during the Mesozoic and Paleozoic eras.
What is divergent evolution and can you provide an example?
Divergent evolution is when a number of different species arise from a common ancestor
example of divergent evolution is adaptive radiation
What is convergent evolution and can you provide an example?
Convergent evolution is when unrelated species evolve to have similar characteristics because they live in similar environments.
An example of convergent evolution is the ability of birds, bats, and insects to fly, even though they do not share any common ancestry.
What is coevolution and how does it occur?
Coevolution occurs when two populations of organisms form a specialized relationship and change in response to each other.
Species
groups of organisms that can successfully interbreed and produce fertile offspring
adaptive radiation
Evolution in populations as a result of a new environment
adaptive radiation happens how?
on a small scale over a shorter period of time
