Evolution Terms Flashcards
Evolution
change occurring in a line over time
Adaptation?
a heritable trait that helps the survival and/or reproduction of an organism in its present environment
Dimorphic trait
traits with 2 distinct forms
Polymorphic trait?
traits with more than 2 distinct form
What are the 3 mutation types
neutral, lethal, and beneficial mutation
What is a neutral mutation?
has no effect on survival or reproduction
What is a lethal mutation?
results in death
What is beneficial mutation?
presents a slight advantage toward survival or reproduction
Mutation
change in DNA patterns
Gene pool
the sum of all the genes in a population
Allele frequency
the rate at which a specific allele appears within a population
Microevolution
change in allele frequency in the gene pool of a population or species
Macroevolution
Large scale evolutionary pattern above the species level
What are 2 types of evolution?
divergent and convergent evolution
Divergent Evolution
changes in body form from a common ancestor
Convergent Evolution
when similar traits evolve independently in species that do not appear to share any recent common ancestry
Homologous structure
- structures in organisms that share the same basic form
- structures appear in separate lineages because they evolved from a common ancestor
Vestigial Structures
structures that exist in organisms but seem to have no apparent function at all
Analogous Structures
look alike but evolve independently
Transitional forms
an intermediate form of an organism linking two other organisms together
How many patterns are there of natural selection and what are they?
3.
directional, stabilizing, and disruptive selection
Directional Selection
an extreme trait is more favorable
Individuals with a trait of one type are selected against
not biologically successful
Stabilizing Selection
an intermediate trait is more favorable
Midrange form of a trait is selected for
adaptive- biologically successful
Disruptive Selection
extremely different traits are more adaptive
Forms at extreme ranges are selected for
adaptive- biologically successful