Lecture Test 1 Flashcards
(151 cards)
Sympatric Speciation
Type of speciation that occurs when individuals within a species become specialized for occupying different parts of the environment
ex: fish in the same stream but living in different environments of said stream
Inbreeding
Form of genetic drift that occurs with mating between close relatives that share a large number of alleles. Results in homozygous recessive traits being more prevalent=weaker species
Natural selection
Mechanism of evolution where individuals best adapted to the environment will survive and reproduce at a greater rate than others
Immigration
Form of gene flow that occurs when a population gains alleles when individuals move in permanently
Gene Flow
aka Migration
Mechanism of evolution that occurs with the movement of alleles among populations.
Can be Emigration or Immigration
Adaptation
A trait that enhances an individual’s fitness.
An inherited trait or behavior that enables an organism to survive and reproduce successfully.
Emigration
Form of gene flow that occurs when a population loses alleles when individuals leave it permanently
Sexual Selection
Mode of natural selection that occurs when individuals compete to reproduce
Males will be more colorful and larger (usually) and female will care for young
Directional Selection
Mode of natural selection that occurs when allele frequencies shift in one direction due to environmental influences
Ex: pepper moths blending in with lichen
Genetic bottleneck
Form of genetic drift that occurs when there is a drastic reduction in population size brought about by severe pressure
ex: northern seals having been hunted near extinction
Organic Evolution
Accumulation of genetic changes in populations or organisms through many generations
Disruptive Selection
Mode of natural selection that occurs when extreme forms of a trait are favored and the intermediate forms are selected against
Genetic Drift
Mechanism of evolution that occurs with random changes in allele frequencies over time, brought about by chance alone
What are the three forms of genetic drift
genetic bottleneck
inbreeding
founder effect
Allopatric Speciation
Type of speciation that occurs when a physical barrier separates members of a population that ends gene flow between them
Ex: great wall of china
Sexual dimorphism
Individuals of many sexually reproducing species that have distinct male and female characteristics
Founder effect
Form of genetic drift that occurs when a small number of random individuals start a new population in a new area
Ex: bird taking flowers to a new area. The new area is limited to the flowers brought
the founder effect is most pronounced in….
isolated islands, as it is harder to introduce multiple traits to a remote place
Stabilizing selection
Mode of natural selection that occurs when intermediate forms of a trait are favored while extremes are eliminated
Artificial Selection
Form of natural selection that occurs when humans manipulate the genome of other species by controlling which individuals breed.
Ex: our produce, animal breeds, “designer babies”
What are the 4 mechanisms of microevolution
Mutation
Natural selection
Gene flow
Genetic drift
What are the two mechanisms of macroevolution
Allopatric speciation and Sympatric speciation
Define Microevolution
Small changes within a species over a short period.
Descent with Modification means ___________
Those best adapted to the environment will survive and reproduce to pass the best possible traits to offspring