Evolution (plants) Flashcards
Evolution
What is a theory
A hypothesis that has been rigorously tested
Evolution
What is a law
A universal truth
Evolution
Definition
The change in allele frequencies in a population overtime
Evolution
Allele=
Form of a gene
Evolution
Frequency=
How often something occurs
Evolution
Population=
All members of a species that interact
Evolution
What are the 4 ways to change allele frequencies
Natural selection
Mutation
Genetic drift
Gene flow
Evolution
Natural selection means
The best suited for the environment have a higher probability of survival and production
“Survival of the fittest”
Evolution
What are the 3 modes of natural selection
Directional selection
Disruptive selection
Stabilizing selecton
Evolution
Directional selection means
1 extreme phenotype is favored
Evolution
Disruptive selection means
Both extreme phenotypes are favored
Evolution
Stabilizing selection means
Average phenotype is favored
Evolution
What are the 3 general trends of natural selection
Coevolution
Adaptive radiation
Convergent evolution
Evolution
Coevolution means
One species evolves in response to another species’ evolution
Evolution
Adaptive radiation means
Parts of a lineage acquire different characteristics to adapt to different environments
Evolution
Convergent revolution
Distantly-related lineages acquire similar characteristics to adapt to similar environments
Evolution
Mutation means
An error in copying DNA / reproductive cells
Evolution
What is the only way to get new alleles
Mutation
Evolution
Mutations are often ___ -
Silent, not expressed in phenotype
Evolution
Mutations are rarely (5)
Fatal Change protein shape 3rd codon Beneficial Rare occurence 0.1-100 mutations / genome / generation
Evolution
Genetic drift means
Allele frequencies change by chance
Evolution
Gene flow means
Movement of alleles from one population to another
Rates of Evolution
Punctuated equilibrium means
Years of rapid evolution followed by many years of no evolution
Rates of Evolution
Gradualism menas
Constant, tiny evolutionary events
Speciation
Definition
Formation of new species
Opposite of extinction
Speciation
Population must be ___ ___
Genetically isolated
Speciation
What are the 2 categories
Pre-zygotic
Post-zygotic
Pre-zygotic means
Before the zygote is formed
Speciation
3 types of pre-zygotic isolation
Geographic isolation
Ecological isolation
Mechanical isolation
Speciation
Geographic isolation means
Physical barrier prevents isolation
Speciation
Ecological isolation means
Bloom times not aligned
Speciation
Mechanical isolation means
Exine doesnt fit into the receptors of the stigma
Speciation
Post-zygotic means
After the zygote is formed
What are the 3 types of post-zygotic speciation
Zygote death due to chromosomal mismatch
Hybrid sterility
Reduced hybrid fitness
Speciation
What is polypolidy
Increased survival due to redundant genes
Speciation
What are the 2 types of polyploidy
Allopolyploid
Autopolyploid
Speciation
Allopolyploid means
A hybrid of 2 different species
Speciation
Autopolyploid
A hybrid of 2 different populations of same species
