Natural Selection Essentials
This evolutionary mechanism results when individuals with advantageous phenotypes leave more viable, fertile offspring.
Natural Selection
This random process introduces new alleles into a population.
Gene Flow
A nonselective change in allele frequencies that is strongest in small populations.
Genetic Drift
The Hardy Weinberg model provides this kind of hypothesis for nonevolving population.
null hypothesis
These preserved remains or traces provide direct evidence of past life and evolutionary change.
Fossils
Natural Selection acts on individuals, but this level changes in allele frequencies over time
Population
This meiotic event swaps DNA between non sister chromatids and increases genetic diversity.
Crossing Over
If gene flow increases between two populations, the chance of speciation generally ______.
decreases
In Hardy Weinberg, the equation that must equal 1: p^2 + 2pq + ____.
q^2
A phylogenetic tree's branching points (nodes) represent this:
Divergent evolution
what term describes traits that improve an organisms ability to survive and reproduce in the environment?.
Adaptation
Whether a mutation is beneficial or detrimental depends most on this
Environment
When a few individuals establish a new population and allele frequencies differ from the source population, this is the ______ effect.
Founder
One required condition of Hardy Weinberg: individuals must mate this way.
Speciation occurs when populations become this, preventing gene flow.
Reproductively isolated.
What is the term for the ability of an organism to survive and reproduce in its environment?
fitness (biology)
If a mutation has no effect on phenotype, it is considered this type of mutation (in many contexts).
If a population experiences strong genetic drift, its genetic diversity tends to do this over time.
Significantly redact.
In Hardy Weinberg, the expected heterozygote frequency is this expression
2pq
Speciation in geographically isolated populations is called this.
Allopatric Speciation
This term describes variation that can be passed from parent to offspring and is required for selection to occur.
Heritable Variation
what process during meiosis increases genetic variation by shuffling alleles?
Genetic Recombination.
After a natural disaster drastically reduces a population, the surviving individuals have different allele frequencies than before. What is this effect called.
Bottleneck Effect.
If q = 0.2, the expected frequency of homozygous recessive individuals is this.
.04
Reduced anatomical features with little current function are called these and support common ancestry.
Vestigial Structures.