Evolution Exam Flashcards
Most chile varieties grown in New Mexico are descended from the same plant species. These varieties were produced by:
Artificial Selection
Evolution is detected in
Populations
Which is not homologous?
wing of a fly
Which of the following represents a pair of homologous structures?
the arm of a human and the flipper of a dolphin
In a population that is in equilibrium, the frequency of one allele is 0.4, what is the frequency of the other allele?
0.6
The frequency of one allele is 0.4, what is the frequency of individuals homozygous for this allele?
0.16
Hardy-Weinberg Principal= frequency of homozygous individuals for an allele (p^2) is found by squaring the allele frequency
0.4^2=0.16
Frequency of the recessive allele is often referred to as
q
Which agent of evolution happens when individuals migrate into a new population and breed?
Gene flow
Which is an example of balancing selection?
Heterozygote Advantage
What type of selection eliminates extreme phenotypes?
Stabilizing
What process creates new variation?
Mutation
Which describes natural selection?
a mechanism of evolution where organisms with traits better suited to their environment tend to survive and reproduce more successfully, leading to the increase of those traits in future generations.
Consider genetic drift- how are breeding individuals chosen?
Random selection
Population size going through extreme decline is called ______.
Bottleneck
When some individual split off from a large population and start a new one, this is called ______.
The founder effect
If individuals choose mates that have similar phenotypes to themselves this is called
Positive assortative mating
Cactus has reduced leaves that prevent water loss. Which evolution mechanism creates adaptations?
Natural selection
Species described as different by physical traits are using which concept?
Morphological
What type of data is still needed to support two species of African Elephant?
Biological Species Concept
Male fireflies give species specific flashes to females. This isolation is called
Behavioral Isolation
Evolution
Change over time
Evolution biologically
Change in phenotype, allele or genotype frequencies over time.
What is required for evolution to happen?
1.Population- rather than an individual/lineage
2. With Variation- phenotype/genotype
3. Inheritance of Variation
4. Differential Reproduction-implies species can survive to reproduce.
Artificial Selection
Selection in the hands of humans (For example: dogs)
Homologous Characters
The same structure owing to inheritance to a common ancestor
Agents of Evolutionary Changes
Selection, Mutation, Migration, Inbreeding, and Genetic Drift
Analogous Characteristics:
Traits that served a similar function in different organisms but evolved differently. These result from convergent Evolution
Ex: wings of birds and insects or body of dolphin and shark
How does homology illustrate evolution?
Organisms with common ancestry may show similar structures.
Non-Random mating
Positive assortment mating- choosing like individuals
Negative assortment mating- choosing different individuals
Gene flow
Changes allele and genotype frequency by introducing alleles
Genetic drift
Chance alterations of gene frequencies: Random selection of individuals survive to mate and contribute to the next generation
Mutation
Alterations in an organisms DNA, heritable and makes new alleles
happens very slowly
Selection
Responsible for adaptations to the environment.
Stabilizing Selection
Mean stays the same, distribution changes (narrower)
Directional Selection
Selection for an extreme phenotype (mean changes, distribution same)
Disruptive selection
Two extreme phenotypes (mean stays the same, distribution changes (two peaks))
Balancing Selection
keeps variation in populations
Heterozygote Advantage
Individuals with both alleles are selected for- keeping
both alleles in the population. Example: sickle cell polymorphism in populations where
malaria is important.
Frequency dependent selection
If the frequency of an allele is high, there is selection against that allele
Sexual Selection
Females invest more in offspring than males
Egg is bigger than sperm
Intersexual Selection
Gaudy genotypes and extreme behaviors
Females choosing males based off that
Intrasexual Selection
Male-male competition
Founder effect
Reduced diversity when a population descended from a small number of ancestors
Adaptations
Caused by natural selection, makes them more successful in surviving and reproducing, higher frequency in the next gen
Cryptic Coloration
Camouflage basically
Structural Adaptation
Physical changes in organism for survival
ex: ducks webbed feet to swim
Negative frequency dependent selection
One allele frequency is high and selection is against it, the frequency goes down and the other allele frequency is high
Speciation
Process by which one species splits into two or more species
Biological Species Concept
A group of population whose members have the potential offspring to reproduce viable fertile offspring
Morphological Species Concept
Species are identified based physical traits like size and shape
Ecological Species concept
Identified by ecological niche, focusing on unique adaptations
Pre-Zygotic Reproductive Barriers
Geographic-species life in diff places
Habitat Isolation-animals in diff habitats rarely meet
Temporal Isolation-breeding occurs at diff times of day or season
Behavior Isolation-diff courtship rituals or behavior
Mechanical Isolation- Non-compatible reproductive organs
Gametic Isolation
Sperm not able to fertilize egg of another species
Post Zygotic Reproductive Barriers
Reduced Hybrid Fertility- offspring are sterile after mating
Viability- mating occurs but no offspring
Breakdown- behaviorally ecologically or morphologically messed up
