Evolution
A short-term response to an environmental change
Acclimation
True or False: A predator must be present in an environment for a population to evolve?
False
What is the formula to calculate genotypic frequencies?
p^2 + 2pq + q^2 = 1
What type of selection leads to sympatric speciation?
Distruptive selection
True or False: A phylogenetic tree is a hypothesis; we can never be sure which tree is the true ancestral lineage.
True
Changes in the population's’ allelic frequency due to a
random chance event
Genetic drift
Why are adaptations not perfect? (hint: there are 2 reasons!)
The genotypic frequencies of birds changed from one generation to the next generation. However, has this population evolved?
Yes, any changes to genotypic/allelic frequencies means evolution has occurred
What species concept would be hard to apply to organisms that produce asexually, such as bacteria?
Biological species concept
Where are taxa located on a phylogenetic tree?
At the tips of branches
What are the five possible mechanisms of evolution?
Natural selection, genetic drift, gene flow, mutation, non-random mating
What two types of selection does sexual dimorphism give rise to?
Intersexual and Intrasexual selection
What are the five requirements for a population to be in HWE?
No natural selection, no gene flow, no genetic drift, no mutation, mating is random
Allopatric speciation occurred to a population of lizards when sea levels rose and cut off their habitats. However, recently a land bridge appeared (magic!) and gene flow was re-established. The two populations now being able to breed again is an example of what?
Secondary contact
According to this phylogenetic tree, powered flight would be an example of... (refer to slide 5)
Process in which an organism incorporates genetic materials from another without it being its offspring
Horizontal Gene Transfer
What form of selection maintains multiple alleles in a population?
Balancing selection
A population of rabbits are in Hardy-Weinberg equilibrium. The allele for white rabbits (R) has an allele frequency of 0.19, and the allele for black rabbits (r) has an allele frequency of 0.81. What is the percentage of heterozygous individuals in the population?
~ 31%
When a donkey and a horse mate, they can give birth to a viable mule, however, mules are sterile. This is an example of what type reproductive isolation?
Post-zygotic hybrid infertility
Which phylogenetic true is most likely the correct hypothesis, and why? (refer to slide 6)
Tree A due to parsimony
Inbreeding depression leads to what?
Increased homozygosity and the expression of recessive deleterious alleles
What are the four critical components of natural selection?
Variation, heritability, differential survival and reproduction, adaptation
Purple flowers are dominant to yellow flowers. A random sample of 100 flowers was taken from a population in Hardy-Weinberg equilibrium. 9 flowers were yellow and 91 flowers were purple. What is the frequency of the yellow allele in this population?
0.3
Name every type of pre-zygotic isolation that can occur
Mechanical, Temporal, Gametic, Geographic, Behavioral, Ecological
Which phylogenetic tree(s) accurately depicts the relationship between the 3 domains of life, assuming Archaea and Eukarya are more closely related than Bacteria? (refer to slide 7)
1 and 4