Speciation
In a hypothetical population of parrots, some individuals prefer to eat one type of fruit and another group prefers to eat a different type of fruit. Over many generations, as these two groups of parrots exclusively fed exclusively on their fruit they also began to develop unique behaviors that distinguished them from each other. Eventually these two groups diverged from each other when they would no longer interbreed. What type of reproductive isolation is this?
Behavioral Isolation
Triple Play
In normal natural selection, we see a bell curve or a "normal curve". What are the other 3 patterns of natural selection?
Stabilizing, Disruptive, Directional
What occurs when there is random changes in allele frequencies from generation to generation?
Genetic drift
Two species have DNA sequences that differ by 4 mutations. If mutations occur at a rate of 1 mutation every 2 million years, how long ago did these two species likely share a common ancestor?
8 million years ago
Define Evolution in genetic terms.
Changes in allele frequencies from generation to generation.
A group of lizards wash up on an island after a major storm. These lizards ultimately adapt to their new surroundings and become an entirely new species after many generations. What type of reproductive isolation did these lizards experience?
Geographical Isolation
A cat with better claws for climbing would have a(n) ____ over cats that did not have the same adaptation.
advantage
A population of mice are 50% Black and 50% white. After a fire, their natural habitat is left charred. How do you think this would affect the allele frequency of the black and white alleles?
Black alleles will increase in frequency.
White alleles will decrease in frequency.
If big cat species A and B are more genetically similar to each other than both are to species C, what does that say about their evolutionary relationship?
That species A and B are more closely related than either are to species C.
or
Species A and B shared a more recent common ancestor with each other than either do with species C.
What is it called when a small founding population establishes a new colony in a new geographic area.
Founder's Effect
Two species of fireflies with identical geographic ranges reproduce at different times. One at night and one in the day. What types of isolation are these two species experiencing?
Temporal Isolation
Human babies that have a low birthweight may be underdeveloped and have a higher risk of health complications.
Too high birthweights can lead to difficulties during delivery and an increased risk for both baby and mother.
As a result, natural selection favors average-sized babies with higher survival rates.
What kind of selection do human birthweights experience?
Stabilizing selection
Calculate the allele frequency of a population of horses with 12 homozygous black (BB), 24 heterozygous black (Bb), and 14 brown (bb).
B = .48
b = .52
Scientists find that two bird species have very similar DNA except for 6 base differences. If the mutation rate is 1 base difference per 5 million years, estimate how long ago the birds shared a common ancestor.
30 million years ago
There are 3 ways to introduce a new gene to a population. What are they?
Mutation, Genetic Recombination, Lateral Gene Transfer
Northern and Southern elephant seals have similar genetics and mating rituals. However they have different ranges and reproduce in different months of spring. What modes of isolation do these species experience?
geographic and temporal
What does it mean to be in genetic equilibrium?
No evolution is occurring.
or
Allele frequencies are static (not changing).
Calculate the allele frequency of this population of 950.
Homozygous dominant (SS): 380
Heterozygous (Ss): 475
Homozygous recessive (ss): 95
S = .65
s = .35
What two things do you need to make a molceular clock?
The rate of mutation for two different species
The DNA sequences of two species
When looking at the allele frequencies for a particular gene, how can we know if natural selection is taking place?
If the frequency of one allele increases or decreases over time.
What type of isolation was primarily experienced by the founding population of Darwin's finches?
Geographic Isolation
Daily Double
What are 3 of the 5 conditions that must be met for true genetic equilibrium to occur?
Random mating
(Infinitely) Large population
No Migration
No Mutation
No Natural Selection
Calculate the allele frequency of this population:
Homozygous dominant (MM): 440
Heterozygous (Mm): 550
Homozygous recessive (mm): 110
M = .65
m = .35
Daily Double
Scientists have long debated over whether hyenas were in the same evolutionary family as dogs or cats. How can the analysis of the Hyena's genome provide evidence for their classification.
Compare the genomes of hyenas to dog species and cat species and determine which two shared a more recent common ancestor with hyenas.
Make a molecular clock to see which group hyenas are more closely related to.
How do the allele frequencies of the surviving population experiencing a Bottleneck effect and the founders of a new region experiencing the Founders effect compare?
Both of these populations have different allele frequencies from the original population.