Natural Selection
The two macromolecules that are compared to determine molecular homologies between species for a specific gene.
What is DNA (nucleotide) sequence and protein - (amino acid) sequence?
Describe the concept of punctuated equilibrium
Evolutionary changes consist of rapid bursts of speciation alternating with long periods in which species remain essentially unmodified.
The disproportionate representation of a certain allele due to a population at one point being reduced to a select few individuals that had a high representation of this allele. The Askenazi Jews are an example of this. During WWII, their populations decreased significantly. By chance the remaining population had a high number of the allele that codes for the deadly disease, Tay-Sachs.
What is bottleneck effect?
How you use the Hardy-Weinberg equations to determine if a population is evolving.
What is p and q change (allele frequency) over time in a population?
Describe the effect of genetic drift on the gene frequencies of a population.
Chance alone can cause significant changes in gene frequencies of small populations.
The increase of beak size in a finch population over time due to a high proportion of large seeds in an ecosystem could be considered an example of this type of selection.
What is directional selection?
The definition of relative evolutionary fitness.
What is the ability to survive and reproduce relative to others within a population?
In corn, yellow kernel color is governed by a dominant allele; white, by its recessive allele. A random sample of 1,000 kernels from a population that is in equilibrium reveals that 910 are yellow and 90 are white. What are the frequencies of the yellow and white alleles in this population? What is the percentage of heterozygous in this population?
What is p=0.7, q=0.3? 42%?
Tigers and lions will interbreed in captivity and produce viable offspring, but they do not interbreed in Asia where their geographic ranges overlap. Which of the reproductive isolating mechanism accounts for this?
behavioral (lions are social in prides - influences mating, while tigers are solitary). Ecological (lions = open grasslands, tigers occupy jungles/forests), or temporal (tigers are nocturnal, lions are diurnal)
Selection that leads to a high proportion of average traits, and selects against extreme traits in a polulation.
What is stabilizing selection?
Why is the amino acid sequence much more strongly conserved than nucleotide sequence when comparing homologous proteins between species?
What is the redundancy of the genetic code - silent mutations in the gene sequence may produce the same amino acid given two different codons - UAU and UAC both code for the same amino acid?
Within a population of butterflies, the color brown (B) is dominant over the color white (b). And, 40% of all butterflies are white. Calculate the frequency of homozygous dominant individuals.
What is 0.135?
Toads in a particular population vary in size. A scientist observes that in this population, large males mate with females significantly more often than small males do. What type of selection does this represent?
Sexual selection (could argue natural if Large males are successful in competing for mates more often than small males are because they have secured a large breeding territory.
What are the 5 points of Darwin's theory of natural selection (VICDA model)
Variation between members of a population, These differences are Inherited, Competition for limited resources, Differential survival and reproduction, Adaptation - traits that enhance survival and reproduction become more common in a population over time.
In corn, yellow kernel color is governed by a dominant allele; white, by its recessive allele. A random sample of 1,000 kernels from a population that is in equilibrium reveals that 910 are yellow and 90 are white. 10 years later, the population size is 10,000. What is EXPECTED number of heterozygous individuals this population?
42% of 10,000 = 4,200 heterozygotes.
3 pieces of evidence for the endosymbiotic theory
Name the 5 HW Equilibrium conditions
No mutations, random mating, no natural selection, super huge population size, no gene flow (immigration or emigration of individuals to change the gene pool).