A student proposes that left-handedness is a recessive trait that is therefore hidden in much of the human population. A survey of a class of 36 students finds that 27 (0.75) are right-handed and 9 (0.25) are left-handed. Using the Hardy-Weinberg formula, what would the expected genotypes and allele frequencies be in this theoretical population?
0.75 homozygous dominant and 0.25 homozygous recessive, and a 3-to-1, right-to-left handed allele ratio in the population.
0.25 homozygous dominant, 0.50 heterozygous, and 0.25 homozygous recessive, and a 0.75 dominant allele frequency and a 0.25 recessive allele frequency.
0.25 homozygous dominant, 0.50 heterozygous, and 0.25 homozygous recessive, and a 0.5 allele frequency for each allele.
0.50 homozygous dominant, 0.25 heterozygous, and 0.25 homozygous recessive, and a 0.5 allele frequency for each allele.
They cannot be estimated using these limited data.
Our domesticated honey bee—originally from Europe—is slow to sting, requires abundant flower nectar, gets up late in the morning, and stores much honey but only produces enough new brood to swarm once a year. Because the European honey bee was performing poorly as a honey producer in South America, the African subspecies was imported in a breeding experiment. The African honey bee formed small nests, foraged earlier and on smaller nectar sources, produced less honey stores and more brood, swarmed four or five times a year, and was fast to sting. However, when the African queens escaped, the two populations interbred and the African genotype spread several hundred miles north each year. Surprisingly, a hundred miles behind the expanding range of the African honey bees, the European and hybrid strains died out and the bees were essentially 100 percent African. How would this be explained in evolutionary genetics terms?
Gene flow is not occurring and therefore these are two separate species.
This is a natural consequence of the Hardy-Weinberg equilibrium.
Obviously the African bee genes are dominant over the European honey bee alleles.
Gene flow is occurring between these subspecies but the African bee is 'ecologically better suited".
This can be understood as a classic case of genetic drift.
Order these major taxonomic categories into an increasingly inclusive hierarchy.
genus, species, class, order, family, domain, kingdom, phylum
species, genus, family, order, class, phylum, kingdom, domain
domain, kingdom, phylum, class, order, family, genus, species
class, order, family, genus, species, kingdom, phylum, domain