1. Flowering plants that become established on islands often have a higher incid
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1. Flowering plants that become established on islands often have a higher incidence of self-pollination (selfing). The Monkeyflowet. Minwls guttaus (native to Western North America), has recently become in established on islands along the coasts of California. A researcher interested in how selfing might contribute to establishment of flowering plant populations has recently genotyped 500 different plants from Catalina Island at an A/G nucleotide polymorphism within the NACI gene. Here are the observed genotypes counts: AA homozygotes: 68 AG heterozygotes: 64 GG homozygotes: 368 To (a) Is the Catalina Island population at Hardy-Weinberg equilibrium at the NACI locus? Perform a statistical test of this hypothesis. Please make sure you clearly state your conclusion in a complete sentence and provide statistical support for this conclusion. (14 points; show your work clearly for full credit) (b) The inbreeding coefficient at the NACI locus of mainland Monkeyflower populations is zero. What is the inbreeding coefficient at the NACI locus in the Catalina Island population? (4 points, show your work clearly for full credit). #1 continued, write your answer from part (b) here I calculated the inbreeding coefficient to be: (e) What does your answer to part (b) suggest about the biology of island establishment by flowering plants? (4 points; 1-2 sentences)Explanation / Answer
Ans 1.
The Hardy-Weinberg model consists: allele frequencies and genotype frequencies which remains constant generation after generation if there is no migration, mutation, selection or random drift.
p + q = 1
By applying the formula the values calculated are: p= 0.2, q= 0.8,2, pq= 1.0294
In a diploid organism with alleles A and G at a given locus, there are three possible genotypes: AA, AG, and GG. If we use p to represent the frequency of A and q to represent the frequency of G, we can write the genotype frequencies as (p)(p) or p2 for AA, (q)(q) or q2 for aa, and 2(p)(q) for Aa. The equation for genotype frequencies is
p2+ 2pq + q2 = 1
0.4+1.024+0.64= 2.064
Hardy Weinberg equilibrium does not exist in this example as the population shows the presence of mutation .this shows that the cataliana island population is not in equilibrium with the Hardy Weinberg law
With this calculated value we can say that when chi square test was applied it was significant p=0.1 which explains that the population is not in equilibrium
Ans 2.
Inbreeding coefficient at NACL locus of mainland monkey flower population is zero so, According to Crow & Kimura.
pAG= 2?n?((1+fA)/(1+fO))½
Genotype Frequency
AA p^2*(1-f) + p*f
AG 2 pq(1-f)
GG q^2*(1-f) + q*f
f is the inbreeding coefficient. When, f=0 we have the standard HW( hardy-weinberg ) proportions. When f=1 there are no heterozygous AG.
N=0 by placing the value the in formula:
It comes 20= 1 the calculated inbreeding coefficient at NACL locus is 1
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