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Zoe-b
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Homework Statement
According to genetic linkage theory, observed frequencies of four phenotypes
resulting from crossing tomato plants are in the ratio 9/16 + a : 3/16 - a : 3/16 - a : 1/16 + a.
In 1931, J.W. MacArthur reported the following frequencies:
Observed
Phenotype frequency
Tall, cut-leaf 926
Tall, potato-leaf 288
Dwarf, cut-leaf 293
Dwarf, potato-leaf 104
Total 1611
Write down the likelihood of a given these observations. Find the maximum likeli-
hood estimate of a, use it to calculate expected frequencies for the four phenotypes
and compare them with the observed frequencies. Does genetic linkage theory look
plausible?
Homework Equations
likelihood of a data set (x1...xn) occurring is the product of fX(x), if Xi are independent. Then I could find max likelihood etc as usual
The Attempt at a Solution
Basically I just cannot start this problem at all. I have only ever found likelihood before as a function producing one value, here I seem to want to find the probability that the ratio is b:c:d:e which I have no idea how to do. Also surely I need to know something about the variance of a? At least then I could write down a probability to do with each bit of the ratio?
Sorry if I'm not making much sense/if this is obvious but I have spent a long time attempting this with no luck. Google hasn't helped at all either..