This weeks question on genitics. (Senior Scientific)

[gavin]

Just feel that I should congratulate Jane S on being spot on in every way. The question was good, and brown eyes (in this hypothetical example) come with yy which is at a frequency of 0.15 (15%) in the cross.

I do these things with proportions.

Gametes from the heterozygous female:

Y - 0.5 (lets say gamete i)
y - 0.5 (gamete ii)

Gametes from the drones:

Y - 0.7 (gamete iii)
y - 0.3 (gamete iv)

The combinations and proportions after fusion of the gametes at random are:

i x iii ie 0.5 x 0.7 = 0.35 as YY
i x iv ie 0.5 x 0.3 = 0.15 as Yy
ii x iii ie 0.5 x 0.7 = 0.35 as Yy
ii x iv ie 0.5 x 0.3 = 0.15 as yy

As Jane says, that is easier in a table of female x male gametes.

Only yy are brown eyed and they are at 0.15 or 15%. The rest (85%) are yellow-eyed.

As a check add up the proportions and they come to 1.0.

[prakel]

The follow-up generations of Murray's imported bees are getting darker - so, it must be a complicated soup of genes at work there.
Kitta

I think that it must be time for some follow up research on that done by Woyke and, previously, Roberts. No one's questioning their results but there's clearly a different result in practice -which those of us that have tried to maintain orange colouration have seen constantly. No question that the population tends to shift towards a darker type.

[Mellifera Crofter]

Ps: anyway, if I pretend the queen is yellow-bodied rather than yellow-eyed, I agree with Jane’s answer.

But that might be wrong too. I think yellow-bodied is also recessive, which is why C4U told us imported bees soon revert to dark bees).


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