Based on what I have seen in my classes this fall, I
recommend that you always have multiple trios being mated in your lab class (rather than one mating in which you take
lots of children).
In the mating of the two fathers to the mother, ideally
there would be a 50/50 chance of any given Child being progeny of one or the
other. However, it looks like there
tends to be bias in individual matings. I
have taken the extra seeds from the matings the students in my general biology lab
did this fall and sprouted them. Based
on color markers, it appears that in any given mating most of the children come
from one father, but which father is overrepresented is random. In other words, sometimes most of the
children are from Alleged Father #1 and other times most of the children are
from Alleged Father #2. If there are
several matings going on in lab, then overall the students will see both
possibilities. However, if you did one paternity dispute and
got lots of children, you probably wouldn’t get very satisfying results.
How is this happening?
I assume that even though the students collect pollen from both fathers
on one swab, there is a tendency to get more pollen from one father (but which
one appears to be random). Either one is
shedding more at the time of mating or they just spend a little more time on
the anthers of one father than the other.
