I describe an analytical approximation for calculating the short-term probability
of loss of a chromosome under the neutral Wright-Fisher model with recombination. I also
present an upper and lower bound for this probability. Exact analytical calculation of this
quantity is difficult and computationally expensive because the number of different ways in
which a chromosome can be lost, grows very large in the presence of recombination.
Simulations indicate that the probabilities obtained using my approximate formula are
always comparable to the true expectations provided that the number of generations remains
small. These results are useful in the context of an algorithm that we recently developed
for simulating Wright-Fisher populations forward in time. C++ programs that can efficiently
calculate these formulas are available on request.