We introduce a population genetics model in which the operators
are effectively computable -- computable in polynomial time on
Probabilistic Turing Machines. We shall show that in this model
a population can encode easily large amount of information
from enviroment into genetic code. Then it can process the
information as a paralel computer. More precisely, we show that
it can simulate polynomial space computations in polynomially
many steps, even if the recombination rules are very simple.