We construct a probabilistic model with the aid of the Markov chain formali
sm to describe and give a physico-chemical justification to an oligomerizat
ion process of a set of amino acids under certain prebiotic conditions. Suc
h chemical process shows a remarkable bias in the polymer products that our
model can explain. Some predictions and limitations are also discussed. (C
) 2000 Elsevier Science Ireland Ltd. All rights reserved.