Smooth energy: Cosmological constant or quintessence?

For a flat universe presently dominated by smooth energy, either cosmologic al constant (LCDM) or quintessence (QCDM), we calculate the asymptotic coll apsed mass fraction as a function of the present ratio of smooth energy to matter energy, R-o. Identifying the normalized collapsed fraction as a cond itional probability for habitable galaxies, we observe that the observed pr esent ratio R-o similar to 2 is likely in LCDM, but more likely in QCDM. In verse application of Bayes's theorem makes the anthropic principle a predic tive scientific principle : the data imply that the prior probability for R -o must be essentially flat over the anthropically allowed range. Interpret ing this prior as a distribution over theories lets us predict that any fut ure theory of initial conditions must be indifferent to R-o. This applicati on of the anthropic principle does not demand the existence of other univer ses.