Simian AIDS was discovered after human AIDS. How do they know the jump didn&#x27;t occur in reverse?<p>Here is the first report of simian AIDS:
&quot;Examination of the species-specific annual mortality rates of macaques at the center during the previous 4 yr showed a significant increase in deaths in 1980 and 1981&quot;
<a href="http:&#x2F;&#x2F;www.ncbi.nlm.nih.gov&#x2F;pmc&#x2F;articles&#x2F;PMC393899&#x2F;" rel="nofollow">http:&#x2F;&#x2F;www.ncbi.nlm.nih.gov&#x2F;pmc&#x2F;articles&#x2F;PMC393899&#x2F;</a><p>Also, it is convenient they do not share the mcmc traces. Based on these settings I bet they were ugly:<p>&gt;&quot;For each data set, at least 3 MCMC chains of 250 million steps were computed. Parameters and trees were sampled every 50,000th step. Samples were combined with LogCombiner (77) and between 10 to 30% of each MCMC chain was discarded as burn-in. MCMC mixing was diagnosed using visual trace inspection and calculation of effective sample sizes in Tracer (77). We report the posterior mean and 95% Bayesian credible intervals for evolutionary parameters.&quot;<p><a href="http:&#x2F;&#x2F;dx.doi.org&#x2F;10.1126&#x2F;science.1256739" rel="nofollow">http:&#x2F;&#x2F;dx.doi.org&#x2F;10.1126&#x2F;science.1256739</a><p>Another thing, they write:<p>&quot;Our estimated location of pandemic origin explains the observation that Kinshasa exhibits more contemporary HIV-1 genetic diversity than anywhere else&quot;<p>This is totally circular. As shown in their figure S2, they used genetic diversity in a region as an indication of earlier presence.