You see parents the biological evidence was pointing direct to the Thimerosal and vaccines as the cause of Autism, in fact the IOM ruled on the Biological plausibility in 2001 and found it was biologically plausible that vaccines was causeing Autism.

FORBES: Why Salon's Autism Retraction Matters

From the use of surrogate endpoints (based on biological plausibility and the results of preclinical studies) to the distinction between correlation and causation, confounding (whether the effect size is too large to be explained away by confounding), and the hypothesis-generating nature of the inferential process.

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