John Timmer's reporting on the rise and fall of the hypothesis that XMRV causes chronic fatigue syndrome is the best I've seen so far on the topic: "How a Collapsing Scientific Hypothesis Ended in an Arrest"
Something worth reminding: basic analysis of lab samples is often based on evolutionary theory:
The key piece of evidence came in an evolutionary analysis of XMRV origins. Researchers found that the most diverse group of XMRV sequences come from a single prostate cancer cell line called 22Rv1 that was grown in lab dishes. All of the XMRV sequences isolated from patients clustered within the evolutionary tree derived from the cancer cell line, meaning the ancestors of the viruses supposedly found in patients had all come from a single lab-grown cancer cell line. The clear implication is that the sequences came from the cell lines rather than patients.
There is much to say about the errors, retractions, and fraud involved in the story. I'll just point out that some of the key revelations of fraudulent analysis came from the blog erv, whose author Abbie Smith first reported that figures from a Science paper had been used in conference talks, relabeled with entirely different contexts added.