The traditional view in paleontology is that there were five mass extinctions of species in the history of the earth. Interestingly, there is now a contrarian view, supported by quite a bit of evidence, that the theory of mass extinctions may well be incorrect. This happens in science all the time. Just think of the anti-fat advice in the medical community where it turns out that it’s actually processed carbohydrates and sugars causing heart disease and obesity. Or, in software engineering, the transition from process heavy models like CMMi to agile practices as the “best” way to build software. The challenge is that scientists are humans too and we all seek to interpret the data and explain it based on a paradigm that we believe to be true. Then there is a paradigm revolution and we move on to a new paradigm and use that to explain the date, often leading to very different results. The process of science is to continuously seek better explanations and the history of humanity over the last centuries shows that it works. But we should be careful to not get stuck in old paradigms. So, what paradigm shift are you going through today?