Big Think What are the chances of YOU existing? A biologist explains | Sean B. Carroll
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Oct 3, 2025 In this engaging discussion, biologist Sean B. Carroll reveals that your existence is a cosmic fluke—crafted through a series of extraordinary accidents. He explains how a 6-mile asteroid wiped out dinosaurs, paving the way for mammals and eventually humans. Carroll highlights the incredible odds of human life, suggesting that every individual is a unique product of chance. Life, he argues, is not about destiny but about improbability, shaped by pivotal moments that could easily have turned out differently.
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Life As A Series Of Accidents
- Sean B. Carroll argues life's history looks like an "incredible series of accidents," not a directed progression.
- Scientists in recent decades recognize that many contingent events shaped the world we know today.
The Yucatan Asteroid Reset
- Sean describes a six-mile-wide asteroid hitting the Yucatan 66 million years ago and causing global devastation that erased large reptiles.
- He notes the impact's timing and location mattered so mammals could later diversify into dominant roles.
Impact Location Changed Evolutionary Fate
- The asteroid's effects depended on where it hit and the local rock chemistry that amplified atmospheric consequences.
- Carroll says only 1–13% of Earth's surface had that rock mix, so a different impact location could have left dinosaurs dominant.
