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Does a fast heartbeat use up a lifetime's supply?

A mouse's heart and an elephant's heart run at very different rates, and their lifespans differ too. Multiplying heart rate by lifespan produces an intriguing cross-species comparison, but the result depends on which rate, lifespan, and animals were measured. An approximate pattern is a long way from a personal countdown.

3–5 min

Questions you could explore

  • What would have to be true before a correlation became evidence of a fixed lifetime quota?
  • How could comparing species differ from testing a fixed-heartbeat claim within one species?

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