This week’s new questions

What is an itch, and why are most so easily calmed with a simple touch? And if my family tree doubles at every past ancestor generation, at what point does it decrease to reflect the size of the population?

1 July 2026

Man used the wooden back scratcher for his back itch therapy in small trees background closeup.; Shutterstock ID 2142811281; purchase_order: -; job: -; client: -; other: — Shutterstock/Soraya Plaithong

What is an itch, and why are most so easily calmed with a simple touch?

Tony Burton
Glasgow, UK

B6CK6J Family Tree painted on a rock at Nambucca Heads NSW Australia — Wiskerke/Alamy

My family tree doubles at every past ancestor generation, branching back into the past. At what point does it decrease to reflect the size of the smaller historical population?

Paul Clark
Battle, East Sussex, UK

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