Electroscope and fitness tracker: what they have in common

1. Step 1. Electroscope — is made of — Gold. With leaves of gold leaf.
2. Step 2. Gold — is material for — Wristwatch. The case is gold or silver.
3. Step 3. Wristwatch — evolved into — Smartwatch. The form factor of a wristwatch.
4. Step 4. Smartwatch — evolved from — Fitness tracker. Tracker functions moved into watches.

Open Evothings