Darwin orchid long nectar tube Xanthopan moth

A long orchid tube led Darwin to predict a long-tongued moth

A Madagascar orchid has an unusually long nectar tube. Charles Darwin predicted a moth with a tongue long enough to reach the nectar and pollinate the flower. Explorers discovered the moth, Xanthopan, in 1903.

Dark roast can contain less caffeine per scoop than light roast

Roasting causes coffee beans to lose moisture and expand, changing their density. Dark-roasted beans generally take up more space for the same mass, so a scoop measured by volume may contain less coffee and therefore less caffeine. If you measure equal weights instead, the caffeine difference is usually much smaller. How you measure matters more than roast color alone.

China often tests new policies in one place first

China often tries a new policy in a local area before using it more widely. This lets the national government keep strong political control while giving local governments a large role in running the economy.

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Darwin orchid long nectar tube Xanthopan moth

A long orchid tube led Darwin to predict a long-tongued moth

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