Mother's Day marks the halfway point of Lent, and one theory of its origin is that it was marked by visiting the region's "mother church" or cathedral.

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Another theory of the origin of modern humans, known as the multiregional hypothesis, holds that earlier forms of humans originated in Africa and then slowly developed their anatomically modern form in every area of the Old World.

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He landed, camped there, left and returned, studied, researched and conceived his earth-shaking theory of evolution, On the Origin of Species, in 1859.

FORBES: Connect

These findings would not have surprised Charles Darwin, who in addition to theorizing on evolution in The Origin of the Species, also developed the Facial Feedback Response Theory, which suggests that the act of smiling actually makes us feel better (rather than smiling being merely a result of feeling good).

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That suggests another theory is needed, in which the state plays a bigger role in the origin of money.

ECONOMIST: Free exchange