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Why are birds mostly monogamous, but not mammals?

Birds are mostly monogamous because it is the only way that males can be sure of having any surviving offspring.

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This week’s new questions

A man holds his lurcher dog as the canine excitedly licks and nuzzles with a woman who smiles and strokes the pet.

Is sweat from exercise different from that due to anxiety or illness?

2J7J6G8 Berlin, Germany, May 09, 2022, German Chancellor Olaf Scholz and French President Emmanuel Macron attend a joint press conference at the chancellery in Berlin, Germany, May 09, 2022. This is Macrons first official visit after his re-election. The two leaders will discuss bilateral matters and Russia's ongoing war in Ukraine.(Photo by Omer Messinger)

Why do speakers at public events wave their hands around so much?

EX0YM9 Stirring tomato sauce and black pepper in a glass bowl with spoon

This week’s new questions

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How could I theoretically reach other dimensions in the multiverse?

Why does my water freeze in this pattern like dandelion fluff?

Humans have “good bacteria”, but what about “good viruses”? (Part 2)

This week’s new questions

HBATA9 Portrait of identical adult male twins with red hair and beards on sidewalk

Is there a way to show which identical twin is the father of a child?

It wouldn’t be easy to determine which of identical twin brothers was the father of a particular child, but there are ways

Are crops more nutritious when grown outside in direct sunlight?

If “the house always wins” how do professional gamblers cash in? Part2

This week’s new questions

Why is this snail carrying an extra shell on its back?