Question

why are some of our body parts in pair​

Answer 1

Evolutionary anthropologists guess that we have two limbs, two lungs and two kidneys because these dual organs gave our ancestral organisms some kind of advantage, not because they're spare parts We can see with one eye (and one-eyed organisms evolved first), but two eyes offer the advantage of depth perception.

Answer 2

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Evolutionary anthropologists guess that we have two limbs, two lungs and two kidneys because these dual organs gave our ancestral organisms some kind of advantage, not because they're spare parts We can see with one eye (and one-eyed organisms evolved first), but two eyes offer the advantage of depth perception.