When I go backpacking I go to bed with the sun and wake with the sun. That means 6pm bed time in the fall and getting up around 7am. I do tend to wake up in the middle of those long nights and find it hard to go back to sleep. I don't think we necessarily need more sleep, but I do think by nature we are designed to sleep when it's dark. Nearer the equator the nights wouldn't vary so many hours throughout the year.
Female, 5'3", 49, Starting weight: 163lbs. Current weight: 135 (more or less).
Starting squat: 45lbs. Current squat: 157.5 x 2