askscience

Title	Upvotes	Mark as read	Favorited	Rating	Add to a list
When in human history did we start cutting our hair?	14562
This is not a 'cicada year,' but I hear one buzzing outside right now. Is there a small set of cicadas out of sync with the main population, or do a few mistakenly mature early every year? Or is this a different species entirely?	5487
Do volcanic islands preserve fossils in the same way as sedimentary rocks? If not, how do paleontologists reconstruct the evolutionary history of organisms on volcanic islands?	3281
When birds fly south for the winter, how exactly does the population Distribution change? Do they all fly south an equal distance and displace each other, or do those that spend summer farther north have to fly farther south to find unoccupied territory?	3076
Can dogs tell the difference between male and female humans, either by sight or smell? If so, do they behave differently towards men and women?	735
Is there an "uncanny valley" for sound like there is for sight? Does the sound of very nearly replicated voices, or oddly filtered voices, elicit the same sense of revulsion as does the sight of very nearly-human robots?	522
Do accreting binary stars have a habitable zone?	447
We're often told that skin pigmentation evolved with latitude (ie, pale skin in Europe, dark skin in Africa) due to the intensity of the sun and for vitamin D synthesis. Can the same trend with skin tone and latitude be seen genetically in Native Americans?	371
Tornadoes, hurricanes, and monsoons only occur in very specific regions on earth where the conditions are right. Was there a "Tornado alley" in Pangaea? Did the coasts of any ancient continents have monsoons and hurricanes?	100
Birds have maternal instincts (i.e. they care for their young), but many reptiles don't (for example, turtles abandon their eggs). What about their common ancestor? What about dinosaurs?	9

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