They did in a few cultures. But most cultures were not consuming rice and bread 10.000 years ago.

The ones that did have sugary diets many thousands of years ago, like the egyptians, also happen to be the ones who practiced early forms of dental care.

If all you eat is apples, sure. But you're probably having things like crackers, rice, sugary tea or coffee, eating bread, etc.

They didn't, and they didn't really need to.

You can still see it in tribal populations today. They don't care for their teeth at all, yet they've got perfect teeth, better than ours.

That's because their diet is very low on refined sugars, and composed mostly of fruits, vegetables and fish, with some occasional red meat.

It also reflects on their skin. They have smooth lively skin free of acne, despite not using any skin care products. That's also due to lower presence of sugars in their diet, and also because their culture doesn't drink alcohol.

If it’s safe to have it injected it in you, it’s safe to be around someone who will cough out maybe 0.001% of what they had injected into them. Especially with such a short half life

Lots of fruits are intended to attract animals to eat them, not just avocados or large fruits.

Seeds do not need to be large to survive the gut, for example if you eat corn kernels they will easily survive your gut.

And the spreader animal does not need to eat the fruit whole to ingest seeds, it can just take bites out of the fruit and then ingest some seeds whole incidentally.

A pig or a cow, for example, will eat a pumpkin. Not whole, of course. But in the process they will end up ingesting whole seeds, that will survive their digestive tract and be spread around.

Yes that is what it is called when animals clean themselves or their fellows out

Because it’s the difference in hormone levels compared to baseline that causes a high. While your first testosterone injection might cause a high, you will quickly get used to it.

Serotonin and dopamine are not just simply hormones that when released make you feel happiness. That’s a gross oversimplification.

There are a lot of ways to “cheat in happiness”, see any recreational drug.

It depends on who you’re asking. Some people believe we should purposefully colonize other planets with life, in the hopes that someday some of it will thrive. For scientists, it is very bad, since it will make experiments that check for the remnants/presence/building blocks of life possibly return false positives. In the grand scheme of things, taking humans to mars is impossible without contamination of the red planet, and the scientific value of having a human on-site on mars likely outweighs the negatives of contamination.

Since you mention comfort, I would like to add that while this isn’t related to the perception of temperature, extremely dry and hot environments can feel more uncomfortable than humid and hot ones.

Because the dry hot air dehydrates you very quickly, especially your throat and nose get dry in a matter of minutes, it feels very uncomfortable and is (in my own opinion) worse than a hot humid climate.

Partially filled would already make your soda at least partially flat, since for your soda to be fizzy the liquid needs to be saturated with carbon dioxide, and having air in the container would make the liquid lose its carbon dioxide to that air.

You could have a high pressure carbon dioxide atmosphere inside your half-filled can, but then you come into a multitude of problems, like the fact that upon opening it would instantly explode like a shaken can of soda, and there would be very little liquid remaining for anyone to drink.

It’s also not just fatalities that matter, it reduces the risk of serious injury too. I’d rather hit an airbag and break an arm than hit the steering wheel or glovebox and break 9 different bones and have my face smashed in, even if I don’t die in either situation.