Could humanity survive the same asteroid that killed the dinosaurs?
Yes. Many people would die in the first few years after the impact, but after 100 years the human population would be in the millions, possibly in the hundreds or thousands of million, and growing.Depending on where it hit, initial deaths would be in the range of a few thousand (for a deep water ocean strike) to a billion (hitting around Nepal).The debris ejected by the impact would wreck agriculture for between 5 and 60 years. Most deaths would be due to either starvation, or war between groups fighting for food/areas that could grow food.
If the asteroid that wiped out dinosaurs hit earth again, would humans survive and, if not, how much time after the blast would they become extinct?
We don’t really know, because we don’t really know the exact dynamics of the last one. Very large impacts can cause the entire planetary atmosphere to glow for hours in the infrared. If that were to happen, every living thing above ground on the surface would die, world wide, within hours. Some humans would survive, but would likely be unable to produce any food for many years after the event. Coastal fisheries would also collapse, so any survivors would be unable to merely move to the coast and live off seafood.Nevertheless, it’s not impossible that small groups of humans would find the means to survive, dig out some seed from protected stocks, and eventually start anew. Anything’s possible, when you have opposable thumbs and libraries.
When dinosaurs were wiped out by the asteroid, how did alligators survive? Did they then evolve from a common ancestor that survived the event?
It’s a common mistake to imagine that the K-Pg mass extinction wiped out all the dinosaurs (and pterosaurs, and mosasaurs, etc.) and left everyone else unscathed.But that’s not true.Almost all groups of life suffered during the K-Pg mass extinction. Some groups did pretty well (ex. Many amphibians, marine scavengers, fungi, and more), some suffered significant or near-total losses (ex. mammals, birds, most groups of reptiles, corals, and more), and some were wiped out completely (pterosaurs, all non-bird dinosaur groups, ammonites, and more).Crocodilians, including gators, fall under the “significant losses” group. They weren’t wiped out, but they weren’t unscathed either. Alligators (or at least the alligator lineage) already existed in the Late Cretaceous (some were huge!), and at least some survived to give rise to 65 million years of more alligators.As for the question of why some groups survived and others didn’t … this is one of those questions that everyone wants a nice easy answer to, but not only do we not have a nice easy answer, there likely isn’t one. A lot factors into how hard a species might be hit by a mass extinction: their biology, their geographic location, their recent history leading up to the extinction, and – perhaps the most underestimated factor – luck.It might be that alligators had something special that allowed them to out-survive the likes of tyrannosaurs, pterosaurs, and ammonites. It might be that this special something (or part of it) was something they shared with mammals, birds, dragonflies, sharks, and all the other groups that survived the K-Pg. And it might be that gators – at least partially – got lucky.Read (and hear) more about the K-Pg mass extinction!
Why did the asteroid only kill the dinosaurs?
In the circumstances following an impact, great size was actually a serious disadvantage. Dinosaurs were among the most vulnerable creatures because, being dominant and large, their populations were relatively small, hence vulnerable to a disaster. Also, it was hard for big creatures to find shelter from impact debris. Lastly, as energy intensive creatures, dinosaurs had great food requirements, which made them particularly vulnerable to the effects of energy depletion following obscuration of the sun by impact dust/smoke. But MANY other creatures perished with them--plankton, mosasaurs, ammonites, belemites, pterosaurs (which like dinos had grown large and energy intensive toward the end e.g. Quetzalcoatlus) some birds etc. Cats, dogs and squirrels hadn't yet appeared by the K-Pg. It is noteworthy, though, that dyrosaurids and most other crocodiliformes survived the impact, despite their large size. They were ectothermic and probably survived because of low food requirements (and availability of carrion); obviously proximity to water didn't ensure survival, given the very high mortality suffered by marine creatures.
How did the human beings survived from the impact of the asteroid hitting which killed all the dinosaurs?
Here is your “Great to the nth Grandaddy” at the time the asteroid that killed the dinosaurs arrived.Skinny 'Shrew' Is Oldest True MammalKinda cute, ain’t he?Most likely he survived by being very small, not needing a lot of food, and hiding or hibernating in deep burrows during the worst of the disaster that wiped out all the large sauropods.
If an asteroid, like that which killed the dinosaurs, hit earth, would mankind be able to survive the aftermath?
As a species, meaning we could keep enough of us alive to ensure a viable breeding population to be able to re-populate, yes. What would that “viable breeding population” be like? Less than 50,000 individuals. Currently we’re over 7-billion. Dinosaurs didn’t have protective structures. They had reigned over the earth for so long that they were often hyper-specialized in their environments and diet. We can live almost anywhere and eat almost anything. We’re the vertebrate equivalent of cockroaches, so yes, kill off 99.99995%, and we could still bounce back. Of course, the earlier evolutionary bottleneck humans survived (genetics show that our population might have been as small as 10,000 at some point during the ice ages) was when we were geographically close so we’ll have to huddle somewhere and wait for the environmental hellstorm to stop to stop falling.The K-T extinction was not an example of a planet becoming un-inhabitable. Just a planet’s ecosystem losing so much of it’s food chain that anything with a body weight of more than about 15kg simply starved to death or froze.Yes, humanity can live through that.But the outcome won’t resemble anything you’d recognize, since our cultural identity and technological infrastructure would definitely go extinct.
How did mammals survive the asteroid impact that killed off the dinosaurs?
Animals no bigger than the size of around 1 meter survived because they could easily adapt to the changed ecosystem. Burrowing creatures would've had a good chance as they may have ate small roots.