Why didn’t the asteroid that caused the extinction of the dinosaurs on Earth also lead to the extinction of all other living species?
In: Planetary Science
They were smaller species that could survive the impact or live underwater which later evolved into bigger species.
Asteroid struck earth but it didn’t blow it up. Same way how cockroaches and other smaller animals or insects would be able to survive nuclear holocaust.
The many effects of the impact caused the extinction of most large animals. The smaller animals and plants survived and then thrived in the ecosystems which now had space for them to grow and evolve.
This is a good example of the importance of biodiversity. The broader the array of species, and the habitats that sustain them, the higher the probability that some will survive a catastrophe.
Because the asteroid didn’t obliterate the earth, it just destabilized the climate and ecosystems that supported the dinosaurs to such an extent that they couldn’t survive. It took a massive amount of vegetation to keep the leaf eaters alive, and a massive amount of those to keep the sharptooths alive. As cold blooded animals, they also had to deal with intentionally regulating their body temperature, something a massive asteroid would have made more difficult.
Mammals and other small creatures on the other hand did not face these same challenges to the same extent as the mega lizards did. They could survive on smaller portions of food, in more diverse areas, etc.
Dinosaurs are not really considered to be extinct, they evolved into what we know as birds today.
Well it did…. that mass extinction event eliminated 96% of ALL species, dinosaur, mammal, etc. But it didnt eliminate all of any group of species. It didnt even eliminate dinosaurs. All birds are dinosaurs. A similar fraction of mammal species survived, and managed to grow into the gap that was left by the now vanished species.
‘Why evolution is true’ goes into great detail about this – it’s quite interesting and basically species that burrowed for example had a higher chance of survivability (also aquatic species) – there are some good arguments suggesting that without this event humans would not have evolved.
Edit: it may have been ‘A series of fortunate events’ by Sean B Carroll actually..both great reads.
Because it didn’t just create one huge planet wide explosion that killed everything instantly. It was a huge impact and it vaporised a huge area but the real impact so to speak was the drastic change in the climate that it caused, which most animals at the time could not survive through, but that didn’t mean no life could survive. Plants, sea creatures, insects, many of them persevered.
Because species like mammals were able to burrow better, shelter from the elements and find food. Much of the plant life died, causing a chain reaction with herbivore dinosaurs and then carnivores.
It also explains why water species like alligators and sharks are still around.
Large animals in general have a harder time adapting to changes. They need a lot more resources to survive, don’t breed as frequently as smaller animals, and start out with a smaller population. If 95% of your food source dies and you’re an elephant, your population quickly eats the remaining 5% and dies. If you’re a mouse and 95% of your food source dies, the scrappiest/luckiest of you can still survive on that 5%. Even if 98% of you die, your population is still big enough to breed and survive.
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