I never learned much about evolution, so please do explain it like I’m 5
In: Biology
They didn’t go extinct completely; the ones that remained evolved into, or were already, birds.
Imagine you are playing a very long and very complex roguelike game.
The game has millions of levels, and each time you survive a level you get to choose a tiny upgrade to your character. Actually, no, you don’t get to *choose.* You see a few options but the game randomly chooses for you, and you just have to do your best with what you’re given.
The upgrades aren’t new, flashy things. In fact, they almost always build on something you already have. And the upgrades are TINY. So tiny that you usually can’t immediately tell what’s the point of even having them. Your thumbs are 1% longer. Your hair grows 1% faster. You can walk in the cold for 1 minute longer before being bothered by it. But who cares? So long as the upgrades aren’t causing you any actual *trouble*, you’ll be fine playing as you’ve been. Sometimes the upgrades even make your life slightly easier or help you survive a close-call.
Until, that is, the level design suddenly changes. You’ve been playing forest levels for the past 100 000 levels, and now suddenly every other level is a frozen wasteland. Whatever strategies you’ve developed are about to get seriously tested, and you hope you can adapt to this new ice meta before you game over. And you see people getting a game over around you all the time, this sudden change isn’t just tripping you up, it’s a challenge for everyone.
Suddenly, being able to survive that 1 extra minute in the cold is a huge advantage. Your friend who was thriving in the forest levels with his tree-climbing skills? Dead. Couldn’t handle the cold. Your other friend who got all the upgrades for finding fruit? Gone. No fruit in ice levels.
Meanwhile, you got lucky. You had that cold survival upgrade that saved you from instantly getting deleted in the ice levels. And now, you’re lucky because you keep rolling more cold upgrades. It makes sense. The game builds on skills you already have, and you already had that one cold upgrade. Now you have three. Five. Ten. Ten thousand. The more cold upgrades you have, the easier it is to get more of them. This ice meta is great! You feel right at home.
Until, of course, the meta changes again. And suddenly, you and your cold resistance build get plunged into a desert. You can survive one level like that. Can you survive a hundred thousand? Your skills are useless. Many are actually a detriment. You start feeling like your fruit-eating friend who couldn’t handle the ice meta. You start worrying you can’t handle the desert meta. And you’re right. You can’t. Game over.
If you were to play again, what are the chances you would end up with the same exact build? Essentially zero. The skill upgrades are mostly random, so you might never get a chance to get the same upgrades at all. The levels, as far as you can see, are also random. There might be some logic to them, but you can’t figure it out. In any case, that progression you’ve seen, forest to ice to desert, probably won’t repeat for you the same way.
Or, in evolution words:
Evolution does not consciously work towards a goal. Environmental conditions select for which random mutations are more likely to survive. You will never get the same exact environmental conditions or the same exact mutations to repeat, so you won’t get the same exact thing evolving twice. You might get pretty darn close though, if the conditions are similar enough and you get a little lucky (convergent evolution).
Partially because the conditions under which dinosaurs evolved in the first place no longer existed. The weather, plant and animal life, even the oxygen content of the atmosphere changed over the last 65 million years.
When dinosaurs evolved, there wasn’t much competition for food and space on land, so they filled the ecological niches and took up a lot of the resources. So, when most dinosaurs went extinct, they left a large gap in the ecosystem and other animals, particularly mammals, quickly filled that niche. Suddenly there was a lot of competition for food and resources, and so it was a completely different world than the one where dinosaurs first evolved.
But remember, not all dinosaurs went extinct. Some had evolved into birds about 150 mil years ago and those thrived in the new post-extinction world. Ancestors of dinosaurs are still pooping on your car, even today.
Evolution has no goal/objective. It just keeps on happening all the time (even right now!!).
The conditions prior to the dinosaurs were completely different 65 million years ago.
It could maybe go in the “same” direction again if everything restarted, (and i mean everything), but thats a major stretch. And Alot of animals, insects and bacteria survived. so it wasnt a clean start. the Mammals that survived got a major head start.
When the dinosaurs were around home much gamestop stock did they own?
No two consecutive minutes are equal. It’s easy to understand that many non equal minutes, turned into non equal weeks, months, years, centuries, millenia will not repeat the same exact changes.
Also, there’s a minor misconception in your question. We have dinosaurs today. We call them birds.
I’m going to let Dr. Ian Malcolm answer the question for you:
Dinosaurs had their shot and nature selected them for extinction.
Nature does not demand the dinosaur, once they were gone there’s nothing saying you need to evolve into a dinosaur to replace then in their niche.
Unlike crabs, which have evolved several times from different sources…
Evolution is based on life’s interaction and adaptation to the environment. The environment was not the same.
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