To be accurate, even by the most restricted commonly used definition, the birds evolved several million years before the rest of the dinosaurs went extinct.
Yes, but avian dinos survived quite well, and are not all known for their ability to burrow, swim, or dive. Avian dinos are about the same size and are quite similar to the smaller feathered warm-blooded dinos.
Altho it is doubtful that any did survive for any significant period, there is no reason what they could not have. Birds did.
Dinos were around for about 165 million years and never evolved into anything like us. Large mammals have been around for only 65 million and one group evolved into us. From this I infer that evolution of anything like us is not certain and maybe improbable. You cannot do statistics with only one datum.
I have read that dinos were in serious decline even before the K-T boundary. That doesn’t mean they would have gone extinct, but they might have. I guess the climate was changing.
Intelligent technological dinosaurs…either of two things (not necessarily mutually exclusive) would have to be true there:
(A) They could have, but didn’t (chance and contingency preventing it)
(B) There was some constraint(s) inherent in the physiology or genetics or such of the entire clade that prevented it
I recall seeing some indications of (B) somewhere (a Sci Am article from the previous decade?).
Cockroaches have been around for hundreds of millions of years, and have stayed almost identical for that entire time. They’ve also continued evolving for all of that time. Evolution does not necessarily mean change.
A refresher on how evolution works: You have some creature (say, a finch). The finches have many offspring, and most of them are basically just like any other finch, but occasionally, one is born that’s different in some way. Most of the time, the different finch is less fit for its environment, and has fewer offspring, and that line dies out, but sometimes, the different finch is more fit, and has more offspring, and its line grows. But either way, it’s evolution.
And it works that way with cockroaches, too. It’s just that cockroaches are already so fit that essentially all of the roaches that are a little bit different are less fit. And so evolution is keeping the roaches fit.
“Carry on, my saurischians,
You’ll be birds when you are done.
Feathery and egg-laying
And not toothy no more!”
Huh? No change, no evolution.
Do you mean “Evolution does not necessarily mean change that is obvious to the naked eye?”
A few points:
Evolution most certainly does mean change. It’s the basic definition of the word.
Cockroaches only *look *the same as they did 100 MYA. Internally they have changed a lot. The composition of the atmosphere has changed. Food sources have changed. Cockroaches had to adapt. A roach from the Carboniferous would not thrive today, nor vice versa.
It is not correct that most mutations render a finch “less fit.” Changes usually are not tested immediately. A mutation may for instance give a slightly different beak shape. It can spread though the population of finches. It becomes a part of the natural variation in the species, some individuals have it, and some don’t, and neither has a noticeable survival advantage. And then an environmental change a million years later gives one group an advantage. Survival of the fittest tests ancient mutations, not modern ones.
Well, most mutations have no effect whatsoever, because they’re in a non-coding section of DNA, or change a codon for some amino acid into another codon for the same amino acid. But if a mutation does anything at all, it often results in a nonviable organism, which is certainly a decrease in fitness.
And without natural selection, cockroaches would have diversified vastly over the hundreds of millions of years they’ve been around, just from genetic drift. The fact that they haven’t is because natural selection has been at work culling out the drifts.
Well, cockroaches are a lot more diverse than the “german” variety most people think of. Plus, there are the related praying mantises and termites.
So, just to be clear, are you doubling down on the statement that “evolution does not necessarily mean change”? Or, are you saying it was a mistake to say that?
So I’m assuming the ability to fly proved a great advantage. There may have been others factors, I’m no expert.
I’m wondering if the fact that we evolved from tree dwelling species played a crucial role in how we developed. Our ancestors had to have nimble hands and fingers to live in trees and also stereoscopic vision in order to judge distances when jumping and being able to take care of young in a difficult environment. Also a quick brain which was presumably was an advantage in such an environment. Of course, mutations must have played a part too, so whether dinos would have evolved along the same lines is difficult to say.
And this is how we know it is a season finale of Suchusnatural.