Some questions on evolution.

must there be a point in time where there was a species with no _____, such that they died out and only those that evolved them survived? feel free to fill in the blank with anything that would affect survival: like pain receptors, unconscious breathing, ability to store fat, whatever.

what are the earliest evolutions of humans? the ability to stand and walk upright? what are the last? what are the earliest living things with a face? (i.e. with two eyes, a nose and a mouth)

wondering out loud.

There are plenty of extinct species, some of which have living descendents, and in every single case those descendants have some trait or another (even if only an apparently trivial one) that their extinct ancestor lacked. Though this does not necessarily imply that the lack of that trait is why the ancestors died out, or that its presence is why their descendants survived: Far more often, it’s just a matter of dumb luck. And even if the new trait was what made the difference, it’d be really hard for us to know that.

For your second question, about humans, it all depends on what you’re counting as “human”. Most things humans can do, all of the simians can do, just not as well as we can.

A good example might be feathers. There is plenty of theory that dinosaurs developed the first feathers, but all of them are definitely extinct, as well as the earliest forms of modern birds.

The kind of change you are referring to is really big and probably would not happen abruptly. For example, I really doubt that some species developed the ability to store fat in one step. Usually these changes occur in many small steps which will, at some point, result in a selective advantage or disadvantage to the owner of the new trait.


Well that would be a new species evolved from chickens I think, so it’s not really a dinosaur. I know people like to call birds dinosaurs, but by that convention mammals are hairy fish. Anyway, it was a simple example to use for the OP.

It’s hard to tell when an animal with no hard parts appeared because tiny bits of snot rarely fossilize, but larger animals with proper faces (mouth and sensory organs at one end, anus at the other) date from a half-billion years ago.

Strictly speaking this is tautological; by definition they aren’t the “same” species anymore, thus must necessarily have at least one trait which sets them apart from their ancestors.

He, and you, may be answering the OP. The language is a little stilted, but my original reading may be off too. Thought he was asking about a modern animal that has a feature that an extinct ancestor had. However, on rereading he may just be asking if there is a species that survived when it’s ancestor didn’t, and that describes most modern animals.

Right, which means that the question to which that is the answer isn’t a very interesting one. I’m hoping that the OP will come back to clarify the question.

Just because Windows 8 is released doesn’t mean my Windows 7 machine stops running. Same deal with fat storage.

Depends on what you want to call a human. The human and the chimp* lines split about 6M years ago, so everything on that line is not-chimp. But there were lots of branches and dead ends. Scientifically speaking, we define “human” as either anything in the genus Homo or, more narrowly, only the genus H. sapiens. Our genus is about 2M years old and our species is about 200K years old.

Upright walking evolved long before our genus did. At least twice as far back, and probably farther. I would not call any of those early upright walkers “human”. They would be much more like an upright chimp than a human.

*our closest relative

What gets me about evolution is why if dinosaurs were on this planet for about 200 million years, why didnt any of them evolve into an intelligent species? Humans from what I can tell, have only been around for about 1 million yeas and homo-sapiens about 100,000.

For that matter why are humans the only intelligent species? Why dont we see intelligent fish or birds?

Last? We ain’t there yet. H sapiens sapiens is still evolving, and some scientists think we are evolving a faster rate than ever. Next stop giant crania with throbbing veins!

There is evidence that some species of raptors hunted in packs. This requires at least a dog level of intelligence. It happens that testing for intelligence on long dead species is rather difficult, so definitive answers are few.

Intelligence is not a goal of evolution, evolution has no goal other than survival. Human intelligence has some distinct disadvantages. Our brain case is so large that human birth is actually dangerous for the Mother, for example.


Not sure why you’d post erroneous dates exactly below where I posted the accurate ones.

But “dinosaur” is a very large group of animals, and isn’t in any way comparable to a single species or even a genus. And there were certainly some dinos that were more intelligent than others. Just as there are some mammals that are more intelligent than others.

There are plenty of intelligent birds, like parrots and crows/ravens. What you seem to be asking is why no other animal is intelligent in the same way as humans. The answer to that is the same reason we’re not intelligent in the same way as cetaceans or elephants.

Also, keep in mind that “humans” came in several different varieties as recently as 30-50K years ago. At that time, you would find us, Neanderthals, H. floresiensis, and maybe even remnant populations of H. erectus. All of these would be intelligent in ways very similar to us.

Indeed. The jury is still out on how great it is to be intelligent in the human sense. If we’re all gone 100,000 years from now, a lot of other species are going to look a lot more successful.

And let’s not forget that, Tripolar’s point notwithstanding, dinosaurs did evolve into intelligent animals-- birds. Many birds are surprisingly intelligent.

There’s nothing special about intelligence. You might as well ask why they didn’t all grow as large as a blue whale, or all develop wings and flight, or all become poisonous. Intelligence, like all those other traits, is just one survival strategy among a huge number of other strategies.

Self-awareness then.