A large number of species have died out, their disappearance we know has been down to human beings. The moa, dodo, so many others. But would the very landscape be different? What effects have building mega-cities occasioned? Would the survival of neanderthals have made a difference?
I believe that it would still be predator and prey dynamics and the most equipped species will survive.
Rich
Maybe something like this would've evolved instead:
https://img-9gag-fun.9cache.com/photo/aprg8w8_700b.jpg
I wonder why, Karl, they never have genitals?
Richard, will some we now know become giants? Some archaeologists believe that humankind stopped the ice ages by building fires, so would the ice have continued to expand?
Would cave bears still inhabit Europe?
Stanley Wilkin
They could be in the mouth. I seem to recall a story in an old Astounding Stories or somesuch SF magazine where what the aliens had under the veil was much sought after by spacefarers on "shore" leave. In principle the ingestion end could serve a dual fuction (ha ha, I'll leave that possibly Freudian typo) just as well as the excretory end.
Stanley Wilkin
Addendum re "they could be in the mouth".
Apparently evolution has already taken Phallostethus cuulong partway there:
«The more technical name for the male fish's penis is the priapium, a complex, muscular organ that looks like it's attached to the fish's chin. The priapium includes the urogential opening and the anus, as well as a bony rod and a sawlike hook, used to clutch on to the female during mating, the researchers said. The female fish's genital opening is also located at her throat.»
— https://www.livescience.com/22824-penis-head-fish-discovered.html
Karl, a much more serious notion than might be realised. The evolution we know, or think we know, based on similar sexual activity and procreation seems limited to the larger species.
Apparently, sex occurred first millions of years ago and then promptly ceased, to be restarted millions of years later. But our removal would not then involve alternative kinds of evolution but changes in those that continued or those that perished consequent to our development.
What it could mean is that other human species, which we now know existed alongside us, might have pushed forward and claimed our territory.
Evolution does not have a fixed end goal but rather a continuous process for survival.
How the first life originated is still a matter of question. However, if the so-called human species today had not evolved, then other more robust species would have dominated Earth (let it be other life forms, different stages of human evolution).
And I agree the scene would look like what Richard Kensinger describes above.
What we also need to look at are the questions:
What if our species stops evolving and mutating. How do we survive the extinction of planet Earth when our Sun (a star) grows to a gas giant.
I hope we can survive and even thrive on being a space-faring species.
Raksha,
The possibility of human beings travelling a short distance into space seems close to reality, still, us surviving until the sun expands seems mercifully unlikely. We have survived a relatively short period of time, not long enough for us to witness a serious event such as catastrophic climate change or being clobbered by a large meteorite. But Neanderthals disappeared because of a low birthrate, perhaps we will because of one too high.
All organic species exhibit the following functions: find energy, consume it, procreate the next generation.
Rich
Yes, Richard. I wonder why. And who do we go the extra yard.
The overall meaningless of life is maybe what makes us invent religion?
Stanley Wilkin
You wrote: "What it could mean is that other human species, which we now know existed alongside us, might have pushed forward and claimed our territory."
For sure. But when you postulate "if our species had not evolved" it leaves unspecified how far down the evolutionary tree our evolution might've been cut off and by what means. Potentially no post-pre-or-proto-humans. In which case big-brained upright bipedal prehensile-handed saurians or insects might've come to occupy our niche. Or even descendants of Rattus norwegicus 🐀 😍.
I was impressed with the software-CD that once upon a time came with Dawkins's The Blind Watchmaker, which showed how quickly something complex could evolve from almost nothing.
https://blind-watchmaker.soft112.com
Karl, that is true. I have seen nature programmes that show how another, often smaller species, can occupy a vacant niche.
Aref, not at all. Neanderthal and Denosivic both appeared to have changed over time, as did we. But another human species might have come through from elsewhere. Neanderthal's communities seem to have been very small, insufficient for human expansion and invention.