Most species are transient. They become extinct, differentiate into new species, or change due to random or environmental mutations. The "modern" human species (how to say? Homo sapiens) has been around for more or less 300.000 years. What will happen if we get to a million years?
One of the first to ask this question was the science fiction author HG Wells: in his short essay of 1883 called "man in the million year" he prefigured the next evolution of the human species. Today that prediction of him has almost become a common opinion: the human species will have a large head and a small body. Or it will split into two or more new species.
His hypotheses, although in detail not in conformity with the discoveries made to date, are still generally valid.
More than a human species, or a more than human species?
Future (but predictable) technologies such as the strengthening human, uploading cerebral or artificial intelligence (AI) they could produce technological forms of new human and animal species that do not yet exist today.
It is impossible to predict the future perfectly. Those who design scenarios for passion or profession analyze current signals in perspective, but there are also some elusive unknowns. If we explore the possibilities, however, the most likely case seems to be that of a vast "speciation": it is plausible that the human species will also split into several others.
Who among us wants to improve the human condition (slowing down or stopping aging, improving intelligence and mood, enhancing the body) could create a 'strand' leading to new species.
It is clear that there are also people who reject things of this kind on principle, and also by virtue of this this separation will take place, which we could define as of another kind.
How to define them? "Humans" and "Post-Humans"?

From one kingdom to another
I mentioned a frontier technology: that of brain scan to transfer consciousness to another medium, or send it online to a cloud.
If we could achieve it (having a huge time ahead and without dying out for other causes) we could even go beyond speciation, passing from the animal kingdom to the "mineral" one.
There are many reasons why someone might want to do this: to increase the chances of immortality, to acquire incredible computational abilities, to evolve in new ways.
Unlikely, however, that humanity will remain the only intelligent species on the planet. Artificial intelligence is advancing rapidly, and many experts think it could become sentient this century, or sooner (some even think it already is).
It can happen, and it probably will. We may find ourselves on a planet where the human species as we know it today will have been largely replaced by artificial forms of intelligence, or a mix between hybrid and artificial.

Human and post-human species: Utopia or dystopia?
If we make an effort to reason in a non-ideological and non-sentimental way (that is, in a way that I don't like, but which can be functional) it seems plausible that some part of minds will eventually turn into software.
Computers could become much more efficient than human beings: they would not need to eat, drink or sleep ('inefficient' ways of feeding themselves) and could save energy simply by 'slowing down' their functioning at will. In short, in the distant future, with the same energy and matter, artificial minds would be much more sustainable than biological ones.

There are quite a few differences
Physical beings have a distinct disadvantage compared to future, possibly "artificial" beings: they move in the slow world of matter. But they also have a great advantage: they are self-sufficient: they do not vanish if their connection is interrupted.
Again: "natural" humans can remain in traditional societies that are very different from those of "software people". In the future there could also be a form of peaceful coexistence: "flesh and blood" humans would be a bit like today's Amish communities, they would live by their rules tolerated by the new "technological" species.
Will it really be like this? Impossible to say with certainty: especially on such dilated timescales.

A vision of the world in 1 million years
There is still a human species, and it more or less resembles us, but it is less numerous than the current one. Much of the planet has gone "wild" again, because much less land is needed for agriculture and cities: what we now call "rewilding" has taken off.
Here and there cultural sites with very different ecosystems crop up, carefully preserved as party favors by robots for historical or aesthetic reasons.
Beneath an ocean of solar arrays in the middle of the Sahara desert are trillions and trillions of artificial "minds," inhabiting massive data centers that once threatened to overheat the planet.
It wouldn't be a good or bad world. Not from our perspective, I mean. We cannot judge it.
However, in a million years from now) the least unlikely option is that the "biological" human species will have died out long ago.
If that's the case, however, the most likely reason will be a lack of respect, tolerance and clear rules with other post-human species.
Let's start being kind to each other and also to the machines: you never know.