A problem regarding Humanities reclamation

As Cryptum established, multiple humans species created a prehistoric, space-fairing civilization which once challenged the Forerunners. They pulled off many amazing feats like create numerous colonies, found an alliance with ancient San 'Shyuum, and constructed a “cure” for the Flood (though what the Primordial has said makes me doubt its legitimacy).

They managed to stave off the Flood, but ultimately lost when fighting the Forerunner. Their civilization was then regressed by the Forerunners. However because their “cure” was lost, Forerunners used them for study after the war.

The Librarian even began to believe that humanity could attain the mantle - and she altered their Geas to promote their survival. She was behind history changing-events such as the SPARTAN program, Cortana, and humanities innate familiarity with Forerunner technology. Humans became Reclaimers.

But what of the other human species living within the Pleistocene? Florians, Neanderthals, Denisovans. Modern humanity consists entirely of -Yoink!- sapiens. They did not pull through to our recent epoch, as they all went extinct. Chackas, in the form of a monitor, even mentioned that modern humans had found fossils of -Yoink!- floresiensis (Florians).

Why did the Forerunners not ensure the survival of other human species through Geas, so that they could pull through to modern times? Forerunners can’t have only cared about -Yoink!- sapiens, because Denisovans were preserved on Installation 07 for study. And even if -Yoink!- sapiens are somehow “special” in the eyes of the Foreunner, what is it that makes it so?

I hope someone has an explanation for this; it’s really confusing for me.

The Geas doesn’t ensure that they will survive and succeed. It simply drives them to do certain things. Humanity could be wiped out before the culmination of the Librarian’s plan.

I’m guessing it was because those were all human subspecies. As far as the Librarian was concerned, it didn’t matter which of them made it through natural selection, as long as one of said subspecies–in this case, -Yoink!- sapiens–survived.

> I hope someone has an explanation for this

Other human empires among the stars

You have to remember that other planets and installations of humans were being cared for and looked after. The Humans of Erda were the ones that had the imprints which is why they were left on the planet.

> The Geas doesn’t ensure that they will survive and succeed. It simply drives them to do certain things. Humanity could be wiped out before the culmination of the Librarian’s plan.

Yet more proof that geas’ arent all controlling like some people think.

Geas’ probably did nothing to help avoid famine and other environmental factors.

Since they were just devolved Humans, I just assumed that they kept the species, -Yoink!- Sapiens, that Humanity would have naturally evolved to without Forerunner interference; that’s my interpretation anyway.

Humanity was one sub-species at the height of it’s empire, the Forerunners then shattered the species into it’s previous forms and sub-sets as punishment. I would imagine, that like our know evolutionary past, precursors to the Ancient-Humans also died out, leaving one dominant species.

Many human species
Ancient Humans
Many devolved human species
-Yoink!- Sapiens