My apologies ahead of time for being a sutta nerd.
Bhikkhus, I do not see any other order of living beings so diversified as those in the animal realm. Even those beings in the animal realm have been diversified by the mind, yet the mind is even more diverse than those beings in the animal realm.
“Therefore, bhikkhus, one should often reflect upon one’s own mind thus: ‘For a long time this mind has been defiled by lust, hatred, and delusion.’ Through the defilements of the mind beings are defiled; with the cleansing of the mind beings are purified. -SN 22.100
In his end notes for the above, Bhikkhu Bodhi discusses the likelihood that this is a description of how it is past action that contributes to what is possible in the animal realm, and from that point of view it is the defiled mind that generates the potential for diversification.
Then there’s AN 10.29:
There comes a time, bhikkhus, when this world dissolves. When the world is dissolving, beings for the most part migrate to the devas of streaming radiance. There they exist mind-made, feeding on rapture, self-luminous, moving through the skies, living in glory, and they remain thus for a very long time. When the world is dissolving, the devas of streaming radiance rank as the foremost. But even for these devas there is alteration; there is change.
Which takes us right into DN 27, beginning with the same description:
There comes a time when, Vāseṭṭha, after a very long period has passed, this cosmos contracts. As the cosmos contracts, sentient beings are mostly headed for the realm of streaming radiance. There they are mind-made, feeding on rapture, self-luminous, moving through the sky, steadily glorious, and they remain like that for a very long time.
There comes a time when, after a very long period has passed, this cosmos expands. As the cosmos expands, sentient beings mostly pass away from that host of radiant deities and come back to this realm. Here they are mind-made, feeding on rapture, self-luminous, moving through the sky, steadily glorious, and they remain like that for a very long time.
The moon and sun were not found, nor were stars and constellations, day and night, months and fortnights, years and seasons, or male and female. Beings were simply known as ‘beings’. After a very long period had passed, the earth’s nectar curdled in the water. It appeared just like the curd on top of hot milk-rice as it cools. It was beautiful, fragrant, and delicious, like ghee or butter. And it was as sweet as pure dwarf-bee honey. Now, one of those beings was reckless. Thinking, ‘Oh my, what might this be?’ they tasted the earth’s nectar with their finger. They enjoyed it, and craving was born in them. -DN 27
Soon after, as a result, those beings lost their luminosity, and what amounts to more of a degeneration continues until we finally see the sufficient conditions for humans. So, if we put DN 27 and AN 10.29 into the light of the passage from SN 22.100, it is only a matter of time before the former diversification of mind manifests at that individual level.