In terms of the history of biological enquiry, I don’t know, but I think I know why the mind picks at things like the discovery of stalagmite constructions created by Neanderthals in a French cave 100,000 years before modern humans arrived in the area (they must have caught the 4am booze ferry).
It’s presumably the same instinct that drives UFOlogy and extra-terrestrial life investigation generally. We long to discover that sentient life exists in the universe, and our wildest dreams (our most terrible dreams, often) are that this life is self-aware. We want on a cosmic scale to find people like-us-but-not-like-us. We crave the perspective of others because it enables us to (re)create and define ourselves. The idea that there might have been Others in prehistoric eras who, to some extent, shared something of our instincts, our inner lives, our Feeling of What Happens, and the idea that these people are now both gone and, the intriguing inside-job opposite, incorporated into us, is an irresistible one – at once cautionary tale (“there but for the grace of the universe…”), congratulatory just-so story (“we survived, we won this race, we’re great!”) and also a delicious, mysterious, self-othering fairy story.
Perhaps literally fairy story. I have (you must tell me if you have the same) an inner longing I can’t explain for it to be true that some of the humanlike-but-other creatures populating the mythologies of North West Europe, like fairies, giants and elves, are our folk memories of Neanderthals and perhaps other hominins. I suspect this interpretation is scuppered by the simple fact that corresponding creatures are found in folklores across the globe, including in regions where modern humans did not co-exist with Neanderthals. And yet… It’s not that I’m obsessed with explanations and root causes, it’s almost the opposite – to find that fairy stories were true would almost make them more magical. Just think – to discover that we regularly in the most trite and childish fables tell ourselves as much about history, the universe and ourselves as we go on to (re)learn in later years of scholarly endeavour? Amazing. That is some impressive symbolic capacity our brains have developed there. What else can we learn from the simplest stories?
So while I’ve no idea whether the distinction between gloomy octopus and common octopus is a valuable one to anyone other than a marine biologist, I think it is clear there are particular implications of speciation within the Homo genus that are philosophically momentous and, on the grand scale, viscerally personal for us. Are/were these people like us? How like us were/are they? What do they think of us? What can they tell us? What do they know?
Of course this is obviously all a metaphor for how human beings relate to each other on an individual level – we seek each other because even the most grounded of us need reflection and differentiation. On an individual scale, people-who-are-like-us-but-not means literally anyone else at all. Or maybe really it’s the other way round, our individual drive for connection with each other is a rather pale and small-scale metaphor for our collective drive for defining ourselves and our consciousness in the universe. As, for want of a better word, a species.