What If We Weren't Alone?

Homo sapiens and
Homo neanderthalensis

The question ‘are we alone in the Universe?’ has been pondered for decades. The Search for
Extraterrestrial Intelligence (SETI) is a collective term for the many forms of search that exist for intelligent life beyond our planet. Scientifically, the search began in earnest soon after the invention of radio.

What would we do if intelligent life were discovered elsewhere in our own galaxy or in other galaxies? How would we react? What would we think of our own existence? Would we react with fear, or with open arms?

Would we re-evaluate our own place in the cosmos? What about our life on this planet? Would we reconsider our place here on Earth?

Crucially, would we continue to think of ourselves as the supreme beings? Would we continue to think of ourselves as the Crown of Creation or as the Pinnacle of Evolution?

Of course, notwithstanding various conspiracy theories and ufology, there has not yet been any scientific evidence to confirm the existence of extraterrestrial intelligence. Nor, however, has there been any scientific evidence to confirm that extraterrestrial intelligence does not exist.

Are we alone? We don’t know, but so far, we seem to be.

Yet, we haven’t always been alone.

Just 100,000 years ago, right here on our home planet, we Homo sapiens were not alone. We shared the planet with at least five other hominins of the genus Homo. The longest living of these was Homo erectus who lived from around 2 million years ago up until the relatively recent time of about 100,000 years ago. Homo erectus was widespread throughout Eurasia.

Two of the others, Homo luzonensis and Homo floresiensis were confined to islands (Luzo in the Philippines and Flores in Indonesia respectively.) We, Homo sapiens, most likely did not know of the existence of these two long-lost cousins at the time they existed.

But the other two hominins, Homo neanderthalensis and Homo denisova we probably did know of, as well as interacting with. Homo neanderthalensis (the Neanderthals) roamed throughout Eurasia from (possibly) around 430,000 years ago until as recent as 40,000 years ago.

Homo denisova were an Asian species living from about 285,000 years ago until just 25,000 years ago.

We certainly did know of these hominin cousins. Indeed, we knew them quite well. Modern day Homo sapiens of European descent contain approximately 2% Homo neanderthalensis DNA. Homo sapiens from Asia, Melanesia, and Australian Aborigines contain up to 6% Homo denisova DNA.

Hence, as little as 20,000 – 40,000 years ago we were sharing our planet with two other species of Homo. We were sharing the land, trees, fruits, nuts, grains, and waterways with these cousins for some 80% to 90% or more of our existence.

What if those two species were still extant? Significantly, what if all five of them were still living and breathing somewhere on Earth?

We would have to re-evaluate our notions of superiority. We would have to recognise that we (Homo sapiens) had to share this planet with at least five other species within our genus. Recognising that, we might even begin to accept that we needed to share this Earth with other-than-human species.

A corollary to this thought experiment is the question of why these other five species of Homo died out? The reason is chilling.

A study in 2020 strongly suggests that the extinction “coincides with increased vulnerability to climate change.”¹ In the case of Homo neanderthalensis competition with Homo sapiens at a time of severe climate change appears to have hastened their demise.

The study further suggests that we (homo sapiens) managed to survive the climate change of the time because we were the “only species whose climatic niche was still expanding … when the Neanderthals went extinct.”

Nowadays, however, we have nowhere further to expand. Climate change affects everyone, everywhere. We are the latest of the Homo genus, we may well be the last.

Unless we change how we perceive of ourselves and if we were to think of ourselves as not alone.

Note:

1. Pasquale Raia et al., Past Extinctions of Homo Species Coincided with Increased Vulnerability to Climatic Change, One Earth 3, 480–490 October 23, 2020.