They're nihilists, Donny, nothing to be afraid of....
It's a characteristic of the human mind to turn simplicity into subjective complexity and to construe difficulty from life where none exists. Today the archetypal question for philosophers is "why are we here?" Ask a human and serious responses will probably involve complex reasoning involving mystical deities or introspective analysis. But before we leave the final answer with humanity I think we need a second opinion.
Some 280 million years ago the first amphibians began life outside water. These Labryinthodonts named for their infolded tooth enamel typically had large triangular heads and wide, flat bodies that looked like giant road-kill without the tread marks. Tetrapods like these crawled around on land eating worms, maybe a few bugs but basically whatever they could catch and digest. Not much to look at or admire yet they gave rise to all other land vertebrates, reptiles, birds, and yes eventually even literate humans.
If we could ask the same of a Permian tetrapod what mysterious, and enlightening answers would they provide? Perhaps something like "I don't understand the question, I just want to avoid death."
Odd isn't it that they never had any goal or god, no soul or hope of an afterlife indeed they lacked any purpose beyond the brief struggle for life and yet millions of years later here we are reading this because of it, because they existed and evolved. We as humans exist in the same physical universe, subject to the same rules of physics and biology, the same need for sea-water salinity body fluid, the same protein and amino acids ... Decades of scientific inquiry and careful research all to reach the inescapable conclusion that the point is there is no point. The joke is on us because we turned the absurdly simple into the dangerously complex. Indeed if scientists would or could get out of this loop they'd notice the likely conclusion that science itself is doomed because even archaic mythologies provided more appealing cosmic answers for public consumption!
The answer to "why are we here" is no different for human, Labryinthodont or jellyfish because we live in the same world subject to the same physical limitations and end up in the same place after death, well some leave better fossils than others. Now we see why fear of death is such a natural instinct and why religion exerts so much concerted effort to contradict that instinct.
The human mind creates ethics, moral codes, rules to die by, excuses and justifications for the deepest epiphany and the most trivial event alike. Some even go so far as to hijack random events and misinterpret them as self-created, the psychological principle known as 'illusion of control'. Unfortunately the complexities of the human mind merely make it easier to believe in fantasy and entertain delusion. Such an effort to find greater significance where there really is none and this only leads to wayward guidance and specious justifications. Those concocted reasons are then used to justify what need not be justified like our continued existence except based upon lies, setting up everyone for the fall when the myth erodes. Everything would move onward quite smoothly without any human minds around to believe in God, Satan or any other fictions, it did before us and it will after. Instead the Nihilist is concerned with the things that matter whether anyone believes in them or not; all those forces and factors that influence even the things that don't think.
Although evolution has no goal and our purpose may be just as elusive that doesn't void significance, it doesn't make action and consequence irrelevant, an important distinction too often confused within nihilism. Nihilism doesn't preclude significance or a naive refusal to extract lessons from history just as a lack of the traditional mystical goal does not necessitate futility. Extinction events for example are significant, after all we wouldn't be here without them. The only cosmic justification supported by any tangible evidence is the impetus for continued existence, the self-justifying purpose of tautology. And truthfully demanding any further justification from most simply foments confusion and foolish behavior. Furthermore it's likely that anything beyond that basal maxim is just an artificial construction. So, nihilism is not an issue of existence so much as a series of questions regarding the value if any that those artificially constructed meanings have. Where do they take us and do we really want to end up there? And can we really outsmart natural selection, for instance?