Immortality And You: The Science Of The Everliving
The Arch Priest knelt before the body on the floor, its form captured all too well in the revealing moonlight. Every line of mortality, etched onto the corpse…a reminder of the futility of flesh. The curse of blood and bone, forever cursing in the veins of most of the life on this planet. But the Arch Priest did not care: his fate was not to follow the same demise as this poor, misguided fool. Power…power did not come in having the deepest pockets, the largest armies, or the brightest mind…no, power was in doing what others did not have the courage to do. THAT, the Arch Priest knew through his experiences, was true power. He brushed aside a part of his robe, revealing a black belt around his waist. Whilst it held many items of questionable moral value, it was the sheathed dagger that the Arch Priest drew out now. His long, vulture-like fingers grasped the jewelled hilt, feeling the cursed blade’s energies seep into his body. He closed his eyes took a moment to savour it, let the raw, undiluted power course through his veins, feeding his very soul. Slowly, his eyes opened. In a trance, he felt the dagger in his hands, poised over the corpse…ready to eat its fill…
Moments later, the Arch Priest’s body radiated with energies that he was a complete stranger to. He laughed, softly at first. The laugh grew louder, more maniacal…if others were there witnessing this odd scene, they may have even called it demonic. The Arch Priest turned his attention towards an unknown adversary, savouring each word as he spoke: “Do you see now, Jorn? Do you see how pathetic and fragile you and the rest of your Kingdom are? I have become an example of what our species must aspire to in order to survive. I. AM. IMMORTAL!”
The last words that the Arch Priest spoke rung out in the cathedral…as he felt the unforgiving kiss of the blade between his shoulders, and darkness was all he would ever know again.
Without the melodrama and the potential maliciousness (or with it included, as you will), the above, completely original anecdote, highlights our species’ quest for immortality. That is, it’s a bit of a fool’s errand. OK, granted that not all of us are chasing after immortality, but it is certainly something that intrigues most of us. The ‘what if’s’ are just too juicy to leave alone. Now, there is potential for human immortality, a team of Russian scientists are pleading to millionaires to help them try to break the ‘immortality barrier’ – which they’re hoping to break by 2045. In essence, their work focuses on cybernetics and artificial bodies – so less like the hypothetical story featuring our megalomaniac Arch Priest above and more like the film Surrogate (with Bruce Willis). In typical, internationally competitive fashion, the Americans are also apparently working on a similar project. Nothing like a bit of healthy competition to forward scientific advancement!
That’s all very well, but where does that leave us? Well, we can safely assume that we have prospects of immortality at the moment. Of course, I’m talking purely from a biological level, acknowledging immortality has many different definitions based on beliefs (e.g. the soul). That being said, it isn’t like Mother Nature hasn’t already delved into the whole issue herself (she’s the best mum around!) and produced a few interesting results for us to ponder over! Without further ado and in no particular order, I present today’s selection of animals for review, under the theme of IMMORTALITY!
1) Tardigrada/Tardigrades – Water Bears
I remember the first time I saw one of these loveable little scamps. It was during a two week, intensive Marine Biology course at Millport Station, located in the Isle of Cumbrae, Scotland. It took forever to try and get a proper sample that we could study under the microscope, and even then we fell short. Luckily for my lab/field work partner and myself, a fellow peer had managed to isolate one of these amazing specimens and fixate it onto a slide. Now, at this point, both my partner and myself were losing hope in humanity as we had been stuck on this island for way too long without our beloved Playstation. However, speaking for myself, the moment my eyes laid themselves upon the water bear on our slide, I was instantly fascinated…what was it? Where had it come from? What was its biology? Did it like Kevin Spacey’s performance as Verbal Kint in The Usual Suspects? So many questions!
Tardigrades, also known as water bears, number about 900 species that have been discovered thus far. Water-dwelling animals that are pretty much found anywhere where this is water, they are polyextremophiles. That is, they thrive on, perhaps even love, conditions that would otherwise kill most life on Earth. Spiffing. They’re also the most complex polyextremophiles around, so they’re not to be taken lightly (despite generally having a low mass due to their small size). Although they have a lifespan of two months, going up to two and a half years, tardigrades are able to undergo a particularly interesting biological process which helps them to survive where other life cannot: like, you know, space.
The process is known as cryptobiosis. It involves reversibly stopping all metabolic processes, surviving in a dehydrated state where they are barely ‘alive’. A tardigrade undergoing cryptobiosis is known as a ‘tun’. They can survive in this condition for years, although the exact amount of time they can remain in a dehydrated state is down to other factors, chiefly the presence of the sugar trehalose, which protects their membranes. Of course, coupled with their average lifespan, it’s difficult to tell just how ‘immortal’ a tardigrade is. But they have more than earned their place in the Immortal Hall of Fame thanks to their ability to survive in pretty much any condition: the low pressures of space, high pressures, absolute zero, incredibly scorching temperatures. And we complain whenever we get a day in Britain that’s hotter than we like it or colder than we like it!
2) Turritopsis nutricula – The ‘Immortal Jellyfish’
Scared of being stung in the water by a jellyfish whenever you take a dip in the sea? Well, you might have further reason to fear dipping in those inviting waters after hearing about this particular animal! T. nutricula. To explain just how this animal is biologically immortal, a bit of Cnidarian biology has to be explained. Cnidaria are a group of approximately 10,000 animals that inhabit aquatic and marine environments. This group include sea anemones, corals, sea pens and jellyfish (of course). The life cycle of a Cnidarian includes a sessile (immobile), polyp stage, which is also the ‘sexually immature’ stage. A good example of this stage is a coral polyp. The other stage is the ‘medusae’ (plural: medusa) stage – and no, it has nothing to do with witch-like ladies with petrifying snakes on their head. This is the mobile, sexually active stage – a good example being jellyfish.
Now, the polyp and medusae stages of the life cycle are separate, yet T. nutricula has an interesting way of turning the life cycle back on itself to achieve biological immortality. Essentially, this clever jellyfish, once at the sexually mature medusae stage, undergoes a process called ‘cell transdifferentiation’. This is where the mature jellyfish’s cells biologically revert back to polyp cells. So far, laboratory experiments have shown that 100% of all individual T nutricula organisms are able to do this process. You have to admire the simplicity of the idea: turning back the biological clock, quite literally, for its cells to become a polyp again. Of course, I purposely used the term ‘biological immortality’, as predation and disease can still pose a problem to that old process which we call living. Still, this animal has to be admired!
3) Hydra spp. – simple, freshwater animals
Note: spp. simply means ‘species’, in its plural form. It means ‘all the species of this genus’, where the genus name is put before ‘spp.’. So Hydra spp. means ‘All species of the genus Hydra’, just as Homo spp. means ‘All species of the genus Homo‘.
These animals deserve a prize for sparking off my curiosity in biological immortality. Way back when I was an A-Level student with more curiosity than knowledge (actually, that’s still true now), I was captivated by the simplicity and the beauty of these creatures. And I was extremely fascinated by their ability to reverse the process of senescence (otherwise known as aging). To undergo non-senescence (effectively, not age), Hydra make full use of the FoxO gene, a gene that plays a key role in maintaining stem cells. This gene is present in our DNA as well. Furthermore, Hydra also reproduce via a process of asexual reproduction, called ‘budding’. With each new polyp that buds from a Hydra individual comes a new source of stem cells that are sources of continuous regeneration. So, in essence, Hydra, thanks to both budding and the FoxO gene, can fight off the wrinkles with fairly minimal effort. As with T. nutricula, Hydra are biologically immortal, but can just as easily succumb to factors such as predation and disease.
Immortality may be a pipe dream currently for us humans, but the animal kingdom is still showing us just how much further we have to go in our pursuit of knowledge and, in some respects, power. Okay, I don’t mean power like that of my imagined Arch Priest at the beginning of this post. I mean a certain power over natural processes, although it is debatable how much power we should have over certain biological processes, such as ageing. Still, we can draw inspiration from the natural world and attempt to make leaps and bounds in science that can help to advance society. As long as we do it ethically, and with the intention of being self-aware of our impact, then perhaps the only limit is our own imaginations. After all the practicalities and logistics and so on and so forth…