Maverick Life

Who wants to live forever? (The immortal hydra already does)

By Emilie Gambade 5 June 2020

Hydra genus microagua (Image by CC BY-NC-SA)

Eternal youth and immortality have fascinated humanity since the beginning of time and our quest to beat biological ageing and mortality has been tenacious, albeit unsuccessful. Animals (which humans are) live and die, end of story. That was until one tiny animal proved us wrong.

“Who are we? What are we composed of? What is matter? What does matter? Is the body just a vessel with an expiration date?” asks American rapper GZA from Wu-Tang Clan, in Liquid Science, the show about science and imagination he hosts on Red Bull TV. In this episode, GZA is on a “quest to understand the human desire to live forever”.

Trying to find answers to such questions is nothing new. In an opinion piece for the Washington Post titled ‘‘Transhumanist’ eternal life? No thanks, I’d rather learn not to fear death’, Arthur C Brooks explains that, back in the fifth century before Christ, Greek historian Herodotus wrote about “a race of people in northern Africa who, according to local lore, never seemed to age”.

Eternal youth and immortality have always fascinated humanity, but we’ve not had much success finding them. Until now.

Professor of biology Daniel Martinez, from Pomona College in California, has spent his life looking at the strange and fascinating world of the hydra, a minuscule animal part of the hydroid family, tiny predators related to jellyfish.

Circa 1750, The Greek hero Heracles or Hercules cuts off the nine heads of the Hydra, a monster from the marshes of Lerna in Greece, while his friend Iolaus sears the stumps, to stop two heads growing back in place of the missing one. This was the second of the Twelv (Photo by Hulton Archive/Getty Images)

The hydra takes its name from the mythological Greek monster whose head grew back and multiplied if it was decapitated. The tiny hydra, though, has only two cell layers and very strong stinging cells, says Dr James H Thorp, professor in the department of ecology and evolutionary biology and senior scientist at the Kansas Biological Survey. But, like the mythical hydra, cut its body into pieces and it grows back into multiple hydras. Leave it and it never gets old. As Martinez explains in an interview with NPR, hydras “[are] just sitting on their leaves and just being immortal; waiting for nothing to happen forever”.

Hydras can be found in freshwater. “Most members of this phylum are in the ocean (corals, sea anemones and jellyfish). It is in an animal phylum (Cnidaria or Coelenterata) that lacks the ability to photosynthesize like algae, plants and cyanobacteria can. It is relatively primitive and the phylum is an offshoot of the path that eventually led to the evolution of vertebrates,” explains Thorp.

In 1998, Martinez published one – at the time controversial – paper, ‘Mortality patterns suggest lack of senescence in hydra’, that explained that “researchers have suggested that hydra is capable of escaping aging by constantly renewing the tissues of its body”.

Professor Daniel Martinez looking for hydras (Image courtesy of D. Martinez)

Since then, in his lab back at Pomona College, he has been looking at this odd and extraordinary phenomena. He explains, “The evolution of aging has intrigued scientists for a long time. How can a syndrome (aging or senescence) that has at first sight obvious negative fitness consequences for an organism be evolved? Shouldn’t natural selection oppose the evolution of aging? Under what circumstances may aging evolve? Should all organisms undergo aging? Bacteria, plants, animals? Studies of the mortality rates of the cnidarian hydra seem to suggest that hydra may lack aging. My lab is carrying out a long-term study of mortality rates in hydra to test the hypothesis that hydra may have indeed escaped aging. We are also studying two signaling pathways that have been implicated in the regulation of lifespan in other animals.”

Today, studies on the hydra suggest “the reason that hydra doesn’t age is not because of some substance that it has that protects the hydra from [aging], it’s just the make-up of the hydra; it’s a simple body made of stem cells”, says Martinez.

And if we had a body made of stem cells – in fact, we do have stem cells, in the brain and our muscles, that develop and can even fix damaged tissues – the chances are we could also be rejuvenating ourselves.

“That’s the secret. If we could have a body made of stem cells we could be immortal, too. But we cannot. And most bodies cannot. Because we’re not that simple,” says Martinez.

For our bodies to function, “we need cells that commit to do something and don’t go wild into dividing, otherwise we get cancer”, he adds. The hydra doesn’t need that. No commitment cells, just enthusiastic division and rejuvenation.

Though studies of the hydra might not have brought us eternal life, they have revolutionised the way we look at mortality.

“The dogma at the time was that all animals age. People thought, there is no way an animal will not age. That’s what we believed. After my study was published, we started to think that it wasn’t necessarily true, which was a big change. Now, to think humans are going to be immortal is a huge step,” Martinez says.

It is possible that, in the near future, beauty companies will try to sell us hydra creams, but there is zero evidence that they’ll hold the key to longevity. “Of course, someone can sell you hydra cream, but I doubt that it would help you at all. The best thing for us is: drink a lot, be happy, be in nature and enjoy what we have – you know, 100 years is a lot, so let’s just enjoy!”

Still, for many (especially the rich and the famous), fresh air, nature and water doesn’t quite cut it in terms of fighting senescence.

The transhumanism movement is best explained in Mark O’Connell’s book To Be a Machine. He notes, “It is their belief that we can and should eradicate aging as a cause of death; that we can and should use technology to augment our bodies and our minds; that we can and should merge with machines, remaking ourselves, finally, in the image of our own higher ideals.” Right now, that translates as 3D-printing for human augmentation, gene-editing, digital cloning …  a different world.

Arizona-based Life Extension Foundation, Alcor, is using a different technique: cryonics — “an experimental procedure that preserves a human being using the best available technology for the purpose of saving his/her life”. The process? Using very low temperatures in a procedure called “vitrification”, which involves an ice-free process in which more than 60% of the water inside cells is replaced with protective chemicals. This apparently prevents freezing during deep cooling. Instead of freezing, molecules just move slower and slower until all chemistry stops at the “glass transition temperature” (approximately -124°C).

Image: Cryonics Institute

About 140 people have been vitrified – either their full bodies or just their heads – hoping that in the next 200 years someone will be able to reverse the process.

In 2013, Google launched a health and anti-aging venture called Calico to study the aging process, hoping to “devise interventions that enable people to lead longer and healthier lives”, with a reported investment of $1.5-billion. But, in 2017, Vox said that beyond a rather vague mission statement no-one knew what Calico was doing.

Another Silicon Valley-based biotechnology company, backed by Jeff Bezos and Peter Thiel, is designing drugs to prevent people from getting sick with age-related illnesses. Unity Biotechnology is in phase two of clinical trials for a drug to cure osteoarthritis.

Right now though, humans still age and eventually die. And though many scientists the world round are still exploring the complex aspects of senescence, the secret to eternal human life might not be their ultimate goal.

As Thorp notes: “What do [I] hope to find? A happier and friendlier world led by people who have the best interests of the people in their hearts! Of course, from a scientific perspective, I hope to find answers to many questions that have intrigued me…” DM/ML

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