The Other Half of Science

This time each year, I take the liberty of posting something more speculative and personal.  In this essay, I propose that everything we consider the “scientific world-view” is only half the story, and that science must expand its foundations if it aspires to  be a complete account of reality.  

A reductionist approach to science has become so ubiquitous that many scientists find it difficult to imagine that science can be done in any other way.  Interactions among elemetary particles are the ultimate explanation, the only final cause.  Biology can be reduced to chemistry.  Chemistry is the science of large numbers of atoms, interacting according to the laws of quantum physics.

But reductionism is only a habit of the way we do science.  It is logically possible that there are global laws, interconnections, entanglements; and that these are discoverable by investigation that is rigorously scientific .  Teleology is commonly dismissed as “unscientific”, but it is precisely teleology that we may need to explain a host of diverse findings that conventional science has swept beneath the carpet.

Camille Flammarion 1888 copy of 16th Century woodcut. Bettman Archive calls it “Man Looking into Outer Space” Original artist unknown.


One of my oldest friends is a professor of computer science at a great mid-western university.  An Israeli-American, Uri is descended on his mother’s side from an ancient line of Kabbalist mystics, but his philosophy is strictly materialist.  He believes that “the mind is what the brain does”, that the brain is a computer, and that electronic computers can be programmed to do anything that our brains can do.  Like a great majority of computer scientists, he believes that subjective consciousness is something that arises when computation attains a certain kind of complexity.  

Last summer, Uri told me a story from his youth.  In college, he had dated a young woman, a passionate political activist.  Years after he had lost touch with her, she sunk into depression with the election of Ronald Reagan.  Uri awoke one night, sweating and screaming, from a nightmare in which she had jumped from a building.  Though he had not talked to her in several years, he reached out and tried to contact her the next morning, and her parents informed him she had killed herself that very night, jumping from the window of her apartment.  Uri was shaken at the time, but he has filed the experience in his memory as a coincidence, a curious anecdote with no particular message about the way our world works.

Sitting in a canoe, listening to Uri’s story, I asked him if he thought an artificial intelligence might ever have such dreams.  What would he think if his story and many like it were collected in a stastical database, and it could be demonstrated that such “coincidences” were far too frequent do be dismissed, that their composite probability was far rarer than “five sigma” (roughly “one chance in a million”), which is a conventional threshold for announcing that physics has discovered a new particle.  He responded thoughtfully:  He didn’t have time to do that kind of analysis.  It depends on so many people’s stories, and people’s memories of such things aren’t so reliable.  But if it could be established, he said, he would be forced to conclude there were new sub-atomic forces that brains can use to communicate, and that physics had not yet discovered.  In any case, he was committed to the idea that reality is physical — space, time, matter and nothing else — and that every phenomenon of nature must be explainable in reductionist terms.  By definition.


How Science came to be narrow-minded, with universal ambitious

Don’t doubt the Creator, because it is inconceivable that accidents alone could be the controller of this universe.
— Isaac Newton

Newton’s scientific ambition was prodigious.  He first conceived the idea that the universe was governed by precise mathematical laws that were independent of place and time.  But he never imagined that physics was a complete picture of the world.  It was only in the 19th Century that the idea took hold that physical law might explain everything.  Science had been enormously successful in accounting for diverse phenomena, expanding again and again to explain more of our world.  Then scientific philosophy made an audacious leap: Every phenomenon in our universe is regular.  All of our experience can be accounted for in terms of deterministic mathematical laws.

Is this statement true?  We all assume it is.  But in fact, it is an empirical statement, a bold one, to be sure, and all the more reason it should be challenged and tested experimentally.

Of course, it’s not literally true that two experimenters doing the same experiment always find the same result.  There’s experimental error—mistakes and misjudgments that enter any human enterprise.  And in biology, there is the complication that no two organisms are exactly alike.  These things were understood and accounted for in the Nineteenth Century.  This was the time when “vitalism” was stripped out of biology, and living things were boldly assumed to depend on the same mechanistic laws as non-living matter.  Biology was conceived to be built upon chemistry, and chemistry could be understood as the interactions of atoms.  It was at the level of atomic physics that the Universal Machine operated in a manner precisely determined by mathematical laws.

But 20th Century science shattered determinism.  The Scientific World-view retreated just far enough to allow for quantum randomness and the Heisenberg Uncertainty Principle.   

“Philosophers have said that if the same circumstances don’t always produce the same results, predictions are impossible and science will collapse. Here is a circumstance that produces different results: identical photons are coming down in the same direction to the same piece of glass. We cannot predict whether a given photon will arrive at A or B. All we can predict is that out of 100 photons that come down, an average of 4 will be reflected by the front surface. Does this mean that physics, a science of great exactitude, has been reduced to calculating only the probability of an event, and not predicting exactly what will happen? Yes. That’s a retreat, but that’s the way it is: Nature permits us to calculate only probabilities. Yet science has not collapsed.”

— Richard Feynman

To Einstein’s consternation, God does play dice with the world.  When the Twentieth Century discovered quantum indeterminacy, most philosophers of science made the minimal modification to their deterministic picture.  To them, the future state of the universe is determined by its present state plus pure chance.  In this paradigm, there is nothing outside physics, or if there is such a thing as “soul” or “spirit” or “free will”, it is irrelevant to science and to experience.  It can have no observable effects, because the physical universe is a closed system, governed perfectly by a combination of deterministic laws and pure chance.

This is the philosophy of “materialism” or “physicalism” that has become synonymous with the scientific world-view today.  But it is far more explicit than the original scientific world-view, which says only that our knowledge of the world depends on empirical observation plus mathematical logic.  In fact, the original scientific world-view is a system for discovering truth, but it is silent about what that truth ought to be.  This expanded scientific world-view is not just a statement about methods, but contains a description of the nature of the world.  It is a scientific theory, in the sense that it says something about the empirical nature of reality.  Like all scientific theories, the expanded scientific world-view can never be proven true, but it can be falsified by observation.

The original scientific world-view as bequeathed to us by the Enlightenment is an epistomology which we can accept or reject, but no arguments can be adduced for or against it.  The expanded scientific world-view is a statement about the world, and we may legitimately ask, “Is it true?”


Reproducibility

The issue of reproducibility is the crux of the matter, and it is related to science in two ways.

http://www.musingsone.com/2015/09/why-most-published-data-are-not.html

On the one hand, science seems to depend on reproducibility, at least in the statistical sense.  If different experimenters at different times and places get different results from the same experiment, how can we ever hope to come to agreement about the world we live in?  Reproducibility—in the expanded, statistical sense—seems to be a necessary feature of the world if we are to be able to study the world with science.

On the other hand, we may treat reproducibility as an empirical question.  Is it true that the same experiment always results in the same results, at least statistically?  To rephrase more provocatively:  Is it true that the universe is governed by scientific laws that always hold true, or are there exceptions and one-off happenings, things that occur sometimes but without a regularity we can codify?

We might ask, “are miracles real?”  Should the scientific world-view take a firm stance on this issue and answer, “No!”?  Or should science be open-minded, and consider the possibility that those who report miracles are not always deluded or mistaken?

Evidence that we need a new model

From one stage of our being to the next
We pass unconscious o’er a slender bridge,
The momentary work of unseen hands,
Which crumbles down behind us; looking back,
We see the other shore, the gulf between,
And, marvelling how we won to where we stand,
Content ourselves to call the builder Chance.
— James Russell Lowell

There is no shortage of credible reports that cannot be explained by the reductionist paradigm of science, but most have been shunted out of the mainstream journals, attacked or simply ignored.

Perhaps you have had a dream or premonition similar to Uri’s.  If not, you probably know someone who has.  It has become common for scientists to dismiss “anecdotal evidence” without feeling a need to explain it.  This comes from a ubiquitous assumption that all experiments are replicable — exactly the assumption which I think we need to challenge.

Daryl Bem is an emeritus professor in the Cornell Psychology Dept, recently retired after a long and distinguished career doing mainstream research about stimulus and response.  In one of his last publications, he broke into a well-regarded psychological journal with an article that documented responses in human subjects that preceded the stimulus.  This is precognition.  The subject’s subconscious knew or sensed what image was about to appear before him on a computer screen.  Julia Mossbridge summarized a substantial body of research, which collectively corroborates the reality of precognition with 99.999999999% certainty.

Robert Jahn, retired dean of the engineering school at Princeton University stumbled (through his student’s term project) upon evidence for the ability of human intention to affect probabilities that ought to be “quantum random”.  Jahn had the curiosity to investigate further.  When the anomaly wouldn’t go away, he refined the experiment and collected data over 30 years, by which time his results had achieved 5-sigma statistical significance — on a par with evidence for the Higgs Boson.  Jahn was ostracized and ridiculed, and colleagues began to discredit his work in aerospace engineering based on his willingness to openly consider the possibility that the human mind might be able to affect quantum processes outside the organism.  

Dean Radin has conducted a broad array of experiments that demonstrate different aspects of telepathy, precognition and telekinesis.  He has a background in physics, and routinely takes extraordinary measures to guarantee the isolation of his experiments from extraneous physical influences.  In one recent project, he found that focused attention of a person who is not in physical contact with the equipment can shift interference fringes of laser light passing through two slits.  This connection between thought and quantum is akin to results reported by Jahn.

Outside the world of parapsychology, there are uncontroversial animal behaviors that defy explanation.  Fish, turtles and cetaceans routinely navigate thousands of miles through the ocean, their guidance system unknown to science.  Each fall, a generation of Monarch butterflies is able to retrace the 2,000-mile migration path flown by their great, great, great grandparents six months earlier.  Flatworms have been conditioned to respond to light, then they are ground up and fed to other flatworms, who acquire some of the conditioning through cannibalism [skeptic’s account].

Dozens of labs around the world have successfully replicated the cold fusion experiments of Pons and Fleischmann.  Reports of their work are sequestered in this on-line journal because mainstream physics journals have declared that cold fusion is impossible.  In fact, there is nothing in fundamental physics that precludes cold fusion; it is, after all, a highly exothermic reaction, and the energy release is exactly as predicted. But cold fusion implies a new bulk quantum effect (akin to superconductivity, superfluidity and lasers) for which there is yet no theory. [video summary]  The physicist who taught me quantum mechanics at Harvard was a Nobel laureate who became irate when the American Physical Society refused to publish his proto-theory of cold fusion.

Ian Stevenson and Jim Tucker are medical doctors who have each spent decades investigating cases “suggestive of reincarnation”.  Children recall past lives, with details about the circumstances of that life that are later corroborated.  Stevenson noted the frequent presence of birthmarks where former selves suffered trauma at death.  Helen Wambach and Carol Bowman have used hypnosis to help adults find access to information about past lives.

The ganzfeld protocol is the most reliable experimental procedure for demonstrating telepathy.  A meta-analysis of 59 ganzfeld studies reports a combined success rate of 30% in identifying a target photograph when the chance hit rate should be 1 in 4.  The improbability of this result has been calculated in different ways, with results from 10-12 to 10-8.


Through a glass darkly:  Where post-reductionist science is headed

All the progress in science since the Enlightenment has built on a reductionist paradigm: breaking down the whole into parts, explaining the parts in terms of influences that are nearby in time and space.  If this is not the whole story, then we might imagine there are relationships among distant events.  There might be large-scale patterns that cannot be explained as “emergent” from local laws.  There may relationships that appear to us as retrocausality.  There might be destiny.

It is clear to me that what physics calls “quantum random” is not random at all, but rather is determined non-locally, via quantum entanglement.  Events distant in time and space are linked in a manner that baffle our usual methods of scientific inquiry, but that may be discoverable by a new kind of science.

There is nothing un-scientific about such a hypothesis, and in fact quantum mechanical “entanglement” suggests that such patterns must exist.  David Bohm has laid foundations for a science based on holistic patterns in an Undivided Universe.  He offers us a beginning toward understanding an “implicate order” that may complement the explicit order in time and space that is the basis of all of mainstream physics.

The Constellation, by Joan Miro

Possibly related is the idea that mind has an existence separate from matter, that free will operates in a sphere that is able to influence matter on a quantum level.  This could be a resolution in Cartesian dualism of David Chalmers’s hard problem.  One link between the realm of the self outside of space and time and the realm of physical matter could be through the quantum mechanics of the brain.  Roger Penrose and Stuart Hameroff have proposed a model.  Stuart Kauffman cites evidence that neurotransmitters in the brain are poised on a quantum knife edge where their behavior is dictated either by randomness (in the conventional view) or could this be the portal by which intention enters into physical behavior?

It may turn out that life is not an opportunistic parasite in a vast, cold and meaningless cosmos.  Life may be built into the laws of physics at the very foundation.  It may be that living behaviors are woven into the fabric of the cosmos.  Or it may be that awareness and free will live in a realm separate from time and space, but linked to physics at the quantum level.  This would be a way to resolve the Anthropic Coincidences without resort to an embarrassment of universes.

These ideas are not un-scientific, but they are difficult to study with current scientific methods.  At the dawn of the Twenty-first Century, experimental science is bursting at the seams with phenomena crying out for an expanded scientific paradigm.  The crisis will not be resolved by keeping speculative science out of the mainstream journals.  It is not likely to be settled by a brilliant guess about the nature of reality that resolves all our anomalies in one fell swoop.  The only way forward is for science to expand its methods and entertain a broad array of wild, new ideas, most of which are bound to fail.  But if we open the gates to speculative ideas, if we shake off taboos about teleology and holism, if we broaden the scope of experiments and our ways of understanding them…then I trust that our collective brainpower will be up to the task of formulating a picture of the world that comprehends a greatly expanded — dare I say “wondrous” — vision of our world.

The Varieties of Aging in Nature

In 1999, I met Cynthia Kenyon for the first time, and she told me her one-line proof that aging is an evolved trait.  Lifespans in nature range from hours to thousands of years. This shows that natural selection is not constrained, but can implement aging on whatever time scale is appropriate.

A few years ago, Annette Baudisch added another dimension to this proof: It’s not only the duration of life, but the shape of the aging curve that takes on so many various forms.  Misguided theories of aging are based on the human life cycle (and others like it) with Gompertz mortality.  (In the 19th Century, Benjamin Gompertz first noted that risk of death increases exponentially with age.)  Several smart theorists have been seduced into attempting proofs—either from thermodynamics or from evolution—that gradual aging is a necessary consequence of the conditions of life.   

But Baudisch gathered data on hundreds of animals and plants, demonstrating that the exponential shape of the human mortality curve is just one among many possible.  Furthermore, every conceivable shape is paired with every time scale.  Any theory of aging must account for all these ways to age.  Or not to age: Baudisch got her start in research collecting examples of negative senescence.  Given this variety, the only viable theory is, “nature can do whatever she wants”.  More formally, natural selection can mold aging as appropriate to fit every possible niche in every ecology.  


Aging is ancient, but it is not universal.  We are accustomed to think that animals age gradually beginning at maturity, ending with inevitable death, but life is stranger than this.  Some animals and many plants have escaped from aging entirely.  Many more pass through long periods of their lives without aging.  Cicada nymphs mature underground for seventeen years, while not being subject to increasing death rates or aging in any other sense.  Then the cicada emerges, mates, ages and dies all in a single day.  This is a dramatic example of semelparity, in which aging occurs all in a rush after a single burst of reproduction.  In many such cases, the aging can be experimentally decoupled from the reproduction, demonstrating once again that the aging is a separate adaptation.  The simplest example of this is the pansies in your garden.  As long as you snip off the flowers before they go to seed, you can keep the plant blooming all summer.  

Snipping off flowers before they go to seed will keep the plant alive all summer.

Many plants and animals  die when they are done reproducing, as evolutionary theory predicts; but among those that long outlive their fertility, there are some (like C. elegans worms) that don’t tend to their children or grandchildren.  What evolutionary force has provided for their continued life?

A few animals and many plants don’t age at all, but grow larger and stronger and more fertile through their entire lifespans.  Some have been observed to regress from mature states, and start life anew as larvae, with a full life expectancy ahead of them.

 

What does life without aging look like?

Sanicula is a shrub growing in the meadows of Sweden, and one plot in particular has been studied continuously for seventy years. Sanicula has a life expectancy comparable to a human, but sanicula does not age.  For people, the probability of dying gets higher with each passing year, whereas for sanicula, about one shrub in 75 dies each year, irrespective of age.  A 75-year-old plant has no more mortality risk than a 10-year-old plant.  For a person, the life expectancy at birth might be 75 years; the life expectancy for someone 60 years of age might be 18 more years, and for someone 80 years old, perhaps the life expectancy is 7 more years.  For a sanicula, the life expectancy of a seedling is 75 years, and the life expectancy of a 60-year-old shrub is 75 more years.  There are, in fact, a few 200-year-old saniculas, and they have a life expectancy of 75 more years. At this rate, about one plant in a million should live a thousand years.  A thousand-year-old sanicula is no closer to death than a sapling.

It is unknown today whether lobsters age or not.  Lobsters are fished so heavily that they rarely grow larger than a pound, but lobsters weighing more than 5 lbs are still caught occasionally (and usually released). The largest lobster on record was 44 lbs. The reason that the large lobsters are released back into the ocean is not just that they won’t fit on a dinner plate. Lobsters become more fertile as they grow larger, and their young are more viable. A few large lobsters can be the breeding stock for a large area. We don’t have an age record for the oldest lobster ever caught because lobsters don’t have annual rings or layers that broadcast their age. The 44-lb animal was said to be more than one hundred years old, but no one knows for sure.

…and not the largest on record, either.

Clams also can grow larger and more fertile indefinitely. But clams have growth rings that count the years for us. The oldest clam on record (an ocean quahog of the species Arctica islandica) has been tagged at 507 years. Small clams have natural predators, including starfish that latch onto their shells and pull them apart by brute force. But once a clam outgrows the arms of a starfish, it can keep growing indefinitely. Clams have one foot, one mouth, no eyes or ears or stomach, no brain. Giant clams, up to 800 lbs, live the same lifestyle as their smaller relatives, sucking in the seawater, taking in thirty thousand times their weight in water every day, and filtering out plankton and algae, which continue to grow and reproduce inside them. Like giant lobsters, the giant clams provide eggs for a whole community. They have been known to release half a billion eggs in a day.

Giant clams can live hundreds of years.

All of the longest-living species in the world are trees.  There are several reasons for this.  Trees invest a great deal in growth, always trying to project their leaves upward, out of the shade of other trees, to compete for the best light.  The oldest trees tower above the forest, and get first dibs at the sun’s energy.  So there is a powerful evolutionary incentive for trees to live a long time so they can grow taller than their competitors, and the sky is the limit.

As opposed to plants, animals’ life spans are limited by a requirement of ecological stability.  Most plants produce their own food, but all animals depend on other species (either animals or plants) for their food.  Hence it is natural for a plant to live as long as possible and make as many seeds as it can make.  Trees are the best examples of Darwin’s dictate that life is about reproduction.  (Sequoia trees can produce more than a billion seeds.)  But animals can’t get away with reproducing faster than the plants at the base of the food chain.  Animals are evolved to guard the species lower down on the food chain, and they must never reproduces faster than the animals they eat—otherwise, in a very few generations, they will wipe out their food source and their children will starve.

View post on imgur.com

Do trees age at all?  Some do, and some don’t. Most trees go for long periods of time growing ever larger and less vulnerable to death.  That counts as negative senescence.  Of course, size itself becomes a hazard as a tree becomes the tallest in its grove—the first to be struck by lightning, the most top-heavy and vulnerable to toppling in the wind when erosion weakens the roots’ hold on terra firma. But in addition to this, it seems that most trees have a characteristic age, after which death finally becomes more likely with each passing year. There is some indication that trees become more vulnerable to fungus and disease with old age, but for the most part, old trees succumb to the mechanical hazards of excess size. The very ability to continue growing that offers them the possibility of “reverse aging” over so many decades proves in the end to be their downfall.

 

Instant Ageing; Sudden Death

Semelparous animals and plants reproduce just once in a lifetime, usually followed promptly by death. Sudden post-reproductive death is common in nature, affecting organisms as varied as mayflies, octopuses, and salmon, not to mention thousands of annual flowering plants.

The cause of death in semelparous organisms varies widely.  Theorists once assumed that the animal just wears itself out in a burst of reproductive effort, but this idea has not held up.  The burst of reproduction and the sudden death seem to be separable and independent adaptations. In addition to the example of pansies mentioned above, octopuses can be induced to live beyond their burst of reproduction if their optic gland is surgically removed; and Atlantic salmon, close cousins of the Pacific salmon, also endure treacherous migrations upstream in order to mate, but they don’t necessarily die after laying eggs, and can return to the ocean for another bite at the apple.

Chinook salmon hatch in river pools, often hundreds of miles upstream from the sea. They spend their first year or two in the protected environment of the river, where life is tamer and larger predators rarer. When they have grown large enough to compete, they migrate downriver, out to the ocean to seek their fortunes. They may range up to 2,500 miles from the mouth of the stream where they first entered the sea. They live in the ocean anywhere from two to seven years, growing larger but not weakening or becoming frail with age. When they are ready to reproduce, they find their way back, not to any handy river mouth but to the very same river pool where they were hatched. Their journey is a headlong rush, simultaneously into fertility and death.

Salmon fight rushing water to return to their spawning ground.

By the time the adult salmon reach their spawning ground, their metabolisms are in terminal collapse. Their adrenal glands are pumping out steroids (glucocorticoids) that cause accelerated—almost instant—aging. They’ve stopped eating. Moreover, the steroids have caused their immune systems to collapse, so their bodies are covered with fungal infections. Kidneys atrophy, while the adjacent cells (called interregnal cells, associated with the steroids) become greatly enlarged. The circulatory systems of the rapidly deteriorating fish are also affected. Their arteries develop lesions that, interestingly, appear akin to those responsible for heart disease in ageing humans. The swim upstream is arduous, but it is not the mechanical beating that fatally damages their bodies. It is rather a cascade of nasty biochemical changes, genetically timed to follow on the heels of spawning. The symptoms affect both males and females, despite the uneven share of metabolic work that falls to females, whose eggs may constitute a third of their body mass during the final leg of their trip.

Some organisms are genetically programmed not to eat after reproduction and starve as a result; it’s quicker and surer than traditional ageing. Mayflies entering adulthood have no mouth or digestive system whatever. Elephants chomp and grind so many stalks and leaves during a lifetime that they wear out six full sets of molars. But when the sixth set is gone, they won’t grow another, so old elephants can starve to death.

 

Elephant molars get a lot of wear. The elephant can replace them 5 times but not 6.

Praying mantis males take the prize for the most bizarre and macabre mode of programmed death.  After an elaborate mating ritual, the male fertilizes his mate’s eggs with his bottom half, while the female chomps off his top half.  Sometimes.

 

Octopuses makes an especially good story. They live a short time, a few months to a few years, depending on the species, and they die after reproducing once. After mating, the female guards and cares for her eggs, but if conditions are not right for her brood, she may eat them, and then she has another chance to try again later. Like praying mantisses, the octopus female sometimes cannibalizes the male. If she decides the time is right to deliver her young, not only does she refrain from eating her eggs, she stops eating altogether. The octopus mom guards her eggs from predators, focused and immobile for months on end.  (They are such smart animals, even playful.  How is it that they don’t get bored?)  During this time, her mouth seals over. She may live for years in this state of suspended animation, just guarding her eggs; but when the eggs hatch, she dies within a few days. Her death isn’t from starvation. We know because there are two endocrine glands, called “optic glands” though they are unrelated to the eyes, whose secretions control mating behaviour, maternal care, and death. The optic glands can be surgically removed, and the octopus mom lives longer. If just one optic gland is removed, the female doesn’t eat but still lives an extra six weeks. If both optic glands are removed, then the octopus doesn’t lose her mouth and resumes eating after the eggs hatch. She then regains strength and size and can live up to forty weeks more.

In 2007, Bruce Robison of the Monterey Bay Aquarium Research Institute discovered a deep-sea octopus mom watching over her clutch of 160 eggs in the deep, cold waters off the California coast. He returned periodically to observe the same octopus on the same rock in the same position. From 2007 to 2011, she didn’t eat, and she didn’t move except to slowly circulate the water over the eggs, assuring a fresh supply of mineral nutrients. After four and a half years, the eggs hatched, and the octopus mom disappeared, presumed dead, all within a few days. The empty eggshells were observed, memorializing her effort. It was the longest gestation ever observed.

 

Ageing in Reverse

In 1905, the Dutch biologist Friederich Stoppenbrink was studying the life cycles of Planaria, a kind of flatworm, a fraction of an inch long, common in freshwater ponds. He noted that when the animals didn’t have enough to eat, they systematically consumed themselves, beginning with the most expendable organs (sex), proceeding to the digestive system (not much use in a famine), and then muscles. The worms got smaller and smaller until the most precious part—the brain and nerve cells—were all that remained. Stoppenbrink reported that when he started to feed the worms again, they grew back, rapidly regenerating everything they had lost. What’s more, they looked and acted like young worms, and when their cohorts who had not been starved began to die of old age, the starved-and-regrown worms were still alive and kicking. This trick could be performed again and again. As long as Stoppenbrink kept starving and refeeding the worms, they went on living without apparent signs of age.

The medusoid Turritopsis nutricula achieved its fifteen minutes of fame when it was hailed as “the immortal jellyfish” in science news articles of 2010. The adult Turritopsis has inherited a neat trick: after spawning its polyps, it regresses back to a polyp, beginning its life anew. This is accomplished by turning adult cells back into stem cells, going against the usual developmental direction from stem cells to differentiated cells—in essence driving backward down a one-way developmental street. Headlines called Turritopsis the “Benjamin Button of the Sea.” Here again, life seems to imitate art.

Turritopsis can regress and begin life anew

 

Carrion beetles (Trogoderma glabrum) perform a similar trick, but only when starved. As they play life out on a carcass in the woods, the beetles go through six different larval stages in succession, looking like a grub, and then a millipede, and then a water glider before ending up as a six-legged beetle. A pair of entomologists working at the University of Wisconsin in 1972 isolated the sixth-stage larvae (when they were just ready to become adults) in test tubes and discovered that without food, they regressed to stage-five larvae. If they were deprived of food for many days, they would actually shrink and regress backward through the stages until they looked like newly hatched maggots. Then, if feeding was resumed, they would go forward again through the developmental stages and become adults with normal life spans. They found they were able to repeat the cycle over and over again, allowing them to grow to stage six and then starving them back down to stage one, thereby extending their life spans from eight weeks to more than two years.

Carrion beetle, when starved, reverts to any of its previous larval stages.

Continuous Regeneration

Hydras are radially symmetrical invertebrates, each with a mouth on a stalk, surrounded by tentacles, which grow back when cut off—like the many-headed monster of Greek mythology for which they are named. With their tentacles, they snare “water fleas” and other tiny crustaceans, on which they feed. Some hydras are green, fed by symbiotic algae living beneath their translucent skin.Hydras have been studied for four years at a time, starting with specimens of various ages collected in the wild, and they don’t seem to die on their own or to become more vulnerable to predators or disease. In the human body, certain cells, such as blood cells, skin, and those of the stomach lining, slough off and regenerate continuously. The hydra’s whole body is like this, regenerating itself from stem cell bedrock every few days. Some cells slough off and die; others, when large enough, grow into hydra clones that bud from the stalk-body to strike out on their own. This is an ancient style of reproduction, making do without sex. For the hydra, sex is optional—an occasional indulgence.

One recent article claims that the hydra does indeed grow older, and it shows it by slowing its rate of cloning. The author suggests that perhaps clones inherit their parents’ age. The hypothesis is that only sexual reproduction resets the ageing clock. If this is true, then the hydra’s style of ageing is a throwback to protists, ancestral microbes more complex than bacteria. Amoebas and microbes of the genus Paramecium are examples of these protists, single cells in a vast lineage that has anciently radiated into over one hundred thousand species and includes all the seaweeds, slime moulds, and ciliates and other organisms that do not belong to the animal, fungal, plant, or bacteria kingdoms.

 

Ancient Aging

For paramecium, sex and reproduction are two entirely different functions.  Reproduction takes place by simple mitosis—the cell clones itself. Sex takes place by “conjugation”.  The paramecium sidles up to another paramecium, their two cells merge and then the two cell nuclei merge, mixing their DNA, reshuffling within each chromosome, as genes cross over from one to the other.  Then the two cells separate, but the two cells that come apart are not the two cells that entered.  Each one is a different combination of the two original cells—“half me and half you.”

Here is the connection to aging:  Cells keep track of how many times they have cloned themselves via telomere length.  Each time the cell clones itself, the telomeres becomes a little shorter.  When it becomes too short, the cell languishes and dies.  The telomere can be re-set to full length with the enzyme telomerase, but this only happens during conjugation, not during mitosis.  The result of withholding telomerase is that the individual can clone itself about a hundred times, but at some point, it must share its genes via conjugation, giving up its individual identity.  Telomere shortening is an ancient mode of aging that forces the individual to share genes with the community.

This ancient process was a template for the future evolution of aging. Many higher organisms have telomeres that shorten through our lifetimes, until we die. Telomerase is held back in humans, dogs and horses, but not pigs, mice or cows. In the former animals, telomeres are only reset during reproduction, when a new individual is formed from gamete cells of two different parents.  Just like paramecia.

 

Bees That Can Turn Ageing Off

Queen bees and worker bees have the same genes but very different life spans. In the case of the queen bee, royal jelly switches off ageing. When a new hive begins, nurse bees select—arbitrarily so far as we can tell—one larva to be feted with the liquid diet of royalty. Some physiologically active chemical ambrosia in the royal jelly triggers the lucky bee to grow into a queen instead of a worker. The royal jelly confers upon the queen the overdeveloped gonads that give her a distinctive size and shape. The queen makes one flight at the beginning of her career, during which she might mate with a dozen different drones, storing their sperm for years to come.

Weighted down with eggs and too heavy to fly, the full-grown queen becomes a reproducing machine: she lays at a prodigious rate of about two thousand per day, more than her entire body weight. Of course, such reproductive regality requires a suite of specialized workers to feed her, remove her waste, and transmit her pheromones (chemical signals) to the rest of the hive.

Worker bees live but a few weeks and then die of old age. And they don’t just wear out from broken body parts, the rough-and-tumble worlds through which they fly. We know this because their survival follows a familiar mathematical form, called the Gompertz Curve, which is a well-known signature of biological aging. Meanwhile, queen bees, though their genes are identical to those of the workers, show no symptoms of senescence. They can live and lay for years and sometimes, if the hive is healthy and stable, for decades. They are ageless wonders. The queen dies only after running out of the sperm she received during her nuptial flight. At that point, she may continue to lay eggs, but they come out unfertilized and can only grow into stingless drones. Then, the same workers that formerly attended her assassinate the depleted queen. They swarm about her, stinging her to death.

What does it all mean?

Styles and durations of aging in nature are just about as diverse as they can be.  Aging doesn’t have to exist at all, and individual fitness would be 20-30% higher in most cases if aging just took a walk.  Where mother nature has tempered reproduction and kept aging in the life cycle, it is for the purpose of stabilizing the ecosystem, preventing population overshoot that can lead to extinction.  This theory accounts for some broad facts about aging in nature:

  • that aging is near universal in animals, but not necessarily in plants,
  • that aging slows down when animals are starved (no extra curtailment of life is needed in a famine)
  • that animals can substantially outlive their fertility
  • that predator lifetimes are generally longer than their prey
  • that the genetic basis for aging has been preserved over hundreds of millions of years

Apologia pro Scientia Sua

Were I, like Adam, choiced by evil snake
That fruit of knowledge I might free partake
Or, spurning insight, might forever be,
And dwell in vast, obscure eternity…

By two such options I’d be sorely torn—
’Twas not for blind submission I was born.
Infinity sans knowledge is no prize,
While light that fades to black before mine eyes
Is destiny no man would freely choose,
For what we have is all we have to lose.

Posed thus, ’tis plain: rebellion is my path—
I’ll risk the flaming ire of God’s own wrath,
His knowledge, freely giv’n is not so dear
As what by our own efforts we make clear.

With tools of science I’ll investigate
The logic of this world and mine own fate;
While passions I will equally devote
To quest for health, and death’s own antidote.

— Josh Mitteldorf

Detail from The Last Judgment by Hieronymus Bosch (1450-1516)