A multispecies ecology

...when we generate evolutionary explanations for why we behave the way we do, for why our bodies function as they do, we need to be cognizant of the possibility that other animals’ presence is shaping our selves.  We must think about the bodies and behaviors of other animals as core parts of the ecologies in which we exist and, thus, include them as part of the suite of central influences in our own evolution.  We did not make it in the world alone; we made it as part of a multispecies ecology...

-- Agustin Fuentes

Image: Charles Fréger

Vehicular selection

Birds in Nebraska have evolved shorter wings, which may help them avoid dying on roads by taking off quickly and darting away from cars.

-- report, paper.

Beyond syntax to semantics

...Ethologists who study animal behaviour increasingly accept the idea that fear keeps animals away from predators, lust draws them toward each other, panic motivates their social solidarity and care glues their parent-offspring bonds. Just like us, they have an inner life because it helps them navigate their outer life...

...After you spend time with wild animals in the primal ecosystem where our big brains first grew, you have to chuckle at the reigning view of the mind as a computer...Our rational mind is truly embodied, and without this emotional embodiment we have no preferences. In order for our minds to go beyond syntax to semantics, we need feelings. And our ancestral minds were rich in feelings before they were adept in computations...The brain that ‘feels’ precedes the brain that ‘thinks’...

-- Stephen T. Asma.

Asma's On Monsters is referenced in this post.

Xenotropia

A Tibetan mystic saying goes: We are here to realize the illusion of our separateness. The spiritual sentiment has a biological cognate. Our xenotropic drive — to merge with what is not us, temporarily in sex, or permanently in symbiosis or cross-species hybrids — is more than a metaphor. But it also offers spiritual solace. When we hook up with another, in sex or love (or, more rarely, both) we prove that our isolation is not permanent. In the fullness of time, we may all be linked...

-- from Death and Sex by (Tyler Volk and) Dorion Sagan quoted by Maria Popova

Beyond reality and imagination

The Book of Imaginary Beings is a compendium of extraordinary fictions of the human brain.

The Book of Barely Imagined Beings celebrates a few of the real creatures that are stranger and more astonishing than most of the ones that humans have imagined.

Nils Aall Barricelli was, perhaps, the first to explore another category altogether -- entities that are neither 'real' in the sense that most of us customarily use that term nor fictional -- when, in the early 1950s, he created numeric organisms based on Darwinian principles.

These organisms and the universes they inhabited existed purely as mathematical values. In Barricelli's mind, however, they were true organisms, not simply mathematical models of life.

Max Tegmark believes that physical existence and mathematical existence are the same, so any structure that exists mathematically is also real.

(see also Turing's Cathedral.)

Many real animals are stranger than imaginary ones

Nature allows every child to play tricks with her; every fool to have judgment upon her; thousands to walk stupidly over her and see nothing; and takes her pleasure and finds her account in them all.

-- Goethe 

The wealth of the soul exists in images. I speak in images. With nothing else can I express the words from the depths. 

-- attributed to Jung

This post relates to Rereading: The Book of Imaginary Beings online at The Guardian. Short descriptions of a few imaginary creatures which Borges never knew can be found here.

In an essay published in 1971 the physician Lewis Thomas argued that a bestiary for our time would have to be a microbestiary, featuring the likes of Myxotricha paradoxa, Blepharisma and plant-animal combinations that mostly exist in the sea. Their meaning, he suggested, would be "basically the same as the meaning of a medieval bestiary. There is a tendency for living things to join up, establish linkages, live inside each other, return to earlier arrangements, get along, wherever possible."

The Book of Barely Imagined Beings was partly inspired by Thomas's claim. I looked for real animals, stranger than imaginary ones, that could help me better understand the nature of being and beings. 

See also Nature Beyond Our Wildest Imaginings.

images: the Ornate Ghost Pipefish, Solenostomus paradoxus, and the Rosey-lipped batfish, Ogcocephalus darwini.

The creature from the black puddle

The Creature from the Black Lagoon

The eggs, nestled in a protective jelly stained golden by tannins that glistened in the light, might have looked like any other clutch of salamander eggs from a woodland pond. But they weren’t, and this was no pristine sylvan pool. It was a roadside puddle, and those eggs promised to contain something unsettling. If Brady was right, the toxic brew associated with road run-off had forced the spotted salamanders to evolve in the space of decades. In the time since Neil Armstrong first set foot on the moon in 1969, these animals had been reinvented by nature to cope with life on the road.

--from Unnatural Selection by Emily Monosson, published by Aeon magazine.

Persistent sub-lethal exposure to toxic chemicals is enough to drive evolution in salamanders and other creatures. From this, other thoughts follow:

Is it possible that the genomes of vertebrate populations are not as recalcitrant to change as we once thought? What if they harbour subtle genetic variants, like ghosts from environmental challenges past, offering a degree of flexibility in the face of change? Perhaps...[the] salamanders are harbingers of discoveries to come. It might even be that rapid evolution in response to toxic chemicals is quite common. A further...question suggests itself. If life can adapt, why bother with expensive environmental cleanup? Why not let nature take its course?

The answer is "both intriguing and deeply troubling":

Industrial chemicals might have effects that are widespread and heritable, yet also maladaptive, not only in humans but in all life on earth...

We certainly have not escaped the chemical gauntlet. We might yet experience a far more insidious kind of rapid evolution through chemically induced epigenetic alterations. How these will influence the evolution of human populations is anybody’s guess. Perhaps they will be of little consequence...[or] perhaps humans in the not-so-distant future will become unwitting actors in a real-life science fiction, fending off hoards of fecund, rapidly evolving chemical-resistant pathogens and insects even as we are weakened through the accumulation of myriad changes of our own making.

Just visiting

The recognition of these hazards may help us understand deeper mysteries about Life in the Universe. Many explanations have been offered as to why we find no evidence for the existence of advanced extraterrestrial life in the nearby Universe.  Perhaps we are too uninteresting to be worth contacting; perhaps life requires extremely improbable events to sustain it. More likely, I feel, is that life never survives for long periods. Asteroidal impacts, passing comets, bursts of gamma radiation, all these external hazards are common occurrences. We are shielded from many of them by the planet Jupiter and our large Moon. Without these gravitational shields we would have suffered a string of catastrophic impacts that would have continually reset the evolutionary clock. Couple with the threat to life offered by internal hazards like war, disease and environmental disaster, we begin to see that it is perhaps not entirely surprising that no one is 'out there' in our part of the Universe. The cosmic environment stretches far wider than Darwin ever imagined.

-- from 'Cosmic Environmentalism' in The Artful Universe (Expanded) by John Barrow

Transformations

I'm rereading The Origin and, geekishly, really enjoying this sort of thing (from Morphology, Chapter XIV):

Most physiologists believe that the bones of the skull are homologous with — that is, correspond in number and in relative connexion with—the elemental parts of a certain number of vertebræ. The anterior and posterior limbs in all the members of the vertebrate classes are plainly homologous. So it is with the wonderfully complex jaws and legs of crustaceans. It is familiar to almost every one, that in a flower the relative position of the sepals, petals, stamens, and pistils, as well as their intimate structure, are intelligible on the view that they consist of metamorphosed leaves, arranged in a spire. In monstrous plants, we often get direct evidence of the possibility of one organ being transformed into another; and we can actually see in flowers during their early development, as well as in crustaceans and many other animals during their embryonic states, that organs, which when mature become extremely different, are at an early stage of growth exactly alike.

Darwin asks questions such as: 'Why should the brain be enclosed in a box composed of such numerous and such extraordinarily shaped pieces of bone?' And then shows how natural selection is the necessary explanation.

Viruses like bees

Viruses, instead of being single-minded agents of disease and death, now begin to look more like mobile genes. Evolution is still an infinitely long and tedious biologic game, with only the winners staying at the table, but the rules are beginning to look more flexible. We live in a dancing matrix of viruses; they dart, rather like bees, from organism to organism, from plant to insect to mammal to me and back again, and into the sea, tugging along pieces of this genome, strings of genes from that, transplanting grafts of DNA, passing around heredity as though at a great party. They may be a mechanism for keeping new, mutant kinds of DNA in the widest circulation among us. If this is true, the odd virus disease, on which we must focus so much of our attention in medicine, may be looked on as an accident, something dropped.

-- from Lives of a Cell by Lewis Thomas (1971)

Endless transformations

Another example of the almost unimaginable potential of evolution:

Both the TRPA1 and TRPV1 genes are hundreds of millions of years old, having arisen deep in evolutionary history, while vampire bats, pit vipers, and pythons and boas are much younger species. The histories of these genes and animals, and the repeated invention of infrared sensing, demonstrate how the evolution of new abilities does not necessarily require new genes, but new variations of very old genes and new ways of using them.

-- Sean B. Carroll

The body electric

cells are powered not by chemical reactions, but by a kind of electricity, specifically by a difference in the concentration of protons (the charged nuclei of hydrogen atoms) across a membrane. Because protons have a positive charge, the concentration difference produces an electrical potential difference between the two sides of the membrane of about 150 millivolts. It might not sound like much, but because it operates over only 5 millionths of a millimetre, the field strength over that tiny distance is enormous, around 30 million volts per metre. That's equivalent to a bolt of lightning.

...this [is] electrical [the] driving force the proton-motive force. It sounds like a term from Star Wars, and that's not inappropriate. Essentially, all cells are powered by a force field as universal to life on Earth as the genetic code. This tremendous electrical potential can be tapped directly, to drive the motion of flagella, for instance, or harnessed to make the energy-rich fuel ATP.

However, the way in which this force field is generated and tapped is extremely complex. The enzyme that makes ATP is a rotating motor powered by the inward flow of protons. Another protein that helps to generate the membrane potential, NADH dehydrogenase, is like a steam engine, with a moving piston for pumping out protons.

-- from Life: is it inevitable or just a fluke? in which Nick Lane once again champions the hypothesis that the proton gradient at deep sea alkaline vents drove the origin of life on Earth.  'Far from being some mysterious exception to the second law of thermodynamics...life is in fact driven by it.'

Lane argues that similar circumstances would necessarily hold on other planets, but that the jump to eukaryotic cells is likely to be vastly rarer.

Cellular origins in a viral world

The discovery of an unusual hybrid virus living in one of the harshest environments on the planet suggests a solution to the conundrum of how RNA-based life 'updgraded' to DNA-based life. More

P.S. A good phrase: "It's a mythological beast of a virus, but it actually exists.”

'The pillars of morality...

...are reciprocity (fairness) and empathy (compassion).'

There is little new in this presentation if you're already familiar with Frans de Waal's work but it's a nice introduction if you're not:

Men, in spite of all their morality, would never have been better than monsters, if nature had not given them pity to assist reason. Indeed, what is generosity, what clemency, what humanity, but pity applied to the weak, to the guilty, or to the human species in general?...It is this pity which hurries us without reflection to the assistance of those we see in distress; it is this pity which, in a state of nature, stands for laws, for manners, for virtue, with this advantage, that no one is tempted to disobey her sweet and gentle voice.

-- from On the Inequality of Man by Jean-Jacques Rousseau (and quoted by Timoth Pachirat in Every Twelve Seconds)

Lots of rats and pigeons

...aka 'disaster taxa' in the wake of our current mass exintinction:

Ultimately...life will recover: it always has. The mass extinctions of the past offer hints as to how the ecosystem will eventually bounce back, says Mike Benton at the University of Bristol, UK. The two that we know most about are the end-Permian extinction 252 million years ago, which wiped out 80 per cent of species, and the less severe end-Cretaceous extinction 65 million years ago, which famously took out the dinosaurs. The Permian extinction is more relevant because it was caused by massive global warming, but Benton cautions that the world was very different then, so today's mass extinction will not play out in quite the same way.

Recoveries usually have two stages. If ours pans out in the same way, the first 2 to 3 million years will be dominated by fast-reproducing, short-lived "disaster taxa". These will rapidly give rise to new species and bring the world's species count back up

-- from Will there be any Nature Left?, part of a package on the Deep Future. I'd say the future is likely to be less predictable, especially given the human tendency to meddle and manipulate.

Animat

Though experiments probing the information structure of the human brain are still in their early stages, mathematical simulations have shown that integrated information can in fact be measured in other systems. Tononi and his colleagues devised a system so simple that its phi [a measure of integrated information] can be calculated — a simulated animal called an animat. Relying on sensors that detected the environment, actuators that allowed it to move and places to store data as it learned, this animat worked its way through a computer maze. The animat also possessed an ability that most living organisms take for granted: It could gradually evolve over 50,000 generations of maze running.

At the start, the animat had a hard time navigating. But around generation 14,000, it got good. Along with this performance boost, the animat’s phi, the amount of information successfully shuttled among its constituent parts, went up. Different bits learned to communicate. By generation 49,000, the animat whizzed through the maze with its high phi.

-- report, paper.

The fish in the sea

A study suggests that most fish in the oceans today are descended from freshwater species. One possible implication of this, notes a report is that:

it is possible that seas may be more prone to extinctions than land, rivers or lakes; while rivers and lakes form an "arc of survival" that can reseed the oceans when marine species are lost. 

"I don't think our results show that seas are strongly inhospitable, but they may become so at certain points in time," [says study co-author John Wiens]. Unfortunately, the strong ocean acidification that is predicted for the near future means we may be heading for one of those times now, he adds. 

Today, however, rivers and lakes may not be healthy enough to help re-supply the oceans...

'Libertine bubbles'

Ain't nobody here but us Scyllarides latus larvae

Stranger and more plausible than the theory (attributed to Aristophanes in the Symposium) that sex has its origins in people chasing around trying to find the other half from which they were once severed is the libertine bubble theory of Thierry Lodé, which argues that rather than providing reproductive advantages:

it might be better to see sex as a genetic exchange between two organisms, as originating from an archaic horizontal gene transfer process among the prebiotic bubbles on the ocean surface, which are thought to have played a major role in the creation of living cells. My theory suggests sex results from three key primitive conditions: first, bubbles form spontaneously, creating a favourable environment for genetic material; second, the "promiscuous" nature of these bubbles allows transfer of genetic material among the most "libertine" of the bubbles, gradually leading to a certain membrane selectivity; and third, DNA overcrowding encourages primitive meiotic recombination.

Metamorphosis: bifurcated being

The larva of Luidia sarsi is a semi-transparent diaphanous sprite that feeds on algae and grows to a remarkable 4 centimetres. Then something extraordinary happens. Instead of changing shape to become an adult, a cluster of cells lining the larva's internal cavity grows, like an alien invader, and out of these a starfish is born. Floating free from its other self, the adult form settles on the ocean floor, where it survives and grows by hunting down other starfish in the dark of night. Meanwhile, the larva continues its vegetarian existence, grazing the surface waters above.

-- from Evolution's freak factory, in which Frank Ryan suggests hybridisation played a role in Cambrian explosion.

See also: Hybrids, chimeras, trees and webs

P.S. In a highly critical review of Ryan's book Metamorphosis, Josh Trapani says that Ryan champions the views of Donald Williamson who postlated that interbreeding occurs between not just different species but different phuyla; for example, between ascidians (sea squirts) and echinoderms (sea urchins):

He postulates that this has happened repeatedly between different groups of widely divergent organisms. Moreover, he postulates that the hybrids look like one parental species as larvae and like the other as adults, rather than simply exhibiting a mix of characteristics, as most hybrids do. Not only is this hypothesis not supported by evidence, but plenty of evidence, including powerful molecular evidence, directly contradicts it.

An eight-branched spiral

Eoandromeda octobrachiata may or may not set the tree of life wobbling but it has certainly been given a beautiful name, inspired by the fact that its body plan resembles the spiral galaxy Andromeda.