Xenophyophore

Thirty-fourth in a series of notes and comments on The Book of Barely Imagined Beings

Chapter 25: Xenophyophore

page 342: Titan. See for example this report from NASA/JPL. Another candidate is Enceladus. Mars remains an enigma.

page 342: single-celled organisms. Charles Taylor says that it is not entirely appropriate to label Xenophyphores in this way. "Rather, [they] have a coenocytic or hyphal organisation, with numerous nuclei scattered throughout long branching cytoplasmic tubes."

page 344: Dali painting. The artist Rona Lee is among those who want to transform our feelings for the bottom of the sea. Neptune Canada has a Flickr stream of deep sea beasties.

page 346: Evidence for bilaterians dates back some 585 million years.

page 347: Rock is not the opposite of life but its essential partner. See, for example, a blog such as Written in the Rocks.

page 349: all stories originat[e] from a marvelous stone. In The Aleph by Jorge Luis Borges, it is reported that "the Faithful who gather at the mosque of Amr, in Cairo, are acquainted with the fact that the entire universe lies inside one of the stone pillars that ring its central court." For an attempt at an explanation based in evolutionary theory see Brian Boyd's On the Origin of Stories.

page 350: perhaps consciousness is the least mysterious thing...and it is matter itself that is truly astonishing. “It is not how things are in the world that is mystical, but that it exists,” wrote Ludwig Wittgenstein. (Here is a note on consciousness and here's something on dreaming and reality.) 'It from bit', wrote John Archibald Wheeler. But what is 'bit'? James Gleick quotes Wheeler as follows:

“Deplore? No celebrate the absence of a clean clear definition of the term 'bit' as an elementary unit in the establishment of meaning...If and when we learn how to combine bits of fantastically large numbers to obtain what we call existence, we will know better what we mean by both bit and by existence.” This is the challenge that remains, and not just for scientists: the establishment of meaning.

Recent experiments suggest there is a way to go:

[Perhaps] 'particle' and 'wave' are concepts we latch on to because they seem to correspond to guises of matter in our familiar, classical world. But attempting to describe true quantum reality with these or any other black-or-white concepts is an enterprise doomed to failure.

It's a notion that takes us straight back into Plato's cave, says Radu Ionicioiu. In the... allegory, prisoners shackled in a cave see only shadows of objects cast onto a cave wall, never the object itself. A cylinder, for example, might be seen as a rectangle or a circle, or anything in between. Something similar is happening with the basic building blocks of reality. "Sometimes the photon looks like a wave, sometimes like a particle, or like anything in between," says Ionicioiu. In reality, though, it is none of these things. What it is, though, we do not have the words or the concepts to express.

Multitudes

The Foraminifera Sculpture Park in Guangzhou Province officially opened this month and is dedicated to large sculptures of these single-cell marine organisms. Marine geologist Bilal Haq of the National Science Foundation got the idea of a sculpture park a decade ago after seeing palm-sized models of foraminifera in the lab of marine biologist Zheng Shouyi at the Institute of Oceanology in Qingdao, China. Zheng persuaded local authorities to pursue the idea. The 114 sculptures were carved out of marble, granite, and sandstone.

-- a random sample in Science.

D'Arcy Thompson wrote of the Foraminifera:

In few other groups, perhaps only among the Radiolaria, do we seem to possess so nearly complete a picture of all the possible transitions between form and form, and of the whole branching system of the evolutionary tree: as though little or nothing of it had ever perished, and whole web of life, past and present, were as complete as ever.

He adds:

in days gone by I used to see the beach of a little Connemara bay bestrewn with millions upon millions of foraminiferal shells, simple Lagenae, less simple Nodosariae, more complex Rotiliae: all drifted by wave and gentle current from their sea-cradle to their sandy grave: all lying bleached and dead: one more delicate than another, but all (or vast multitudes of them) perfect and unbroken.

Image: Micropolitan

Beings animalculous (2)

My ignorance is infinite and until yesterday I knew nothing about Heliozoa, or Sun Animalcules. This is Actinosphaerium eichhorni:


(Photo Wim van Egmond, Micropolitan Museum)

P.S. 14 Dec: Skeptic Wonder features protist-centred blogging.

Parasite rex

When you look at normal rats, and expose them to cat urine, cat pheromones, exactly as you would expect, they have a stress response: their stress hormone levels go up, and they activate this classical fear circuitry in the brain. Now you take [Toxoplasmosis]-infected rats, right around the time when they start liking the smell of cat urine, you expose them to cat pheromones, and you don't see the stress hormone release. What you see is that the fear circuit doesn't activate normally, and instead the sexual arousal activates some. In other words, Toxo knows how to hijack the sexual reward pathway. And you get males infected with Toxo and expose them to a lot of the cat pheromones, and their testes get bigger. Somehow, this damn parasite knows how to make cat urine smell sexually arousing to rodents, and they go and check it out. Totally amazing...

...On a certain level, this is a protozoan parasite that knows more about the neurobiology of anxiety and fear than 25,000 neuroscientists standing on each other's shoulders, and this is not a rare pattern.

-- Robert Sapolsky.

Beings animalculous

I have been searching for some time for this picture:

Monster Soup by William Heath (1795 - 1840)

Heath, satirizing the appalling production of London water companies in the 1820s or 30s (?), uses a line from Milton in jest:

Gorgons and Hydra’s, and Chimera’s dire.

It's from Book 2 of Paradise Lost. The original context is splendid:

...through many a dark and drearie Vaile
They pass’d, and many a Region dolorous,
O’re many a Frozen, many a Fierie Alpe,
Rocks, Caves, Lakes, Fens, Bogs, Dens, and shades of death,
A Universe of death, which God by curse
Created evil, for evil only good,
Where all life dies, death lives, and nature breeds,
Perverse, all monstrous, all prodigious things,
Abominable, inutterable, and worse
Then Fables yet have feign’d, or fear conceiv’d,
Gorgons and Hydra’s, and Chimera’s dire.

Nature's smartdust

Communication, decision making, 'city living', accelerated mutation, navigation, learning and memory.

-- Six reasons 'why microbes are smarter than you thought.'

Remarkable though these behaviours are, we have probably only scratched the surface of what single-celled organisms can do. With so many still entirely unknown to science, there must be plenty more surprises in store.

Stentor

Dancing

New Scientist reports that 'dancing' Volvox algae can 'waltz' and 'minuet'. [1]



It's another reminder that while green, red and brown algae are often called 'plants', some of them have properties that are almost 'animal'-like. [2] Some dinoflagellates, for example, have simple eyes to hunt for food. [3]

And at a macro scale, kelp (which are brown algae) do remarkable things, as Charles Darwin saw:

The number of living creatures of all Orders, whose existence intimately depends on the kelp is wonderful.

A great volume might be written, describing the inhabitants of one of these beds of seaweed….I can only compare these great aquatic forests of the southern hemisphere, with the terrestrial ones in the inter-tropical regions. Yet if in any country a forest was destroyed, I do not believe nearly so many species of animals would perish as would from here, from the destruction of the kelp. [4]

[1] Dancing Volvox: Hydrodynamic Bound States of Swimming Algae by Knut Drescher, Kyriacos C. Leptos, Idan Tuval, Takuji Ishikawa, Timothy J. Pedley and Raymond E. Goldstein (pdf).

[2] Other 'simple' protists such as forams display remarkable properties too. Lynn Margulis is a microbiological William Blake in her vision of these creatures:

Large single-celled forams choose from brightly colored sand grains the correct ones with which to make shells. Aware of shape and color, they make choices and reproduce their kind. Awareness in some form has been naturally selected for at least 550 million years. For me, our spirituality and moral nature help perpetuate our living communities, just as similar attributes aided previous living communities whose evolution is chronicled in the fossil record.

[3] "By most definitions...the planktonic dinoflagellate, Erythropsidium, must have among the smallest of eyes, since the creature is only 50–70 μm in diameter." -- from You are what you eat by I R Shwab. Others with eyes include: Peridinium foliaceum and P. balticum. See Ultrastructure of Microalgae: nonphotosynthetic plastids.

[4] The Voyage of Beagle, Chapter 11:

Almost all the leaves, excepting those that float on the surface, are so thickly incrusted with corallines as to be of a white colour. We find exquisitely delicate structures, some inhabited by simple hydra-like polypi, others by more organised kinds, and beautiful compound Ascidiæ. On the leaves, also, various patelliform shells, Trochi, uncovered molluscs, and some bivalves are attached. Innumerable crustacea frequent every part of the plant. On shaking the great entangled roots, a pile of small fish, shells, cuttlefish, crabs of all orders, sea-eggs, starfish, beautiful Holothuriæ, Planariæ, and crawling nereidous animals of a multitude of forms, all fall out together. Often as I recurred to a branch of the kelp, I never failed to discover animals of new and curious structures.

Darwin was writing about kelp in cool southern waters. But kelp 'forests' have recently been discovered in deep tropical waters too. It's thought that these may act as refugia under some conditions of climate change.

More than slime

We were looking for pretty animals that have eyes, are coloured, or glow in the dark; instead, the most interesting find was the organism that was blind, brainless, and completely covered in mud.

-- says Mikhail "Misha" Matz, who thinks the giant protists' bubble-like structure is probably one of the planet's oldest body designs, and may have existed for 1.8 billion years. (BBC report here. Richard Dawkins posts a Discovery report here )

These beings, which have 'a number of openings all over the body act as mouths and outlets for waste', are about 3cm across. Their cousins [?] the Xenophyophores, can be 20cm across.

P.S. 2 Dec: NYT

A bearer of foreign bodies

The Book of Barely Imagined Beings was having trouble with beings beginning with X until Tom Goreau suggested the xenophyophores, giant single celled organisms that build structures from their own excrement.

Most of these rarely discussed and poorly understood organisms, including Syringammina fragilissima live on the seabed; but at least one species, Occultammina profunda, is infaunal, burying itself in the sediment.

Earlier this month Zoltan Sylvester, a skeptical geologist, blogged on trace fossils called graphoglyptids that may encode the tracks left by Paleodictyon, an ancient infaunal xenophyophore. These are almost perfect honeycomb-like hexagonal patterns:


The patterns are so striking, he says, that it wouldn't be surprising if the uninformed were to seize on them as 'crop circles of the deep sea'. But the most widely accepted idea in the scientific community is that they are 'farming traces':

In other words, these guys (whatever they might be, nobody really knows) create well aerated open burrow systems a few millimeters below the sea floor, with multiple openings to the sediment surface, so that chemosynthetic bacteria move in to get the necessary oxygen to oxidize methane and hydrogen sulphide, their favorite food.

Through idle free-association a long way from science, xenophyphores put me in mind of the Dowager Empress, driven (in W G Sebald's account) to absorb all, so obsessed by death that she swallowed powdered pearl every morning as an elixir of invulnerability, and stifled her empire by trying to hold all still. But the association is vague and the differences are huge. Not least, Xenophyophores thrive abundantly while the Empress died of dysentery after eating a double helping of her favourite crab apple with clotted cream pudding.