It’s been a while since Ultraphyte blogged on biological sex. Since Brain Plague in 2000, I’ve felt there was little more to be said on the postgender world. However, trust the cell biologists to reveal twists even more bizarre than science fiction.
For perspective: Back in the sixties, we were taught that people came in two sexes and four crayon colors (brown, red, yellow, white). Now we know that sexes, like colors, are a spectrum, like infrared through visible and UV. Some examples, in this open-access Nature review:
- People are mosaic–perhaps 1% of us. Mosaic means we have large chunks of cells with a chromosome count different from other chunks of cells. So, maybe, your womb is female (XX) but your legs are male (XY). Or your testes are male (fathering children), then your surgeon “discovers” a womb tucked behind.
How can this happen? Several ways, each more bizarre than the last:
- Cell divisions in the early embryo make a mistake called “non-disjunction”; that is, at mitosis, chromosomes replicate but both copies go over to one daughter. So, for instance, YX –> YY XX –> daughter cells Y and YXX instead of YX, YX. The Y cell dies; but the YXX can recover by spitting out the Y, leaving XX. Now, a part of the body continues developing YX (the original cell line) whereas the others go XX.
- A pair of fraternal twins (XY and XX) start out on their own, but then stick together and “merge” into one body. Now you genetically consist of two different people, with two different chromosome sets.
- Your autosomes (all the chromosomes other than X or Y) carry other sex-regulating genes–dozens of them. Any one of them can go missing at cell division, leaving you with some other kind of mosaic, say a male body that “ignores” the screaming male hormone. You end up a super beautiful female (outside) without functional reproductive organs.
It gets weirder. When you’re pregnant, what becomes of all those fetal cells that wind up in your own blood stream–enough for a blood test that precisely details your child’s sex and any genetic defects? Virtually 100% of mothers are mosaic with their children’s cells.
Some of those fetal cells wind up part of your tissue, even entering your brain and hooking up with your own neurons. So, decades later, you still have your child’s cells forming part of your brain. Your child, too, has some of the mother’s cells. So, a mother and a male child each share part of each other, including each other’s gender.
Where this all leads, we don’t yet know, but here’s a valentine for someone who knows why.
You will recall from our Antarctic Upside Down Lakes that we came across some amazing alien life forms emerging out of five meters of ice, from another fifteen meters or more in the lake below. Our expedition was led by Rachael Morgan-Kiss, at Miami U-Ohio, sponsored by NSF–her research blog is here.
These life forms are cyanobacterial mats–dessicated cyanobacteria (photosynthetic microbes) entwined with algae, protists, even possibly tiny invertebrates like water bears. At a touch, they fall apart and blow off in the wind, to find a melting hole in the lake, or in another lake downwind. Well, some of this one didn’t blow away–it ended up stuffed into the purple capped tube, and shipped at -20C to our home continent.
Here’s what one of the samples looked like, arriving back at Kenyon. Still a bit of green.
Is anything alive in there? To find out, we put samples into BG-11 cyanobacterial growth medium, a mixture of plain salts such as carbonate, nitrate, and phosphate–essential atoms, little more, since cyanobacteria build just about everything from scratch. Professor Chris Bickford kindly loaned his lighted incubator, which went down to 10C (50F). That’s not especially cold, but it’s the coldest our incubator will go. And actually, this temperature is reached within the depth of some of the Dry Valley lakes, as well as in sun-heated pools of meltwater during the Antarctic summer.
The samples from Lake Fryxell we put into 100-ml graduated cylinders, to give them both a surface for green algae and a depth for growth of the orange-brown ones.
After two weeks–It’s alive! Green stuff bubbling oxygen. Remember–that’s where all the oxygen you breathe comes from.
After two weeks, you can see the glacier-melt brown stuff’s grown too, expanded and bubbling, while yellow stuff multiplies throughout the flask. We think the yellow stuff includes heterotrophs (organic food eaters) that suck up the oxygen, which is toxic to the photosynthesizers.
Meanwhile, what to call all this stuff? Today, it’s all in the DNA. So we took some of the original samples to smash them up for their DNA.
Here are samples of Fryxell mat (colored) and glacier mat (dark) ready for the PowerBiofilm bead beater: Tubes of sharp glass beads to shake in the vortexer.
So what’s in the DNA? Stay tuned, and let’s find out.
This week, geologist Nora Noffke reports a study of Curiosity rover images that resemble Earth’s life forms. Noffke has long experience of interpreting fossils of ancient Earth in three billion-year-old rock formations such as Pilbara, Australia. In other words, writing grants persuading us to fund one’s camping in of Earth’s most scenic places.
The diagram above shows just one of her many images, with interpretation (the scale bar is 15 cm). It certainly looks like a modern microbial mat upon lake sediment, peeled back and rolled over in some places. Only organic life forms produce such flexible sheets of material, in layers associated with water (whose existence on Mars has also gained evidence). Surprisingly, perhaps, we have no statistical test to say, “that’s a microbial mat.” But the quality and quantity of the images may be our most compelling yet found.
Perhaps Noffke’s most convincing argument is that, were these rocks terrestrial, they would undoubtedly be accepted as fossils of ancient life. To be consistent: Either life existed on Mars three billion years ago–or it failed to exist on Earth.
Why is it so hard to find life on Mars? Microbial life can be incredibly subtle. I came to realize this during my explorations of Antarctica–arguably the best modern model for life without macrobiota.
The Antarctic Dry Valleys are a landscape in which all life is microscopic–that is, microbial or tiny invertebrates requiring magnification to see. There is no soil–because “soil” is a product of living bodies, plant detritus chopped by arthropods and processed by worms, feces of larger life. No soil, only sand and pebbles.
But here and there–where there is water–the microbes congregate in forms called mats or biofilms. Seeing these biofilms can be tricky.
In this example, I have outlined the bit of “stream mat” so you can see it. To find it, I noticed (after hours of hiking the sand) a sort of pasty trail, a few inches wide, descending from a glacier. The glacier had melted previously, sending a trickle of melt water down to the valley. Where the stream flowed, cyanobacteria had photosynthesized like crazy, growing a mat in the stream. Once the stream dried up, the mat dried too–you can see the pebbles trapped in it. This summer, if the mat gets lucky, the glacier will melt again, and water will ooze once more down the mat. If not, the mat will dry and crack–and the wind might carry it to a nearby lake, where the edge melts in.
If the cyanobacteria end up in a lake, what grows there?
At the bottom of the lake, with barely a few photons to capture, the mats grow into amazing castles. (See Kay Vopel and Ian Hawes). Their cells make oxygen bubbles that ultimately lift bits of mat up to the ice, where the wind continually scrapes ice away, and eventually the mat bits surface–again to blow off to other lakes.
Who knows if such a mat cycle once happened on Mars? If it did, finding it would be quite a trick today.
Recall the mitochondrial singularity–my hypothesis that not only did the singularity already happen, we are evolving into the mitochondria of our own machines? And, like mitochondria, we don’t even notice. From the mitochondrion’s point of view, the organelle just gives up on activities that its host cell performs for it. Welcome to our posthuman future (or transhuman, if you prefer.) People who like the idea call it transhuman, whereas those who fear it cry, “Posthuman!”
So I’ve inaugurated a new feature–a review of this year’s less noticed stories of transhuman improvement. This year’s winner, more bizarre than most, is:
Robot camel jockeys. In the Persian Gulf, where camel racing is a time-honored sport, children as jockeys have been replaced by robots. The robots transmit commands from the masters, hovering nearby in cars. One wonders when the camels–and their masters–will be replaced as well.
Perhaps closer to home, with more urgent significance:
Ebola disposal robots. Disposal of contaminated clothes is the most dangerous part of tending Ebola patients. So why not let robots do the job of removing Ebola-contaminated garments? As we know, robots already serve other health care needs, such as calming dementia patients.
In another realm, our bid for immortality via stem cells advanced this year along several startling fronts. Perhaps the most surprising achievement was the conversion of adult skin cells into primordial germ cells–embryonic-like cells of a type that could produce sperm and egg. Human sperm and egg in a culture dish?
Other stem cell achievements this year:
- Insulin from embryonic stem cells can cure diabetes.
- Stem cells cured a spinal injury, generating axons the length of the spinal cord.
- Blood vessel formation in a mouse brain, from bone marrow stem cells.
- 3D printing of stem cells may form replacement organs.
What’s your favorite transhuman advance of the year? Or posthuman horror?
Thanks to all my friends for keeping my spirits up, while I survived Antarctica, that “harsh and unforgiving continent.” At my return, my new Ultraphyte was here waiting, custom designed by Little Fingers Gifts. You can meet the new ultra with me in February, at Boskone.
Those cyano mats haven’t yet come home (still frozen at Crary Lab, I hope) but they’ve already swept into the plot of Blood Star Frontier. And my Antarctica blog has been updated with videos that were too large for the bandwidth. Any videos you missed, here’s the list.
Ivan the Terra Bus, known as the slowest bus on Earth, takes us from runway across the Ross ice shelf to McMurdo Station. Note the wooden interior panels, and the lack of shocks. From Midnight Sunglasses.
Helicopter view of McMurdo Station, Antarctica. Facing the mountains across the Ross Sea, the helo rises, turning toward the helipad, the Crary Lab (three white buildings connected by ramp), the blue dining hall with dorms, fuel storage tanks (round white things), windmills above Scott Road; then a brief view of volcano Mount Terror, heading out across Ross Sea. Mount Discovery appears, then the Royal Society Range (I think). Then a long stretch of sea ice, ending with a giant flat iceberg.
The helicopter sails across the Ross Sea to the Dry Valleys. Glaciers surge down between the hills, then we reach frozen Lake Bonney. The white stuff is like frozen foam–hard as glass, vicious if you fall. Our camp appears below: the Jamesway, then the lab (green box-like thing).
The Freudian exercise–drilling a hole through 5 meters of ice!
Mars on Earth: The scenery around frozen Lake Bonney (East Lobe).
Three-helicopter day; the day the one got stuck. You can see two of the three in this video.
Back at McMurdo, we tour the Pressure Ridges, where the sea ice meets land ice. Huge blocks thrust upward, and the holes attract seals–but we humans try to keep dry.
Off to a new lake, Lake Fryxell. Amazingly, each lake and surroundings have specific character. Around Fryxell, the sand shrinks into polygons, “patterned ground.” You can see it clearest at 1:30-1:50. In the lake, meanwhile, look at all those frozen castles, surrounded by the smoother blue ice that will melt forming the moat.
Every so often a seal or penguin gets lost, and for some reason heads up Taylor Valley. In my hikes I’ve come across a few seal vertebrae and skua bones. But here by Lake Fryxell, Renee from Lake Hoare shows off an exceptionally preserved specimen, perhaps a year old: the leopard seal.
Leopard seals are exceptionally aggressive predators. Solitary beasts, they are rare to find in the wild, let alone a stray one. They eat fish and penguins; look at those teeth. Their teeth can also lock together to strain water for krill.
The position of the dead seal shows that it died desperately pointing west up the valley, away from the sea about ten miles behind. You can see from this map where the seal was found (red arrow) and the direction to the sea (blue arrow).
Upon reflection, the seal offers scientists a cautionary tale. No matter how sure you are that you’re heading in the right direction, always listen carefully in case you’ve missed the point.
Well it’s time for Rachael’s science team to decamp to McMurdo, helos full of loot (microbial samples). The equipment is packed, the stove turned off. This will be another three-helicopter day. Meanwhile, I take a short hike to remember all the cool parts of this valley. The grooves of patterned ground.
A ventifact, a deeply windswept rock.
A volcanic rock full of bubbles.
The first helo shows up, an A-star with Shelley, a woman pilot. Way cool.
My clothes bags get packed into the side basket. Yes, it’s a bit unnerving.
All our boxes and samples got packed into #2, then the four of us rode home in an A-Star. The pilot offered to show us penguins on the edge of the Ross ice shelf. All our cameras came out, as the helicopter dipped close. They were too far for my camera, but we saw several colonies of Adelies and of Emperor penguins. The penguins waddled away, flapping flippers, just like an Attenborough documentary. A great end to our field season.
So where did all our samples and equipment go? Back to the Crary Research Laboratory.
The Crary lab has an unusual structure, for several reasons. Its primary function is to process field samples and ship them out. Researchers also conduct experiments on samples that cannot wait. But for our team, the main priority is to get our sample microbes home alive before the holiday “blackout” period. Note the helo staging area, conveniently situated downhill.
Crary has three “floors” but no elevator. From what I understand, McMurdo buildings have no elevators, because if they break down out here they could not soon be fixed. So Crary’s three “floors” are actually three distinct buildings, situated downhill; the higher numbers go lower. A long ramp connects all three floors. So you can wheel a cart full of gear easily all the way downhill, almost right to the helipad.
The third floor (downhill) is a wet lab where divers bring in their latest catch from the sea. The Ross Sea under the ice boasts an enormous variety of exotic fish and invertebrates. Often the invertebrates grow to unusual size, defying the expectations of divers trained in the tropics.
Some of the daily catch is brought to the Touch Tank, a tank of wildlife for exhibition and outreach. Here we see a sea lemon (slug-like invertebrate animal), anemones, and two starfishes feasting on a clam.
The Touch Tank is so-called because visitors are allowed to touch the creatures within. So of course I had to touch the sea lemon.
Who dives for these creatures? Mainly scientists studying the populations, physiology, and behavior of these amazing cold-adapted life forms. But this year, we also have a special grantee: Lily Simonson, resident artist. Lily dives herself to collect the organisms, which inspire the paintings that she creates on site in Crary.
So what’s up in Mactown since I’ve been gone? Surprisingly, quite a lot.
Neville the boiler inspector had his last day. He showed up at breakfast looking sad. We couldn’t bear to say goodbye, but Mike arranged an official certificate of appreciation. Then we heard tales of what happens over winter when someone hits the wrong button, and the whole station goes dark. The first thing you do is lock the door to keep out all the rubberneckers while you fix the problem. I must say, I’m glad it’s summer.
In the galley, we met Christine–the Christine of the viral Condition One clip on Youtube. The other half of the Year On Ice couple, Christine told us “Ants” Powell was out filming somewhere, I believe the South Pole. The Powells hope to film a television series here.
We heard that an ATV drove into the lake at Hoare, just outside the glacier where Rae told us the ice was thin. No one was hurt, but they got cold and wet, and a helo had to lift the ATV out.
A congressional delegation is showing up Tuesday (the day after I leave) including key House members who led the sequester last year that laid off several hundred Mactown employees. Obviously they waited till I leave before they dare show up here. In their honor, a “voluntary” carwash was called, to freshen up all Mactown’s motley collection of vehicles.
On Sunday I joined the 10 kilometer Scott Run. The temperature was 27 F, with no wind.
This evening, after “bag drop,” I’m looking forward to a lecture by Tyler Mackey on cyanobacterial mats and models of early life. Tyler is the one whose voice on the radio fills the valley each evening for check-in from Joyce camp: “Four souls are here, and we are all well.”
Only one thing left for me do here: Try out for the Antarctic Fire Department.
At the open house, the fire department showed off their vehicles. This unique fire truck has special tractor-tread multiple wheels, for driving across ice. It has been used to deal with vehicles engulfed in electrical fires.
I also got to use the equipment to lift a incapacitated person out of a narrow spot such as a crevice in the ice. They have this neat four-pulley system that enables you to lift someone out. Then I got drafted into a training exercise of firefighters going into a smoking building. There was real smoke, and I wore the whole gear, from boots and mask to oxygen unit. We had to climb up a staircase and crawl into three rooms looking for victims. We finally found the victim lying under a bed, and had to pull him out by the legs.
I must say, this last experience was the farthest thing from my mind when I signed up to discover microbes in Antarctica. It goes to show–whatever your adventure, keep your eyes open and expect the unexpected.
Update: I did make it off the ice, though this time a Delta truck (not Ivan) took us back to the runway. (Fortunately, our truck did not get stuck.)
Last week I finally got back to the Dry Valley frozen lakes, bringing cubitainers and Coca Cola. The helicopter stopped briefly at Lake Bonney to join the lab members moving out—to a new camp, at Lake Fryxell. Lakes Fryxell and Hoare (separated by Canada glacier) are on the rough side, as you can see. The ice layers open and rear out of the lake; looking down in, you feel as if looking into the maw of the Dune sandworm.
The ice layers open up, scoured by wind and pressed by surrounding ice. They do not open into the liquid water, several meters below. Only at the lake’s edge is the ice melting through. During summer, a watery “moat” surrounds the lake ice, the vast majority of which never thaws. The ice surface however does “ablate” with the wind. Meanwhile, streams form on the mountains, carrying glacier water downhill into the moat. This water is raising the level of several lakes. In winter, more water freezes at the base of the ice layer, as the top of the ice ablates; thus, there is a continual upward “treadmill” of ice.
Here is my helo ride to Fryxell:
The white fluff is ice frozen into crystal towers–very rough. You can barely climb across it. But the helo glides down across the smooth blue ice near shore–where the “moat” will soon melt. The famous “patterned ground” shows up best at 1:30-1:50.
The surrounding land looks very different than at Bonney—more gentle slopes before the mountains, full of pebbles rather than sand. The pebbled slopes form intriguing patterns.
The patterned ground (also called “periglacial landform”) consist of long straight grooves that tend to meet at hexagonal angles.
The patterned shapes can be large, perhaps a hundred meters, with deep grooves; or they can be small, local, with thumb-wide grooves. The grooves tend to collect rocks and snow; but that is not what forms them. The grooves are caused by repeated freezing and thawing of sediment watered by glaciers. The water-logged sand freezes, then contracts, forming cracks that fill with water. Each cycle of freeze-thaw digs the cracks deeper and wider.
Another puzzle is the source of all the sediment in the lake ice. Some is trapped from wind. But in some places, the sediment consists of lake mud that originally formed at the bottom of the lake. Here in Fryxell, sediment has reared up through the ice, forming a “sediment mound.”
That’s why I call this an “upside down lake”—the sediment is on top. Scientists seek clues about tiny life forms that may lie dormant there.
The nearby Lake Hoare has a similar rough ice appearance, much of it too rough for an ATV. We hiked across some of it—warily. The ice forms spindly columns, like a giant field of crystal glass. As you walk over it, the crystal goes crunch with every step. I feel guilty about crushing so much crystal—structures that might have taken years or decades to form. I feel the same about tramping through the patterned ground. Our footprints will last a long time. It is impossible to study this place without marring it a little bit.
Of course, the place has its own events of change. Note on Lake Hoare the many rocks perched upon the ice, some of them the size of a car, like the one at Bonney. Where did these many rocks come from?
The mountainsides at Lake Hoare are close, steep, and full of rocks. Camp assistant manager Renee reports that recently she heard a loud noise, and looked up to see several large rocks bounding down the slope. The rocks landed on the ice, forming impact craters. Over time, the wind will scour away the ice surrounding each rock, leaving the rock upon an icy pedestal.
Both Fryxell and Hoare are dammed by Canada glacier. To hike from Fryxell to Hoare, we had to go around the glacier.
Frequently we passed a pile of pristine blocks of ice called “glacial berries.” These glacial berries form when the glacier “calves” — that is, a large chunk of glacier falls off and crashed below. The crashing ice block fragments into clean ice. These clean ice chunks are what we collect to boil for drinking water.
On this hike we did not witness a piece of glacier fall, but we did hear a sound like a shotgun, the result of a crack forming in the glacier.
The more wind-exposed side of the glacier forms beautiful shapes, finished like porcelain. Here is a porcelain amphitheater.
What science did we do at these lakes? We collected more water samples of algae, using the winch and the Niskin bottle.
We also investigated intriguing forms of life called “uplift mats.” You can see them here—little puffs of desiccated cyanobacteria that originally grew in mats at the bottom of the lake. The mats support other life forms such as tardigrades (water bears) and nematode worms—the largests animals known in these frozen lakes.
So what are these desiccated mats doing atop the ice? How did they get here? Did they blow in from somewhere to land on the ice?
Here is a mat that Chris spotted, buried in ice. Amazingly enough, the cyano mats actually come up from below.
First, the cyanobacteria photosynthesize, producing oxygen. The oxygen bubbles eventually float pieces of mat up to the underside of the ice. Each year, more water freezes onto the ice, building up beneath the trapped mat. But at the same time, the wind is ablating the ice above. So eventually the mat will poke through the ice elevator. The mats dry out, then blow in the wind, to land in a moat—or perhaps even another lake.
Little is known of the genetics or culturing of these uplift mats. So I collected samples of uplift mats to send back home for Kenyon students to culture and sequence DNA.
Field sampling at temperatures below freezing is very different from pipetting in the lab. Most of the mats I picked up blew away as I tried to poke them into the 50-ml tube. My bag also blew away, until it was caught, thereby preventing an environmental contamination event. Another time I caused a more serious environmental event by losing a steel ice chipper down an ice hole. The metal content could alter the lake chemistry. Such events are not uncommon, with so many people investigating so many things in the lake. However, it still feels bad. It’s probably a good thing for a full professor to be reminded of what it feels like as a new student in orgo lab (i. e. like a total idiot).
Remarkably, my fingers all survived—and so did my Samsung Galaxy 3 that took all these photos and never cracked despite falling on the ice many times.