Blue Planet 2

Blue Planet 2. Problem solving and coordinated group action by clownfish. Who knew? Besides other clownfish, I mean. And what’s with the meter long carnivorous worms? Teeth sharp as pinking shears, hence the name: Bobbitt. As in Lorena. David Attenborough left that part out. The damn things can get up to ten feet, I read, like the sandworms in Dune. They can lop a foot long fish clean in half. A Devonian Era nightmare, giant meat eating invertebrates. Acid visions of carnivorous trilobites. Thankfully trilobites went extinct long before we ever got here. (Nor were they ever giant, nor scary, nor anything but invertebratefully adorable, like the little darlings scattered about the bookshelves here.)

Then the scene with hundreds of reef sharks swimming menacingly above thousands of groupers. Suddenly l’amour drives the groupers mad and they rush upward into the sharks, shedding eggs and milt to the seven seas. The sharks go into a feeding frenzy and the surging waters are all blood and roe and sperm, a veritable fish fuck massacre. There seems to be something dreadfully amiss there. Or not. No one ever said natural selection was logical. Ghastly, maybe.

The clownfish were so neat and orderly and mannered in comparison. They’ll go far. Check back in a hundred million years. Groupers will have vanished and clownfish will be talking and thinking vast, deep thoughts.

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Oblivion

The Darwin Awards have nothing to do with Darwin or natural selection. It’s just people doing dumb stuff. And people doing dumb stuff has nothing to do with genes, which is all that natural selection is about. The people who really deserve Darwin Awards are adults who never had children, because they selected themselves right out of evolution. Genetically speaking, I lose, and lose as bad as it is possible to Darwinianly lose. I do get the cold evolutionary comfort of having a brother who spawned four sons, meaning that some our shared genes got passed on to another generation. But the fact that he spawned no daughters limits the long term genetic possibilities. So it goes.

Memetically I haven’t done too bad. Some of my memes might last a while past me. But civilizations fall eventually and take most of their collective memes with them, certainly the ones based on language. At some point languages themselves disappear and my beautiful prose would read like the stilted translations of cuneiform poetry, the life sucked out of them. In the unlikely event that anything I ever wrote had lingered on for generations, it will vanish into the ether when English vanishes into the ether, gone forever, my written thoughts dead as my genome, and the very last proof that I ever existed will fade into nothingness, as if I had never existed at all.

Groovy.

Losing it in the tabloids

Brick Wahl losing it in the comments section of a British tabloid:

There is almost nothing correct in this article. Aegirocassis benmoulae was not a lobster. It was not even kind of like a lobster. Not even sorta kinda vaguely like a lobster. Indeed, there is virtually no connection whatsoever between Aegirocassis benmoulae and lobsters. Had you printed the actual artist’s rendering of Aegirocassis benmoulae your readers would have noticed, after tearing themselves away from Kim Kardashian’s ass, that the lobster comparison was a bit of a stretch. Indeed we human beings are more closely related to frogs, flamingos and lungfish than Aegirocassis benmoulae was to a lobster. Which makes me a six and half foot lungfish and you a hopefully soon to be extinct failure of a science editor.

Somebody had to say it, if David Attenborough won’t.

Alas, this comment was deleted by The Express. I knew I shouldn’t have said Kim Kardashian’s ass. Arse maybe.

express_logo 

Lobsters the size of HUMANS swam the seas 480 million years ago, new fossil reveals
A Caribbean lobster

A GIGANTIC lobster bigger than a human once populated the oceans, a new fossil find has revealed.

http://www.express.co.uk/news/nature/563304/Lobsters-size-HUMANS-swam-seas-480million-years-ago

Quirks of fate

It seems that 70,000 years ago the global population of homo sapiens was reduced to less than 26,000. Apparently they teased out that bit of info through some genetic analysis. As humans were by then in Africa and across much of Eurasia, that means we were very sparse on the ground. All seven billion of us spring from remarkably small numbers of people. Indeed, it’s been suggested that as few as seventy individuals came across the Bering Strait land bridge to eventually people the entire western hemisphere. We’ve had more than seventy people in our pad at parties. I never thought of them as a genome before. Well, I did once and got my face slapped. But I digress.

A million or so years ago our antecessor species Homo erectus seems in the genetic analyses (if I knew how they do this I’d tell you) to have been reduced to less than a thousand individuals….and remained like that on the razor’s edge of extinction for maybe a hundred thousand years. Everything we are was dependent on a population the size of a very small town or a medium sized high school or the fans of failing rock band in a big, mostly empty concert hall. Somewhere in that tiny population was some of us, genetically. Whatever genetic factors helped members of that population survive a particularly brutal hundred thousand years of Darwinian natural selection (as other related human species went extinct) lies deep in our own genome. And when 70,000 years ago something happened globally that reduced Homo sapiens to less than 25,000 individuals, we survived while the last of Homo erectus died out, unable to survive what it had once survived for a hundred thousand years. No one ever said natural selection was fair. It’s anything but. The fossil record is full of species of humans and proto-humans no longer here. Fleshed out by talented artists, they gaze at us with all the pathos of a Rembrandt. You can sense their intelligence and emotions. Then you look at the skulls again, bare and ancient and hopelessly extinct. There but for quirks of fate, is us.

A rock on my desk

Damn, thought I found this nifty chunk of basalt out near Anza Borrego. It’s got a flat bottom (no jokes) and it is yet another rock I have on my desk for allegedly utilitarian purposes. This one, I told my wife, would make a great paperweight. But I just like rocks. I stood there in the ninety degree heat just west of the Salton Sea Basin, flowers in a zillion colors in every direction, fixated on the rock in my hand. I love basalt. I pictured it forming far below my feet, rising, cooling, a tiny bit of the earth’s mantle cooled and frozen into hard, simple stone. I was hoping it was a billion years old. I always hope basalt is a billion years old. It wasn’t. The basalt in the area was a mere hundred million years or so. Still, it does make a good paper weight, even if it’s a relative infant, mantle wise. There is something fundamental about basalt, a strength, a simple plainness, an assurance that our planet is solid and very real in the vast emptiness of the universe.

But a few minutes ago, eyes drifting from the TV where the LA Kings were being humiliated by yet another Canadian team, I started looking closely at my paper weight again. The lighter, granitic smears bothered me. Why were they there? And I hadn’t paid much attention to the bits of white on the surface. With the Kings collapsing in their own zone again, I grabbed a magnifying glass. It’s not a very good one, but through it I studied those white bits. Damn–structure. I screwed up my eyes and squeezed every bit of nearsighted vision I had remaining. Sure enough, there it was-a cylinder, ringed, tapering. Perhaps some sort of gastropod shell, some kind of pointy shelled snail maybe an inch long. I look carefully over the rock and see similar structure in some other bits. Shells. This is limestone. A very dark limestone. I took it into the kitchen and let water run over it. Wet, it’s nearly black. I found an article online about black limestone, and how to tell it from basalt. Basalt typically contains some larger non-basalt crystals. I pored over the surface of the rock again with the magnifying glass looking for crystals. Nothing. Just little hints of fossils. Bits of living things. This rock is made of organically produced structures that once contained soft bodied, skeletonless creatures, invertebrates. Organisms that needed the shelter of a shell they made themselves. Animals trying not to be eaten.

It dawned on me that I was holding in my hand the end result of the evolution of predators, of meat eaters, because before predation there was no need for shells. Everybody ate algae. There was need for shells or hard body parts or beaks or teeth. But I was holding those long deceased animals’ shells. A half billion years of protection against murder reduced to its basic minerals and a few whole bits and congealed together on the floor of the ocean after the animals shed or died in them, then pressed down by the weight of millions of years of sediments above, then hardened into rock, into this limestone. It’s like holding a handful of millions of untold histories.

The black color? I suppose it’s black the way some shales are black, shales of hardened darkened mud. I really don’t know. Basalt would have been so simple. Formed deep beneath us under the tectonic plates we stand on, and stretched out into ocean floors, then lifted up as the plates crunch into each other, pushed upward into mountains and then broken down again by water and wind and earthquakes, carried along by floods too many to count and left in the dirt at my feet between bunches of violet sand verbena and a few wild poppies. A simple story, basalt. Now I have instead a compacted chunk of the story of life, and I stare at the damn thing and feel hollow.

I’m not sure when exactly the zebra danios turned into killers.

Our zebra danios have gotten scary. Where once they’d dash about madly at the top of the tank waiting for the flakes of food, now they wake slowly from sleep, huddled together, then in a three fish column begin moving slowly (not their usual frantic dash) into the plants, moving around them, seeking meat. The flakes of fish food float down all around them but they pay no attention. They keep prowling, methodically, maybe an inch or two from the bottom of the tank. I’ve come to suspect that this was how they killed the other fish, by catching them before they were completely awake there amid the plants. I can only imagine that all three would rush in, striking, chomping, killing. In the wild they eat insects and crustaceans and worms, so they are hunters, yet in the thirty some years we’ve been stocking our aquariums with them I have never witnessed them do anything more than grab flakes of fish food drifting by. I have certainly never seen this sort of apparently coordinated behavior. It seems that almost every vertebrate has within it the predatory behavior. We are all hunters. Hell, it was predation that drove evolution itself, the whole Cambrian Explosion with all its crazy speciation was the result of the ever evolving contest between predator and prey. And here, somehow, in our little aquarium, something turned these little inch and half long fish from eaters of fish food to eaters of fish, eaters of even their own kind (as there were five of them just two weeks ago). All was peaceful until the clown loach died. That loach, though never deliberately bothering any of the other fish, was at seven inches long to them like a whale shark is to us. It ruled the floor, digging up snails. The danios stayed up several inches in the tank, away from its sudden movements. But then the loach, one day two or three weeks ago, was dead. Old age. I noticed the next morning that the danios were down zipping around at the bottom of the tank. The neon tetras calmly minded their own business, the two glass catfish scooted about. Everyone, danios included, got very excited at feeding time, like they always did. Everyone swam around excitedly, grabbing bits of tetra min flakes floating by.

I’m not sure when exactly the danios turned into killers. Within two weeks I realized that all the fish were gone but these three zebra danios. Alone in the tank, they chased each other madly about, zipping one way, then another. I was mystified. Where had all the other fish gone? I did some research, and found desperate pleas on aquarium websites. “Help, my zebra danios are eating each other!!!!” or “My zebra danios are killing my other fish!!!” I read in shock just how murderous the little beasts can be. No one seemed to know why, but there was usually a dominant fish that sets it off. A handy bit of evolution, that, where some members of the species will suddenly go rogue, turn alpha, and eat everything piscene in sight. Obviously there is a genetic advantage in there somehow. Perhaps a surge in zebra danio testosterone. But I have no idea. Looking at the tank again, one of the danios is swimming like a lunatic now, frenzied. The other two have ducked behind the leaves. Perhaps there is murder afoot.

zebra-danio2

It doesn’t look like a killer.

A shark goes for a walk

Nice bit of convergent evolution on display here when you compare this shark with the fish that evolved into all us four-limbed landlubbing tetrapods. Our own fish ancestors, though, were lobed finned with bone skeletons (like coelacanths, or an even better example, lungfish). Mudskippers, a walking ray-finned fish, are another bony fish though unlike either early tetrapods or this epaulette shark, it uses only its pectoral fins and not the pectoral and pelvic fins. Mudskippers pull themselves around by their front limbs. Tetrapods and epaulette sharks walk. Or proto-walk. They use all four limbs. Watching this little epaulette shark is eerily like watching a monitor lizard. It’s hard to think of anything strictly terrestrial that moves like a mudskipper. Yet it is conjectured that most early tetrapods like Tiktaalik lived much like mudskippers, and not much like this epaulette shark. Go further back a few million years into tetrapod evolutionary history and you can find lobed fish, such as Panderichthys, that probably lived lives much like our walking shark. Unlike mudskippers and we tetrapods, however, sharks are famously boneless. They leave lousy fossils, mostly teeth. Some really terrifying teeth, too. Megalodon has left its thirteen inch incisors scattered in fossil beds world wide.

But this shark here is maybe three feet long and quite harmless, and I watch and rewatch him perambulating across the Coral Sea floor cartilaginously, a nifty trick, but severely limiting if one is thinking about evolving into a land animal. Without the buoyancy of water, one needs the support of a bony skeleton. Gravity is a bitch. But one also needs a bony skeleton to evolve fins into limbs that all of us tetrapods use for legs, arms, feet, hands, fingers, toes, and wings (and sometimes back into fins). The jointedness of bones seems to open up a wide range of mutation possibilities–and evolution is all about mutations–that cartilage just does not seem to have. Sharks and us have been on dramatically divergent evolutionary paths since we last shared a common ancestor well over four hundred million years ago. And shark evolution, though impressive enough in its sleekness, is vastly less varied than that of those of us who spring from the homelier lobed finned fishes (and less varied than the bony ray-finned fishes, which make up well over 99% of all fish species but never left the water). Aside from our perambulating friend here, all sharks (and their cousins, the rays) swim, while nearly all of the tetrapods (i.e., four limbed creatures who live on land) walk. But the same mutational capacity that enabled the first tetrapods’ pectoral and pelvic fins to evolve into a dizzying variety of limbs continues to enable tetrapods to evolve amazing adaptations with their limbs. Vertebrate flight has evolved three times (pterosaurs, birds, bats) while frogs and kangaroos hop and snakes and legless lizards slither limblessly. There are lizards and a number of mammals who glide. Pangolins go totally post-tetrapodal and curl up into an armored ball and hurl themselves down hillsides (the sort of thing that does not show up in cladistics.) A few tetrapods have even gone back to the ocean for good to swim again, the front limbs evolving again to pectoral fins, the backs legs disappearing entirely, as if four hundred million years of terrestrial evolution had all been some terrible mistake.

Yet the simple advantages of walking along rather than swimming over a shallow sea bottom (watch the video at about 25 seconds when the shark stops to peer into a cavity, looking or smelling for possible prey) apparently led this shark along a trail of mutation that eventually allows the thing to walk with ease. And it is extremely unusual for a shark. The range of design among sharks and rays is very minimal. Very few sharks don’t look very similar to other sharks. Rays look like rays. A Greenland shark is notorious for being so old and creepy and strange looking. But it looks very similar to almost all other sharks. An aquarium with nothing but sharks would be a pretty dull looking aquarium. They look a lot alike, they act a lot alike. Then we see a video of a epaulette shark walking along the ocean floor like it’s the most natural thing in the world.

A prowler of tidal zones, an epaulette shark can survive for hours in extremely low oxygen pools. It cannot breathe air, though, as mudskippers and lungfish do and our own water’s edge ancestors once did. Rather this shark has evolved a way to reduce blood flow in critical periods to all but the brain and heart. Handy, but a no go as a terrestrial adaptation. One needs to breathe air to make it on land. So this remarkable shark is no more like us than we are like it. It’s a marine animal who sometimes can stay on the edge of land for a couple hours, just as we are terrestrial animals who sometimes can swim with the fish for short periods.

But it was the combination of using fins to lift and carry across surfaces (i.e., walking) where swimming was difficult or impossible, with getting oxygen from the air via lungs (i.e., breathing) instead of taking oxygen from the water via gills, that made vertebrate land animals possible. (Insects were already there–doubtless tetrapods were eating them–but they had evolved from marine invertebrates, and our last common ancestor was somewhere deep in the Pre-Cambrian). There are over 30,000 species of tetrapods today–7,500 amphibian, 10,000 reptile, 10,000 bird and over 5,500 mammal species–and all remarkably seem to have come from one species of lobed finned fish that managed to combine both fin walking and air breathing, and had an unusual capacity for mutation in pectoral and pelvic fins. There was a wide range of these mutated fins at first–as many as eight digits on each fin–before the final five toes/fingers was arrived at. (Perhaps the occasional six toed kitten or baby are a mutational echo of that.) There seem to have been many species that could do so and apparently the lush and swampy Devonian shore line was rich enough in food and varied enough in niches a half billion years ago to allow evolution to run riot. But apparently only one of those species led to all the four footed or two footed and two armed or winged creatures breathing air today, including us. And while this beautiful little epaulette shark has nothing to do with any of our own evolution since the Devonian, as it is only very distantly related to any of us tetrapods, watching it trundle across the ocean floor does give a brief glimpse of what our own origins looked like nearly half a billion years ago.