Tag: Biology

Inverted ant hills

If you think of a hole as positive space instead of negative space, then you can think of digging a hole as something like sculpting. Pour metal into the hole and you’ll get a sculpture that corresponds to the empty space.

This is worth considering because there is a guy, an entomologist named Dr. Walter Tschinkel, who pours aluminum into ant hills and digs up the resulting forms. As it happens, these castings are beautiful sculptural things. How do those ants, one by one, silently, in the dark, work it all out?

Here is a CBS News story on the subject: The Secret World Of Ants.

(Seen on Ben Fry’s blog)

Next up for H. sapiens: Building the big bug

I recently finished Before The Dawn by Nicholas Wade, a book about the evolution of the human race which I happily recommend.

Studying the history of human development has typically drawn on things buried in the dirt: paleontological/biological artifacts like the fossilized bones in Olduvai Gorge for one example, and archaeological/cultural artifacts like the ruins of Nineveh and Route 66 for another. The problem is that stuff comes out of the dirt… very… slowly, putting a real damper on our ability to learn quickly. Wade’s book focuses on a new kind of ore, which is the living information buried in our genes and in our languages. Genetic data in particular is a fabulous gold mine for those trying to work out our past.

Surprisingly, it’s not just human DNA that’s useful. It’s possible, for instance, to work out approximately when humans started wearing clothes by genetically dating when human lice split into head-dwelling species and clothes-dwelling species. Clever! And we’re starting to get a remarkably accurate story of how humans migrated out of Africa and populated the world.

Happily, Wade is not the least bit gun-shy in talking about evidence of evolution currently under way in humans. There is good evidence that our behavior is pacifying with remarkable speed owing to the powerful adaptive advantages of law-abiding socialization. But just as evolution selects for the important, so it forgets the unimportant. Sadly, we’re shedding our sense of smell with alarming speed. A good nose makes your dinner taste good, but it’s not especially selected for. Rats can synthesize their own vitamin C, but humans lost that ability long ago. As long as you take your Flintstones vitamins, who needs to synthesize the stuff?

Obviously this all leads to the big question: what’s next? Wade doesn’t speculate much, but I will. It seems clear that modern medicine is going to allow our onboard health maintenance to get weaker and weaker. Just to pick one example: accurate, timely vaccines mean our native robustness won’t be put to the test, and that which isn’t selected for drops away. This may appear disturbing, but really what we’re doing is evolving an outboard immune system. We are offloading many heretofore intrinsic biological tasks to the next level of abstraction: the community.

This includes the outboard brain. Networks are the nervous systems for the big bug, the communal organism that we are becoming. Just as individual cells had to make some dramatic accommodations in order to form multicellular organisms, our native behaviors will be ever more conducive to hive action. We’ll sure have to get rid of all the errant terrorism genes before we can manage long term space colonies. It only takes one crazy person to wipe out a space village.

Evolution and geology

I just finished reading Sean Carroll’s book The Making of the Fittest. Subtitled “DNA and the Ultimate Forensic Record of Evolution”, it’s the follow-on book to Endless Forms Most Beautiful. In this book Carroll devotes several chapters to demonstrating how, against our natural intuition, there really is enough time (given a few hundred million years) for DNA to mutate bit by bit and still make amazing new structures like eyeballs, wings, and that pink dangly thing that hangs at the back of your mouth.

Carroll also points out that while almost everything is in flux, genetically speaking, there are some stretches of DNA so crucial to life that they never change. Which is to say, they can’t change because any variation would be fatal. Here, for example, is a six amino acid stretch that has been found in every single living thing: KNMITG. It’s an immortal sequence, unvarying across more than a billion years.

The last chapter deals with the controversies associated with teaching evolutionary theory in public schools. This is well-traveled ground, but it got me thinking about how much the opponents of evolution focus on man, monkeys, and biology class. But shouldn’t they be attacking geology too? Some of them do, insisting, for example, that the Grand Canyon formed during Noah’s flood. But it seems that a serious and consistent creationist ought to stick those little “this is only a theory” labels in every science book on the shelf. The astronomy book, the geology book, the physics book, they should all be thrown out the window along with The Origin of Species. Why is poor old Darwin always taking the heat?

The big brain

I was recently reading Sean Carroll’s excellent book on evolutionary developmental biology, Endless Forms Most Beautiful, in which he says that “brain size [in humans] roughly doubled in a million years.” This was a dramatic (and expensive) departure in the brainweight-to-bodyweight ratio compared to all other mammals. Carroll goes on to say:

The brain is a very expensive organ in terms of energy consumpution, drawing up to 25 percent of an adult human’s energy (and 60 percent of an infant’s).

Who knew the brain was such a hog? You can rest your legs and unshoulder your weary load, but your brain keeps drawing current rain or shine. And a good thing too. An evolutionary stockbroker might describe the relationship between the brain and the evolutionary fate of Homo sapiens as this: an expensive investment, but ultimately worthwhile.

These words were in my head as I recalled some articles I was reading about the growing electrical appetite of data centers. It turns out that data centers and server farms are sprouting like mushrooms along the Columbia River in Washington and Oregon. Why? Because that’s where the cheap hydroelectric power is. These giant computing centers, erected in rapid succession by Google, Yahoo, Microsoft, and others are hot, hungry, and growing fast. The electrical power consumed by computers has become one of the most significant costs of a modern corporation, particularly since it has the knock-on expense of driving cooling costs too. Electrical companies joke about giving away computers and making up the cost on juice.

Who knew the computer was such a hog? We can regulate our trucks and trade in the Hummer for a Prius, but the great Google brain keeps drawing current rain or shine. Every day, as we commune by keyboard with the net, banging out our neuron’s part, the network is evolving.

I’m guessing it’s an expensive investment, but ultimately worthwhile.

Molecular biology animations

dna-replication.jpg
A few years ago, PBS ran a series called, simply, DNA. It included some of the spiciest, most inspiring animations of biological molecules in action that I’d ever seen. I longed to linger over them and savor them, but they came and went so fast in the show, and until this evening I had no idea who did the work. Over at information aesthetics I came across the 2006 infographics winners from Science magazine. One of these winners was Drew Berry of the Walter and Eliza Hall Institute in Melbourne, Australia. He’s the guy who made the beautiful animations.

Armed with this information, I was able to track down the mother lode in short order. Here is a page pointing to the QuickTime videos that gave me the shivers. May I particularly recommend the insane fruitbat circus otherwise known as DNA replication. If a Divine and Perfect Intellect is responsible the design of this unlikely contraption, somebody’s got a lotta ‘splainin’ to do.

Finally, here is an interview with Drew Berry about how he got the gig for the DNA TV series.

Dirt vaccines

I knew it would come to this: dirt is officially good for you. The “hygiene hypothesis” has received another shot in the arm in a recent talk by Professor Peter Openshaw of Imperial College, London: How ‘Dirt’ Could Educate The Immune System And Help Treat Asthma.

What is the hygiene hypothesis? It’s the idea that being exposed to filth early in your life strengthens your immune system, whereas being constantly scrubbed clean by anxious parents merely sets you up for a clock-cleaning viral sucker punch. Your wimpy little immune system will never know what hit it. The same hypothesis explains why polio’s awful bloom happened alongside the rise in modern plumbing. As Jane Smith says in her book Patenting the Sun: Polio and the Salk Vaccine

Put simply, paralytic polio was an inadvertent by-product of modern sanitary conditions. When people were no longer in contact with the open sewers and privies that had once exposed them to the polio virus in very early infancy when paralysis rarely occurs, the disease changed from an endemic condition so mild that no one knew of its existence to a seemingly new epidemic threat of mysterious origins and terrifyingly unknown scope.

As I’ve mentioned before on this site, drinkable pig parasites (i.e. barnyard filth) are now being used to combat Crohn’s disease. And now, Professor Openshaw is telling us that the alarming rise in asthma may be due to the same cleanliness your mother so cherished. However, “having many older siblings, attending day care at an early age, or growing up on a farm can help in promoting resistance to disease.” Eventually our best vaccines will consist of finely tuned warmed-over sewage.

The fruits that civilization has given us, boons such as high-fructose corn syrup, Wonder Bread, partially hydrogenated cottonseed oil, and now personal hygiene, we must eventually surrender in the name of robust health. Take two mudpies and call me in the morning.

Crohn Banished by Diet of Worms

Your body evolved in an environment that was vastly filthier than the one you now inhabit. As a result, living with all this good hygiene can actually cause real problems in cases where your body has come to depend on filth. Your gut expects to manage large numbers of parasitic whipworms, for example, and, for the sophisticated readers of this weblog anyway, this just isn’t the case. For people with inflammatory bowel diseases (IBDs), like Crohn’s disease, the gut is violently wrestling with an opponent that never showed up. Or that’s the theory proposed by gastroenterologist Joel Weinstock.

Weinstock had a brilliantly testable idea: feed IBD sufferers a diet of worms. The clinical results, as reported in this New Scientist article, are nothing short of astonishing. Seventy of the hundred Crohn’s sufferers in the study experienced complete remission of the symptoms. If this all holds up, you will soon be able to order a “drinkable concoction containing thousands of pig whipworm eggs” (this from the same company, no lie, that brings you quality medicinal maggots and leeches).

I sense an exciting new high-concept juice bar business opportunity. The “Old McDonald” will be a lightly frothed blend of wheat grass and pig whipworms that can be spooned right out of the barnyard.