Wise worm

For more than twenty-five years, scientists have known the exact wiring diagram of the three hundred and two neurons in the C. Elegans roundworm, but in at least half a dozen attempts nobody has yet succeeded in building a computer simulation that can accurately capture the complexities of the simple worm’s nervous system.

-- Gary Marcus.

Unlike Moore's Law for processors, understanding of how the brain actually works, of the computations and circuits that are underlie neural function, is not doubling every eighteen to twenty-four months.

P.S. See also Worms do the wave to translate messages.

A salmagundi of worms

Twelfth in a series of notes and comments on The Book of Barely Imagined Beings

Chapter 6: Flatworm

page 83: Penis worms. A study on the development of priapulids (penis worms)"throws doubt on a feature that has been thought for more than 100 years to define the largest branch of the animal tree of life." For more on deuterostomes see marginal note on page 47.

page 83: Other posts on this blog relating to Ediacaria here.

page 85: other creatures evolved more formidable features for attack and defence. See, for example, Diania cactiformis.

page 87: H mephisto. Here is an image of a "devil worm," the deepest-living animal yet found.

page 87: C. elegans. Here is an image from The Open Worm Project (used to illustrate this article):

page 88: Annelids, the segmented worms, are a large and diverse group. They include scale worms, polychaete worms with an eversible pharynx. Most of the time their jaws are tucked away, but when the worm wants to feed, the entire front of their throat rolls out of their mouth.

Polynoid scale worm

page 88: Christmas tree worms. Shown here:

page 91: tapeworms and other lovelies. Graphic and horrible but fascinating: Brain Parasites, California’s Hidden Health Problem.

Only connect

I like to ask people to imagine the map that you see in the back of in-flight magazines but to imagine that the map had one hundred billion cities and out of every city there were ten thousand flights. That's the kind of complexity in your brain.

...To do entire the connectome for a human brain would be a goal for forty years from now. Right now we're...shooting for a small chunk of brain, maybe a cubic millimetre. That would be 100,000 neurons and billion synapses. That's a tall order in itself.

-- Sebastian Seung, author of Connectome, talking to Nature Neuropod
 

The connectome is of C Elegans has 300 neurons and 7,000 connections