Systems, a Powerful Part of Evolution

Speaking of ant rafts (my last post), I recently read The Superorganism: The Beauty, Elegance, and Strangeness of Insect Societies, by Bert Holldobler and E. O. Wilson.

         “Superorganism” is a good name for an ant colony or a bee colony or a termite colony.  The individual insects in such colonies are not like you and me.  They don’t strive for individuality.  Instead, they are part of a highly efficient, highly successful system.

         To quote Holldobler and Wilson, “The principal target of natural selection in the social evolution of insects is the colony, while the unit of selection is the gene.”  Ants truly live the principle of “All for one, and one for all.”  Though the worker ants do not themselves reproduce, the expression of genes in each individual responds to colony-wide signals from the queen and from one another; so the individual genes that lead to success are favored.

         Then there is a quite different book, Wetware: A Computer in Every Living Cell, by Dennis Bray.  Much simplified, Bray’s point is that in a unit as small as a cell, the activities of thousands and millions of molecules are like electric circuits, providing information and carrying messages that lead to actions.

         Bray describes the complex, overlapping systems of molecular signals within a cell.  Then he considers the possibility that it is not just genes, but systems that control the expression or non-expression or slight expression of genes that actually evolve.  Some combinations of expression are more successful than others for a particular species.  So not only the genes in question, but the control systems that lead to successful expression patterns, are conserved.

         I find this whole idea of evolving systems just breathtaking.  How about you?



Wonders of Evolution: Ant Rafts

Having seen the following fire-ant raft experiment:

 I went in search of more, and found the following exquisite film.

Hygiene Leads to Disease? Part 2: Autism

My last post was about how parasitic intestinal worms seem somehow to protect against inflammatory intestinal autoimmune disease.  People from rural environments and developing countries, where such parasites are common, do not suffer such inflammatory diseases.  Stewart Johnson, a deeply concerned father of an autistic child has taken this further.

         Johnson researched all sorts of autism cures in hopes of alleviating his 13-year-old son’s self=destructive behaviors.  He knew that one idea about autism is that some of the symptoms are a result of inflammation of glial cells in the brain.

         As you can see from my two brief posts last week (May 17 and 19), the snake oil salesmen have been quick to hop onto the inflammation-causes-autism bandwagon.  But that doesn’t mean inflammation isn’t part of some forms of autism.

         In search of inflammation cures, Stewart Johnson came across the research I reported in my last post.  Wondering if parasitic helminth (Trichuris suis) worms might help his son, Johnson got in touch with his son’s doctor, Eric Hollander, who helped him get a sample of the worm eggs (T. suis ova or TSO) and with Joel Weinstock, one of the researchers who found they could alleviate Crohn’s disease and ulcerative colitis. 

         With their help, Johnson tried the worm therapy and found that it did indeed alleviate the terrible, self-destructive autism symptoms his son was suffering.  Years later, the son, now twenty, is healthy on bi-weekly doses of TSO.

         What a miracle!  Now the task for researchers is to figure out what the worms are doing to modify immune systems so that inflammation goes away.  Meanwhile, see Stewart Johnson telling this story below.



Hygiene Leads to Disease? Part 1

Not so long ago three health researchers, Joel Weinstock, Robert Summers, and David Elliot discovered a really good thing about some parasitic worms that infect the human gastrointestinal tract.  The worms keep their host humans free of certain autoimmine diseases, such as Crohn’s disease and ulcerative colitis.

         First the researchers noticed that these autoimmune diseases are virtually unknown in the third world and in the rural south of the United States.  Then they noticed that the parasitic worms common in the intestines of the migrants didn’t seem to make them sick.  Finally, they found that as populations immigrate from the third world to the U.S., or migrate from the rural south to the urban north, Crohn’s disease and ulcerative colitis begin to be a problem.

         Could it be, thought the researchers, that parasitic helminth worms (EEEUWWW!!!) are actually good for us?  In eliminating them from our diets and ours bodies, have we left ourselves vulnerable to diseases the parasites somehow control?

         Using helminth worms from pigs that don’t become permanent residents of humans, the researchers infected mice with inflamed intestines with helminthes and found the inflammation was alleviated.  Then they infected volunteers suffering from Crohn’s disease and ulcerative colitis and found their symptoms were significantly improved.

         Wow!  Once again it turns out that evolution knows more than we do.  Once again it turns out that humans (and many other animals) evolved to make good use of the species that were here before us.  And there’s more to this worm thing, even some good news about autism…stay tuned!



How Can Infinitesimal Animals Be Geological Historians?

In my last post, I described the Bryozoans, animals that are so small, you can’t really see them without a microscope.  Yet these tiny creatures contain complete animal systems and exist in myriad, fascinating shapes.

         The Bryozoans have been subjects of early microscopic studies hundreds of years ago.  As such, they were mistaken for plants.  They have been subjects of more recent, advanced microscopy, when improved scopes, dissection, and slide preparation showed them to be animals.  They have been subjects of very recent molecular examination, when it became possible to study their relationships to one another with DNA data.

         And now, in a neat reversal, they have switched from being the subject of study, to providing data for a different scientific quest.  Some Bryozoans offer geological data about Antarctica. 

         Groups of similar species of Bryozoans have been found on the shores of both the Weddell and Ross Seas, which are now separated by 1500 miles of ice sheet in Antarctica that is 2 kilometers thick.  The similarity of the Bryozoan species suggests that at some point, perhaps 125,000 years ago, the ice sheet had melted, and there was a connecting seaway between the two Antarctic seas.

         So here are these Bryozoans, once again keeping up wonderfully with modern, scientific research.  What a wonderful phenomenon.