The hippies had it right: Life's a commune
By Gary Raham
Writer and Illustrator
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Although I attended college during the heyday of hippies, sex and rock
and roll, I studied science with an almost monk-like concentration. It
was also the heyday of DNA research, manned trips to the moon and the beginnings
of ecological awareness. (Remember "Silent Spring"?)
I found this very exciting. I learned about competition between species
and the struggle for existence; not as much about cooperation and shared
resources. But I failed to learn about promiscuity - a special kind of
infidelity not between individuals or even species, but between entire
phyla (creatures as different as real fish and starfish).
Wow, if the hippies had only known about that!
My thoughts recently turned in this direction after reading about a new
and significant change in human ecology: the ecology of some microscopic
critters that call our bodies home. You may not like to think about it
during mealtimes, but our skins, mouths and nether regions (inside and
out) are colonized by a host of microscopic "hangers on" that are, more
often than not, beneficial, rather than harmful. One inhabitant of human
stomachs for the past 11,000 years or so has been a bacterium called Helicobacter
pylori, or H. pylori for short. H. pylori is disappearing, however, at
least in stomachs living in developed countries like the United States.
During the 1980s scientists discovered that H. pylori played a role in
causing ulcers. Most people agree this is not a good thing. Although no
one mounted an active campaign against this microbe, better hygiene reduced
the transmission rate, and the general use of antibiotics resulted in mass
murder. In developing countries, 70 to 100 percent of children carry H.
Pylori, but in the United States only 10 percent of children are carriers.
This would be something to brag about, except that now scientists are learning
that H. pylori does some nice things for us: It kills off microbes that
wreak havoc in the esophagus. (Esophageal disorders like acid reflux and
cancer have been increasing as H. pylori has decreased.) It provides regulation
for stomach acidity; and it may even play a role in suppressing appetite.
Lack of exercise may not be the only reason our children are getting fatter.
But the incestuous behavior of nature goes much deeper than separate species
living communally. The very cells that make up our bodies are now believed
to represent a union between bacteria (like some of H. pylori's close kin)
and ancient single-celled creatures like the ones you saw in a drop of
pond water in school. Little sausage-shaped flecks called mitochondria
that produce the energy our cells (and body) need to survive carry their
own set of genes (DNA) and resemble nothing so much as "domesticated" bacteria.
Same thing for chloroplasts in plants and the thread-like structures called
flagella that keep your lungs clear of junk and power a sperm's journey
ever eggward.
A researcher named Don Williamson has also studied marine animals and came
to some startling conclusions. Seawater is a giant nursery for all kinds
of creatures, not to mention the medium through which reproductive cells
drift and meet. It's hard for the right egg and sperm to join under such
conditions. Usually a mismatch bears no results, but once in a great while
it does. Williamson was actually able to make fertile crosses between a
male sea urchin (a starfish relative) and a simple chordate (a sea squirt)
--a member of the same phylum as our fair species. Some of the larvae that
emerged showed traits from the mother, but didn't develop into adults;
others grew up into rather normal-looking sea urchin adults. Entire sets
of genes appeared to be hidden, depending on the life stage of the animal.
Williamson and others contend that such wholesale mixing of entire sets
of genes (genomes) may have happened in the past and be responsible, for
example, for things like the amazing transformation of a caterpillar into
something so completely different as a butterfly. The odds are very low
for such a thing to occur--once in 10 million years has been suggested
- but not, it would appear, impossible by any means.
Hippies are gray now and many of their communes failed. Some put on suits,
acquired mortgages and are now card-carrying members of AARP. But a few
communes survived and prospered. Cooperation and strange liaisons don't
always yield results, but when they do, the entire living world can be
remade.
Nature is a teacher with an immense notebook of lesson plans. As one of
her ongoing and avid students, I can't wait for the next class to begin.
References
- Blaser, Martin J. "An Endangered Species in the Stomach," in Scientific
American, Volume 292, Number 2, February, 2005.
- Margulis, Lynn, and Sagan, Dorion. "Acquiring Genomes, A Theory of the
Origins of Species." New York: Basic Books, 2002.
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