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12/04/2003
On Fowl and Fossils
I presume that most of us, vegetarians and those who don’t like
fowl excepted, have partaken of a bit of turkey over the past
week. Last week we got a call from a good friend from Turkey
wishing us a happy Thanksgiving and inviting us to her
daughter’s wedding, to be held in Turkey next year. Our friend,
who now lives in the San Francisco area, was preparing to cook
(what else?) a turkey for her Thanksgiving dinner. My wife and
I were fortunate enough to be invited by Lamb creator Harry
Trumbore and his family to their house for Thanksgiving dinner.
Appropriately, just before dinner, about 10 wild turkeys strolled
into the backyard! So, just before we feasted on one of their
domesticated brethren, Harry went out to toss them birdseed.
Three deer stood in the background watching the tableau.
It’s clear that those wild turkeys are clever birds and have trained
Harry quite well. When the birdseed supply is depleted, they
march up to the sliding glass door and make it known they would
appreciate some attention. Turkeys have gotten a bad rap when
it comes to their intelligence. I looked up the word turkey in our
American Heritage dictionary and found these slang definitions:
“a stage play or other production that fails; a person regarded as
continually inept; a misfit.” On Thanksgiving evening, PBS
carried the Mark Twain Award show honoring Lily Tomlin and
Broadway star Elaine Stritch mentioned appearing in a “turkey”.
This poor maligned and overeaten bird has not had many come to
its defense. However, a Thanksgiving Day news item posted on
AOL News cites one Tom Savage as trying to set the record
straight. Tom is concerned about a story that is unfamiliar to me
but seems to be common in turkey circles. The story is that
turkeys are so lacking in smarts that they will look up at the sky
when it’s raining and keep looking up there until they drown! I
have no idea whether this is true or not.
Savage, a poultry scientist at Oregon State University, has spent
three decades studying all sorts of birds and their genetic makeup
and is an expert in this field. It’s true that some turkeys do cock
their heads skyward for a minute or longer. But these birds are
not stupid. They suffer from a genetic disorder - “tetanic
torticollar spasm”. This disorder shows up shortly after affected
turkey chicks hatch. The spasms, in which the head is snapped
back, typically last a few seconds; occasionally one will last a
minute or longer, thus giving rise to the “stupid stare” story.
On the Oregon State University Web site, you can see pictures of
chicks exhibiting this and other genetically induced behaviors.
Savage points out that we humans are responsible for some other
turkey traits that lead us to think of them as stupid. We’ve bred
them to be heavy and ungainly and when they try to fly it’s not a
pretty sight. The wild turkey, on the other hand, is a good flier
and I can vouch for the fact that the wild turkey’s I’ve seen are
surprisingly slim, nothing like the gobblers we serve up at
Thanksgiving. However, the ones we saw at Thanksgiving did
appear plumper than I recall them earlier this year. Too much
birdseed from our StocksandNews cartoonist?
Having debunked the stupid turkey story, let’s turn to another
claimed debunking. Regular readers may have noted several
recurring themes in these columns. One is that any new finding
or postulate of significance generates controversy. Another is
that controversy is especially likely in the fields of ancient
biology and geology, notably when it comes to origins of life and
its subsequent evolution. A third theme in recent months has
been the unusually large numbers of cases where the work I’ve
chosen to discuss involves researchers from Australia. A recent
issue of Science contains a paper that fits all three categories.
The controversy concerns whether or not certain tiny objects are
fossils of an ancient form of life. The most publicized case of
this type was a report some years ago that a meteorite, which
originated on the planet Mars, contained tiny worm-like forms.
These were taken to be evidence of life in Mars’ past, naturally
generating a lot of excitement. Today, the preponderance of
scientific opinion is that these wormy things were really the
result of chemical reactions and not evidence of life. A minority
still stick to the opposite belief.
But what about here on Earth? I’ve probably mentioned in a
previous column fossils dating back 3.5 billion years. If so, I
was likely referring to tiny objects claimed to be microfossils of
cyanobacteria found in rocks in the Warrawoona area of
Australia. William Schopf at UCLA published on this subject a
decade ago. You may recall that cyanobacteria are the critters
that changed our planet’s environment by emitting oxygen into
the atmosphere and paved the way for all of us oxygen-breathing
types. The microfossils are wormlike structures and, right from
the start, Schopf’s identifying them as bacterial fossils aroused
spirited debate. Enter the terms “Warrawoona”, “Schopf” and
“fossils” on your search engine and you’ll be surprised at the
amount of material pro and con on the subject.
I won’t attempt to review or evaluate the conflicting views but
the most recent debunking appeared in the November 14 issue of
Science. The paper is titled “Self-Assembled Silica-Carbonate
Structures and the Detection of Ancient Microfossils” and is co-
authored by J. M. Garcia-Ruiz of Spain and five Australian
colleagues. What they did was to take some common chemicals
that are or were present in the Warrawoona area, mix them in
contact with air and see what happens. Specifically, they took a
barium salt and alkaline sodium silicate solutions and varied the
pH. The solutions picked up carbon dioxide from the air and
barium carbonate crystals coated with silica formed just sitting at
room temperature. These crystals aggregated to form tiny curved
objects that closely resemble the microfossils of Warrawoona.
The microfossils were coated with a darkish coating of complex
organic material. So, Garcia-Ruiz and his Aussie buddies dipped
their own “fossils” in a mix of phenol and formaldehyde and
heated the mix. A brownish complex organic coating was
formed. Voila! You don’t need life to form the objects claimed
by Schopf to be cyanobacteria fossils. Or do you?
Schopf concedes that the work is “very interesting and
ingenious” but contends that the resemblance to his microfossils
is “superficial”. He claims that his microfossils had voids that
were walled-off whereas the new structures are rods or hollow
tubes. My take on the situation is that the presence of life of
some sort over 3 billion years ago is well established, as is the
role of cyanobacteria. Finding fossils of such delicate structures
would be truly impressive but not essential to confirm early life.
For example, in 1998 Australian researchers Adriana
Dutkiewicz, Birger Rasmussen and Roger Buick of CSIRO
Petroleum and the Universities of Western Australia and Sydney,
respectively, discovered oil. Their work, published in an
October 1998 issue of Nature, consisted of looking at very thin
sections of 3 billion year old rocks from Australia, Canada and
South Africa. Using electron microscopy and fluorescence
techniques, they found tiny droplets of oil, less than a thousandth
of an inch in size. This wasn’t an oil gusher that would make
them or their institutions rich. However, this was the world’s
oldest oil, over a billion years older than any oil deposits known
at the time. Where does oil come from? From accumulations of
microorganisms such as single cell bacteria, according to the best
evidence to date. There was life around even if the microfossils
of Schopf and company prove debunked.
Whatever, the ultimate resolution of the microfossil controversy,
none of the involved parties or their works should be termed
“turkeys”. It’s often spirited controversy that drives others to
resolve the controversy or even to come up with unexpected
findings of greater importance.
Allen F. Bortrum
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