Some
of the discoveries of scientists are monumental, like the discovery
of DNA or the discovery of the cosmic background radiation. But in
other cases a scientist may find something tiny and borderline, but that doubtful little thing may be hyped up to look as if it was
something mountain-sized.
An
example of such hyping might perhaps be found in a recent
announcement about alleged microfossils. The controversial
geological specimens were discovered in Western Australia. A UCLA
press release tells us matter-of-factly that the “microorganisms”
are 3.465 billion years old. The UCLA press release does not
mention any controversy about whether these tiny things were
microorganisms.
But researching how the
story was covered on other news sites, I find there is quite a bit of
controversy. For example, an article on LiveScience tells us that
“other researchers have cast doubt on whether these sediments house
traces of life at all, suggesting that chemical markers thought to
represent biological evidence were the result of geothermal
activity.” The same article says, “Billions of years of geologic changes leave behind chemical traces in rocks that often resemble
signatures of biological remains, according to previous
studies.”
A scientist has used some
fancy new technique to analyze these geological specimens. Some new gizmo was created
to analyze the specimens, but it sounds like possibly unreliable
“bleeding edge” technology; the UCLA press release calls it
“cutting edge technology.” “It took us 10 years to develop
the ability to make these measurements accurately," said one of
the scientists.
But Science magazine tells us the following:
[Rasmussen] is
concerned that the microfossils may have been badly preserved. Olcott
Marshall, who thinks the rock impressions are not fossils at all, but
the product of geological processes, is even more critical: “The
errors produced by this analytical technique are so large” that the
data are not clear enough to say there are different types of
microbes in rock, she says.
We
learn from the UCLA press release that the scientist making the claim
that these microscopic geological specimens are 3.465
billion-year-old and are microfossils is a scientist named J.
William Schopf, who has published several papers on these specimens
over the course of 25 years, since 1993. He's apparently one of the
scientists who spent 10 years working on these little specks. We may wonder whether someone with such a large investment
of time in these speck specimens may be biased in his examination of
them, more prone to regard them as biological than the evidence
warrants.
Schopf's
latest conclusions are based on an analysis trying to use radioactive
dating to date microscopic specks. The problem with that is while
radioactive dating may be reliable when used to determine the age of
a skull or a big dinosaur bone, when you try to use radioactive
dating on some microscopic specks, radioactive dating isn't terribly
reliable – hence the previous quote that
“errors produced by this analytical technique are so large.”
The
latest work on these alleged microfossils should have been announced
with the appropriate caution, with a headline such as “Debate
Continues on Whether Australian Microscopic Traces Are Fossils.”
But instead our UCLA press release has done the opposite. Not only
has the UCLA press release hidden the scientific controversy, but it has
announced, most absurdly, that these microscopic traces of an
uncertain nature “indicate that life in the universe is common.”
Schopf
claims that his research “tells us life had to have begun
substantially earlier and it confirms that it was not difficult for
primitive life to form and to evolve into more advanced
microorganisms.” No, his research tells us no such thing. The age
of the earth is believed to be 4.6 billion years old. Finding a
microscopic fossil about 3.5 billion years old tells us nothing about
how hard or improbable it was for primitive life to form.
Even if it were true that life on Earth arose 100
million years after it first had the opportunity to arise, this would
not be a strong reason for thinking that life in the universe is
common. Consider this case. You open your new pastry shop one day,
and within an hour someone comes in trying to order a pizza. The
chance of this happening is very low. You would be mistaken if you
reasoned that the chance of such a thing happening must have been
high, or else it would not have occurred within the first hour of
your shop being open. You are not entitled to draw such conclusions
based on the timing of a single occurrence.
The
article here
states the following by MIT professor Joshua Winn (referring to this
scientific paper):
There is a commonly
heard argument that life must be common or else it would not have
arisen so quickly after the surface of the Earth cooled," Winn
said. "This argument seems persuasive on its face, but Spiegel
and Turner have shown it doesn't stand up to a rigorous statistical
examination — with a sample of only one life-bearing planet, one
cannot even get a ballpark estimate of the abundance of life in the
universe."
This
announcement may end up rather like the “Life on Mars” affair of
the 1990's, when some scientists announced with great fanfare that some meteorite that
supposedly had come from Mars had evidence that life had existed on Mars.
The evidence consisted of marginal specks like the Australian
specimens Schopf has studied. In the subsequent years this claim
ended up being mainly rejected by other scientists.
Hyped-up science press releases often are like this
No comments:
Post a Comment