This week's lecture is given by Geoff Marcy, someone you've perhaps never
heard of, but only proving once again that you can only be famous if people
have
heard of you.
Nonetheless, Marcy has discovered more planets than Galileo ever dreamt of,
and as a result of his and his colleagues extraordinary work, he recently
shared the $1 million Shaw Prize. The Shaw Prize was extablished by the Hong
Kong
businessman, Sir Run Run Shaw, to create awards equivalent to the Nobel Prize,
but in those areas of investigation where no Nobel Prize exists: biology,
astronomy and mathematics. The Shaw Prize has been awarded for only two years
now,
and Marcy, along with Michel Mayor of the Geneva Observatory, were awarded
the prize in astronomy last year.
Although the subject of Marcy's talk is nominally astronomy, it is also
hardcore biology, even if it is at a very primitive state. Geology was the
science
that informed and transformed evolutionary thought during Darwin's time.
Comparative planetology will do the same during ours. The questions that will
dominate this coming century are: (i) is life inevitable?, (ii) is it fragile?,
and
(iii) to what degree does the evolution of complex life depend on the good
fortune of specific planetary configurations of remote solar systems?
I've written before that I've always found it discouraging that people so
readily say that biology (or ecology) has no laws. It's simply not true, even
though Marcy says much the same thing in this lecture. When we do find life on
other worlds, it will almost certainly be true that it's biochemistry will be
different than our terrestrial biochemistries, perhaps anchored in a different
part of the periodic table, and almost certainly using a completely different
information-bearing schema than DNA/RNA. It will however inevitably still be
subject to Darwinian selective constraints, and thus must exhibit all of the
"laws" and constraints that we see in the ecological patterns we find here on
Earth: logistic curves, predator-prey population cycles, competitive
exclusions,
niche partitioning, species-area curves, nestedness, and so on.
Ecology studies the grand patterns of life, not the minutia, and those grand
patterns should be common throughout the universe.
Wirt Atmar
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The Evolutionary Biology Lecture of the Week for May 29, 2006 is now
available at:
http://aics-research.com/lotw/
The talks center primarily around evolutionary biology, in all of its
aspects: cosmology, astronomy, planetology, geology, astrobiology, ecology,
ethology,
biogeography, phylogenetics and evolutionary biology itself, and are
presented at a professional level, that of one scientist talking to another.
All of
the talks were recorded live at conferences.
This is the second lecture in a summer-long series on the new science of
astrobiology.
=====================================
May 29, 2006
Part II: Astrobiology
Exoplanets, Yellowstone, & the Prospects for Alien Life
Geoff Marcy, University of California, Berkeley
52 min.
"It will be especially interesting to see whether it is astronomy
that absorbs biology, or the other way around."
-- Fred Hoyle (1915-2001)
The beginnings of formal Western science can be traced back to a single point
in time: the life and work of Copernicus (1473-1543). His major work, De
revolutionibus orbium coelestium, was published in the year of his death, after
more than three decades of thought. "The Copernican Principle" is the
philosophical statement that no "special" observers need or should be proposed
to
explain our position in the heavens.
Bruno, in 1584, explained the principle in this fashion:
"Thus the earth no more than any other world is at the centre; and no
points constitute definite determined poles of space for our earth, just as she
herself is not a definite and determined pole to any other point of the ether,
or of the world space; and the same is true of all other bodies. From various
points of view these may all be regarded either as centres, or as points on
the circumference, as poles, or zeniths and so forth. Thus the earth is not in
the centre of the universe; it is central only to our own surrounding space.
Although we have greatly expanded the reach of the idea, we still conduct our
science by this same principle: that the laws of physics and chemistry are
the same everywhere, and we now call the general thought the "Principle of
Mediocrity."
If this is so -- and after 400 years of observation and investigation, we
have no reason to doubt it -- then we cannot believe that there is anything
special about the Earth or the life that inhabits it. If one earth exists, then
there must be many.
The first extrasolar planet was discovered in 1995 by Michel Mayor and Didier
Queloz of the Geneva Observatory, but we deeply believed in the existence of
these planets long before their recent discoveries.
Mayor and Queloz's finding was soon confirmed by the team of Marcy, Butler,
Fischer and Vogt and then greatly expanded upon. Marcy and colleagues have
since discovered more than 110 planets. But in the intervening years since
1995,
we have been surprised by the diversity of the types of solar systems we've
found.
In September 2005, Geoff Marcy and Michel Mayor were awarded the $1 million
Shaw Prize for their revolutionary discoveries. In referencing his award, Marcy
said:
"We now know that other planetary systems exist, but that their
diversity renders our solar system just one type of many. The odd orbital
shapes
caused by the gravitational scattering of planets by other planets makes our
solar
system relatively peaceful by comparison. Perhaps life owes its existence here
on Earth to the fortuitous, delicate arrangement of the planets in our
system.
What does this imply for the prospects of other life in the universe? We
truly don't yet know. The detection of other Earth-like planets remains beyond
our
current technologies, but as you will hear in the coming lectures, that may
soon change."
Marcy, like almost everyone else at the moment, expects that bacterial life
should be common in the universe, but he is quite pessimistic about the
presence of technological, "intelligent" life anywhere near us. Every
observation of
the night sky for the last two hundred years has been one more negative
affirmation its nearby absence.
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