Life Essay, Research Paper
Until recently, scientists believed that the sole source of
energy responsible for life on earth was the sun. In 1977, a
group of scientists researching the theory of plate tectonics,
traveled to the floor of the equatorial Pacific Ocean and
discovered something that could possibly explain how life
began on this planet. From the Galapagos Rift’s thermal
springs, scientists discovered densely populated communities of
several species never before observed. Since that time the
Federal Government has devoted more than 10 million dollars
to research these communities and their evolutionary history.
This figure, to many scientist’s dismay, is dramatically less
than that of the space exploration program’s budget. For
example, in 1992, the government budget for oceanography
research was $600 million while NASA spent 8.5 billion. We know
more about the space around us than we do about our own
home. Only 1 percent of the sea floor has been mapped. The sea
is the largest, most inaccessible, and least understood
ecosystem on this planet.
Since studies of these communities began, previous notions
that cold darkness, and extreme pressure are inimical to life
have been disproved. We now know that an ecosystem can be
sustained by unusual energy sources. The animals that have
been discovered in hydrothermal vents are fascinating as well
as extremely important. The structure of these creatures is
such that a new kingdom has been discovered/created.
Previously scientists divided the living world into two
kingdoms: bacteria, also known as prokaryote and
eukaryotes (plants and animals). The difference between the
two kingdoms was their genetics. The DNA of these newly
discovered animals was distinct from the two other kingdoms.
They have been called archaea. Research on these animals is
limited since they do not grow and culture well in a
laboratory. These animals live in extremely hot temperatures
of 160 degrees Fahrenheit and higher, while microbes have been
found living in boiling water. This revelation surely must
change all of the "rules" we have for health standards. These
newly discovered facts must dramatically change the way we
think of life on earth.
Living in these vents are entire communities of
invertebrates: tube worms, mussels, clams, and even shrimp. In
the absence of light and without the photosynthesizing
plankton that provide most sea life with food, these animals
have an alternate way to live. These invertebrates have
formed symbiotic relationships with the bacteria living with
them. The mechanics of this relationship are incredibly
interesting. Bacteria thrive on sulfide which is found in vent
water (hydrogen sulfide). They use the sulfide’s chemical ene
to produce organic carbon compounds similar to how plants
use solar energy in photosynthesis. The bacteria employ
chemical rather than light energy to transform inorganic
carbon to organic compounds. This process is called
chemosynthesis, and was at first thought to be a rare
phenomenon. The invertebrate houses the bacteria and
provides chemicals needed for the process of chemosynthesis.
The bacteria in turn gives organic carbon compounds to the
invertebrate, which keeps the invertebrate alive, (so it expends
little or no energy gathering its own food). An example of this
type of tubeworm can be found in vents along submarine
mountain ranges off of the western coasts of Mexico and
South America. One in particular, at a site called the Rose
Garden in the Galapagos Rift is long and white with a luminous
red plume. Upon examination it was discovered that these
worms have no mouth, stomach, or digestive system. They
survive by extending their plume into the vent fluids absorbing
numerous compounds including sulfide which are turned over
to the bacteria. The bacteria then provide food to their host.
The existence of this symbiotic relationship between an
invertebrate and a bacteria is as incredible as their existence.
Another feature of this relationship is their mutual dependence
on oxygen. Oxygen is an element required by the vent bacteria
to perform its essential role. Interestingly, this is one of the
few ways these communities are tied to the world away from
the vent.
The implications of this awesome discovery are providing
us with leads, clues, and suggestions to where life began and
where it is going. From biotechnology that can be used in
tracing fingerprints in a crime scene, to discovering where life
begun, this great new breakthrough will immensely enhance
our understanding and comprehension of our life and our
environment. We do not yet know where this new information
will lead us, as our knowledge as well as our funding and
perhaps even our imagination is limited. We once thought the
earth was flat, ancient man thought that lightning was from
an angry g-d, and until recently scientists thought that life
without sunlight at the bottom of the ocean was impossible, so
we are left with an incredibly complex universe to study,
starting with our planet.
REFERENCES
"Clues to Fiery Origin of LIfe Sought in Hothouse MIcrobes"
by William J. Broad The New York Times May 09, 1995 V144,
pB7(N), pC1(L), col 5, (48 col in.).
"Depths of Ignorance" by Cindy Lee Van Dover. Discover
September 1993 V14, n9, p. 37(3).
"Hydrothermal-Vent Communities of the Deep Sea" by
Verena Tunnicliffe
American Scientist July/August 1992 V80, n4, p.336(14).