Biology Of Earth
Sometime during our lives, we've questioned
ourselves at one point just how long
has the earth existed and how did life
begin? Our Biology book written by:
Solomon, Berg, and Martin, shows
theories that has taught us that earth is
approximately 4.6 billion years
old, and the earliest pieces of life form found
was dated back to
approximately 3.8 billion years old. This only leaves a time
space of 800
million years between the formation of earth and the creation of
life. Since
then, new theories have shown that life may have originated earlier
then they
thought. From Bernstein, Sanford, and Allamandolas' article,
"Life's
Far-Flung Raw Materials" comes the theory that only about 100
million years
after the earliest possible point for earth to support life,
evidence shows
that organisms were already flourishing. But with the amount of
time between
this, it almost seems impossible, but not if something were to help
the
process like space compounds. Christopher Chyba has the leading idea
that
these space particles did in fact bring in the planet's water and
atmospheric
gases. These space organisms are thought to be responsible for
making our earth
habitable by bringing in water and gas molecules which would
provide our
atmosphere and oceans. Also, that the space debris was needed to
build life and
could have even started the first cellular processes. These
space molecules
could have absorbed UV-rays from the sun, helping out the
weaker molecules, and
converting the light energy made into chemical food,
which is essential for
photosynthesis. Miller showed that the planets first
single celled organisms
came from a process of chemical steps which is
possible for the building blocks
of life. It is stated that everyday, tons of
space dust falls to the earth's
surface, some found containing 50% organic
carbon, bringing in about 30 tons of
organic material. So not only do some
scientists argue about space particles
bringing in water and gases, but they
could also bring in
"ready-made-organic molecules such as the ones seen
today. From the
meteorites that hit the earth they were able to find a
variety of 70 amino
acids, but only 8 are used by living cells to build
proteins. These meteorites
also show such compounds including: nucleobases,
ketones, quinones, carboxylic
acids, amines, and amides. Astronomers have
seen a variety of these organic
compounds in the universe and more abundantly
in clouds. An experiment was done
in a laboratory by Allamandola, where he
developed a cloud containing such
compounds seen in meteorites. This provided
more evidence towards the theory of
the earlier development of earth. With
the presence of such extraterrestrial
compounds like amino acids, quinones,
amphiphilic molecules, and other organics,
could have very well made it
possible for the development or helping towards the
development of such life
processes. In conclusion, it is easier for us to
believe that
extraterrestrial compounds were present during the time of this
evolution and
that it inhibited the creation of such living organisms. But since
this
concept is relatively new there is not enough evidence to determine if
such
compounds had anything to do with the development. Why couldn't one say
that the
scientists misinterpreted the development of earth and living
organisms all
together? This assumption could regenerate all new findings as
to when and how
the earth
began.