2. SALIENT POINTS
• Life is created by a supreme being
• Brahma (Hinduism)
• God (Christians, Jew, Muslims)
• Creationists believe that the current form of
species is the same as the original form that God
created
5. How did life start on Earth? When did it start?
These questions remained mysteries for thousands
of years of human history. We know that the Earth
is about 4.5 billion years old and that bacteria
could be found on Earth as early as 3.5 billion
years ago. The theory of evolution provides us
with an explanation with how life started from a
single celled bacteria and diversified to the millions
of species of animals, plants, fungi, and bacteria,
but where did the first single cell come from?
6. Abiogenesis is a scientific
theory which states that life arose
on Earth via spontaneous natural
means due to conditions present
at the time. In other words, life
came from non-living matter.
7. Primitive Earth
Imagine a lifeless Earth - violent volcanoes, lightning
storms, nearly boiling oceans, frequent earthquakes, and
an atmosphere with high levels of toxic gases! Primitive
Earth 3 to 4 billion years ago was like that! Imagine an
Earth where the air consisted of high concentrations of
methane, ammonia, hydrogen, and vaporized water.
So how and why did life start under these conditions?
In the early 1950's this question was debated by scientists
looking for a coherent answer to this important question.
8. The Miller Experiment
In 1953 Stanley Miller sought out to answer the question
of the origins of life on Earth. In his experiment he used an
apparatus with a flask filled with water and chemicals thought
to exist on primitive Earth. What he found was these
chemicals under the right conditions spontaneously formed
organic molecules! This experiment suggests that organic
molecules could have spontaneously formed on primitive Earth
giving way to the first living things.
9. The Miller Experiment
Some scientists do not think the conditions of the
Miller experiment were accurate to those on primitive
Earth, but subsequent experiments with altered
atmospheres have shown similar results of the
spontaneous generation of amino acids, lipids, and
nucleotides.
10. It Started with RNA
For years it was debated among scientists if DNA, RNA, or proteins came
first. DNA serves as the principle means to store genetic information, and proteins
can catalyze reactions. RNA is nucleic acid that all living things have. It can act as a
genetic library like DNA and can catalyze reactions similar to proteins. This ability
makes RNA the ideal candidate to have started the first life on Earth.
So where did RNA come from? Can RNA spontaneously form? First let us
review the structure of RNA. RNA is composed of four nucleotide bases:
• adenine (A)
• guanine (G)
• cytosine (C)
• uracil (U)
11. It Started with RNA
These four nucleotides are the building blocks of
RNA. If they can be synthesized spontaneously given
the conditions on primitive Earth, then a large piece of
the puzzle of how life started has been solved. Recently
it was found that certain molecules can form all four
RNA nucleotides in the presence of ultra violet light
(sunlight).
17. SALIENT POINTS
• modification of the Creation Theory
• several living creations each encountered a
catastrophe which completely destroyed them
• each new creation consisted of new life forms
different from the previous ones
