| Evidence
from Molecular and Cellular Biology
Beginning
in the 1950's, advances in technology have allowed scientists
to "see" life at its smallest levels, that
of macromolecules and cells. While their description
and understanding of cellular systems is by no means
complete, what has been determined to date shows a stunning
complexity that vastly exceeds anything in the inanimate
world. All life is cellular from single-celled organisms,
such as bacteria and yeast, to multi-celled organisms
with trillions of cells. The subject matter of biological
evolution is cellular life. Any theory that claims to
know how life in all its diverse forms came into existence
on earth should be able to back up that claim with verifiable
experiments and calculations. To what extent has biological
evolution been successful in doing that?
In
order to answer that question, consider an evolutionary
staircase starting with the macromolecules of life at
the bottom, single-celled organisms higher up, multi-celled
organisms higher still and ending with human beings
out of sight at the top. We will judge the efficacy
of evolution by its ability to explain in a scientifically
verifiable way how each step came into existence.
Step
1: Macromolecules; proteins, DNA, RNA
Fifty years of experiments to show how these macromolecules
evolved have not been successful. While scientists have
been successful in determining how an evolutionary process
could have made amino acids, the building blocks of
proteins, they have been unable to determine how they
join to form proteins. Their success with RNA and DNA
has been even less since they have been unable to determine
how their building blocks, nucleotides, came into existence.
Cells use complex processes to make their macromolecules,
including the use of many enzymes, which are large,
complex proteins.
Step
2 and Higher: Cellular Organelles and Processes
Organelles are complexes of many molecules that reside
in eukaryotic cells and have specific functions. Some
of the cellular organelles are the nucleus which contains
the DNA, mitochondria which provide the cell's energy,
ribosomes which assemble proteins, and lysosomes that
degrade used molecules and organelles. Scientists do
not know how these or any other cellular organelle obtained
its form or function.
Cellular processes involve the cooperation of many molecular
machines and organelles for a specific purpose. They
are too numerous and varied to enumerate. Some examples
are the following: the synthesis of the cell's proteins,
DNA, RNA, lipids and carbohydrates. (The making of these
biomolecules entail different processes.); the synthesis
of the cell's organelles; the transport of materials
within the cell by molecular machines; the conversion
of glucose to a chemical fuel for powering biochemical
reactions; high blood sugar triggering the release of
insulin by the pancreas; and steroid hormones signaling
cells to produce certain proteins. Scientists do not
know how these or any other cellular process came into
existence.
Step
(Higher still): Scientists do not know how cells came
into existence.
Step
(Very much higher): Multi-celled Organisms
Multi-celled organisms add a whole layer of complexity
to that of single-celled organisms. They contain hundreds
of different kinds of cells, all of which differentiated
from identical embryonic cells. They form a variety
of tissues which comprise the complex organs of multi-celled
organisms: blood vessels, skin, skeletal muscle, liver,
kidneys, heart, eyes, etc. The various tissues interact
and communicate via chemical messengers sent through
the blood and electrical impulses sent along connecting
nerve cells. The astounding number and variety of processes
occurring all the time are balanced and controlled so
that the organism remains viable. Scientists do not
know how multi-celled organisms and the processes unique
to them came into existence.
In
short biological evolution has failed to account for
the existence of any aspect of cellular life.
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