Thursday, March 25, 2010

The world of co-evolution

By Steve Rensberry

Biology, as I understand it, is broadly defined as the study of living organisms and classifies all living things into five major groups: plants and animals, fungi, plant-like, one-cell organisms, and monera (bacteria). Identified are more than 1.2 million animal species, 300,000 plant species and 100,000 other forms of living organisms. Biochemistry, defined as the chemistry of living organisms, looks at the compounds, forces and biosynthesis occurring within such organisms.

When it comes to humans - of which there are now about 6.8 billion of us - water molecules are the most abundant compounds. Other major biomolecule categories include acids, bases and salts or electrolytes; proteins or "macromolecules" composed of amino acids; carbohydrates - known as sugars and starches; lipids - which includes fats and many other insoluble organic biomolecules; and nucleic acid compounds - referring primarily to human DNA or deoxyribonucleic acid.

Each compound's unique characteristic is what make the whole process function. Water provides a non-dry environment necessary for the thousands of chemical reactions that need to occur. Electrolytes are considered essential in their ability to conduct electric current. Carbon-containing proteins, which are enormous molecules often linked to peptide bonds, perform hundreds of different functions. One class of proteins, namely enzymes, catalyze reactions through uniquely shaped surface areas (binding sites or receptors), which bind to ligands or a substrate (a complementary-shaped molecule or ion), consequently changing the substrate into a different compound entirely.

Proteins often serve as communication agents and chemical messengers, or transporters of such things as oxygen to various cells - all of which cause the cells to begin some kind of activity. Carbohydrates, such as sugars, saccharides, polysaccharides and disaccharides, enable the body's need to release and store energy on the biochemical level.

Lipids, such as saturated and unsaturated fatty acids, serve as concentrated energy sources. Other lips like steroids form male and female hormones, as well as cholesterol. Still others include prostaglandins which are involved in hormone functioning, and phosphoglycerides (lecithin), a major constituent of the membranes of cells and important for many other cellular functions.

Nucleic acids, namely deoxyribonucleic and ribonucleic acids, exist as polymers of thousands of smaller nucleotide molecules. One human DNA molecule is composed of a polynucleotide chain of more than 100 million pars of molecules held together by hydrogen bonds. The sequences are different for each human individual, but the same for each cell within any one individual's body.

How the body uses the food it consumes is what we refer to as metabolism and involves the bioenergic process of catabolism (chemical bond decomposition reactions), and anabolism (a chemical reaction which combines molecules into one which is more complex).

So there you have it, a summary I wrote a while back in my search for that elusive fountain of youth. For the record, I’m still on the hunt.

Anyway, there’s an interesting proposition put forward by Ian Marshall and Dana Zohar in their book “Who’s Afraid of Schrodinger’s Cat?” (William Morrow, New York, 1997, pgs 93-94). They ask the question: Is it possible that evolution could occur on the level of DNA?

In particular, the authors suggest that the concept of co-evolution could be at work on the molecular biology level, resulting in the transformation or evolving of DNA structures themselves in cooperation between mutually benefiting organisms.

Co-evolution is described as a process which considers the interdependence and symbiotic relationship between animals and plants, in contrast to the competitive nature of Charles Darwin’s evolutionary theory.

And to think, all this time while some of us have been waiting for the next big evolutionary leap to come along - and perhaps erase one of the umpteen many debilitating diseases that plague our species - a process of change may very well have been going on all long right under our noses.

Carl Sagan on God, Faith and Religion