Natural Selection - The Process

Natural selection

The process

     After a few billion years of natural selection some generalizations regarding the process can be made. When exposed, these generalizations seem obvious because they are observable extensions of other familiar natural processes which also guide nature’s many experiments.

• Natural selection requires continual deviations from pure strains
• Natural selection filters toward complexity   
• Natural selection filters toward accelerated selections
• Natural selection can be focused or expanded by environmental changes.
• Natural selection filters toward advances in awareness

     The selection of a new characteristic requires at least two different attributes from which to choose and a standard of measure against which they can be tested. Neither of these conditions are purposeful arrangements. Physical environments are random arrangements endlessly diverse and ever changing. Add to this physical complexity, the living half of an environment, including predators, parasites, essential foods etc. and the complexity of the total environment against which our two choices are to be tested becomes extreme. Tested against such complexity the odds are that if only two options are offered, both options will fail. Increase the number of attributes to be tested, from two to a very large number with extreme diversity, and the odds of a successful selection are greatly improved. Natural Selection functions effectively only when the diversity of the natural environment is challenged by an equally diverse array of living attributes from which to choose. A single strain in a static environment will never change, and a pure unchanging strain challenged by a changing environment will not survive.

     The simplest pieces of reproductive matter gave birth to the simplest of living cells. Anaerobic bacteria thrived for several billion years in earth’s early hostile acidic, hot, methane environment as life’s first and only kingdom. As the earth cooled, cyanobacteria, blue-green bacteria, emerged and transformed the earth’s atmosphere from 1% oxygen to 20% oxygen through a process known as, oxygen eliminating (excreting), photosynthesis. The chemical transformation of a planet’s entire atmosphere by a microscopic life form is not only amazing in its scope but also in its results. Without this atmospheric transformation there would be no ozone layer, no life on land, and the other four living kingdoms could not have evolved. This first kingdom of early single celled life is recorded in sedimentary rocks and as fossilized stromatolites. Blue-green bacteria are alive today and, along with a few surviving anaerobic bacteria, are life’s longest persisting living form.

     Kingdom 1, Prokaryotes, (bacteria), still live around us, on us and in us, in extreme numbers. There are over 10,000,000,000 in every spoonful of garden soil and they comprise a significant portion of the dry weight of all animals. Over 10,000 species of bacteria have been identified and there are many more. Bacteria continue to play a significant role in Earth’s biosphere, including the chemical composition of the atmosphere. They also provide essential symbiotic survival relationships for most plants and animals, including man, and are both the cause of, and the basis for cures for, many diseases and are themselves subject to viral infections. All bacteria belong to the kingdom prokaryotae, (monera). Early bacteria lacked a well formed cell nucleus and reproduce asexually by simple cell division, (mitosis). Bacteria were the only life form for more than half of the history of the Earth and begin to leave a fossil record 3.4 billion years ago. With extreme numbers of bacteria being tested in an ever changing physical environment over such a long period of time, one might expect a proliferation of other types of living forms, but natural selection continued to test only bacteria for two million years, produced hundreds of identifiable species but did not jump to more advanced forms of life until cyanobacteria began transforming the atmosphere 2 billion years ago. With the advent of a new oxygen rich atmosphere, natural selection took advantage of the new environment and cells with a nucleus quickly evolved. From these eukaryotic cells, multi cellular life emerged and the process of natural selection accelerated.

     (Kingdom 2), Protoctistae; the first multi cellular forms, (protozoa, aquatic kelp, slime molds and molds), began their line of natural selection about 1.2 billion years ago and persists today with 27 phyla and thousands of species.         

From kingdom 2 the other kingdoms developed; (Kingdom3); Fungi   ( Kingdom 4); Animals,  and (Kingdom 5); Plants. Each began their separate lines with the earliest evidence for aquatic animals appearing about 700 million years ago and the earliest land plants and fungi appearing about 470 million years ago.

     Today nearly all animals are aquatic and worm like with only two of the 33 primary phyla truly adapted to living on the land, (chordates and arthropods). Thousands of species of animals exist today in these two phyla and tens of thousands of species have arisen in all of the animal phyla with most now extinct. Plants have fewer phyla with only 10 but have tens of thousands of species. Fungi have been divided into only 5 phyla but also have thousands of different species. The large numbers of species in the five kingdoms attests to a natural divergence from pure genetic strains and the augmentation of diversity by the natural selection of variant forms. The increased complexity of later species attests to a natural trend toward complex forms including increases in awareness.    

     The selection of the ever increasing complexities associated with cilia, flagella, fins, legs and wings attests to natural selection’s tendency to select the more complex. Likewise, selections of complex manipulative apparatus, such as mandibles, beaks, tentacles and hands help to insure a life form’s future through the use of natural tools. The interactions of predator and pray have led to the natural selection of complex weapons like fangs, claws, and poisons and complex defenses like body armor, improved sensory warning systems, and natural antidotes. Complex sensory and neurological systems have also been naturally selected as small incremental increases in awareness provided a slight edge for survival in changing environments and in competitions with other evolving forms. Natural Selection appears to have rejected the path of “keep it simple and stupid” in favor of a path to, “the complex and smart”.

     For the first two thirds of life’s four billion year history, life evolved at a very slow pace. The natural selection process was in low gear because the environment was somewhat static. Only the oceans supported life and proto genetic forms had produced only single celled creatures. Natural selection also remained slow because there were few new attributes to be tested and environmental tests varied only slightly. There are several theories as to what shifted natural selection into second gear. One; that the prodigious success of anaerobic single cells multiplying at an arithmetic rate breathed up most of the methane and carbon dioxide in the atmosphere and exhaled so much oxygen that they poisoned themselves, created a new atmosphere and opened the door to a new type of cell that used oxygen and exhaled carbon dioxide. Another theory is; that the entire Earth became frozen, that the ice absorbed most of the carbon dioxide in the atmosphere and when it thawed, millions of years later, because of volcanic activity, the carbon dioxide was retained by being absorbed in the melt water. With the ice and most of the carbon dioxide gone the earth presented a new and more complex environment that spawned new and faster developing life forms.

     Whatever the actuality we can verify the acceleration of natural selection by examining fossil records. Natural selection was slow when mitosis (simple cell division) was the only reproductive method and the biosphere was relatively stable. The advent of gene sharing introduced sex and death simultaneously and increased the number of variant genetic combinations exponentially. Instead of waiting for an anomaly to occur in the static genetic arrangements of single cells, gene sharing produced new genetic arrangements with every swap. Natural selection requires large numbers of potential selectees to find adaptations that improve survivability and pass on modified codes. Codes carried forward by variant forms carry within them the tendency for even more variant forms and thus accelerate their production. In this convoluted way, gene sharing, (sex), caused an explosion of variant forms to run through the natural selection process. New forms soon found suitable niches in nature’s environmental offerings and continued their own genetic combinational experiments to create an even greater pool of variants. The proliferation of new forms also added to the complexity of the biophysical testing ground and opened many new corners into which new variants could benefit from even small advantages. New forms generating new forms are selected more frequently because the environment becomes more diversified as they are added. The result of all of these new combinational possibilities was, and continues to be, a constant push on natural selection’s accelerator.

     Natural selection favors genomes with tens of thousands of genes and millions of alleles because they are prodigious variant producers. The preference by natural selection for large numbers of alleles in genetic structures, (the unit of transfer for physical characteristics), also applies to the selection of advanced aware states through an increase in meme choices, (the unit of transfer for acquired responses). The pace of natural selection accelerates with success, and this tendency has contributed to both the accelerated development of awareness and physical forms.