Some Basic Considerations:
(1) Population: If an organism has more born offspring than parents, then the
population will increase.
(2) Resources: If the available resources needed for an organism to survive
doesn’t change, then, as the population increases there will come a time when the resources available will not be able to support all the population at the same level as before.
(3) So: At this time the population will experience a lowering of the
“standard of living” for the whole population or certain part of the population will use a greater portion of the resources than another part.
Eventually there comes a point where the “standard of
living” is so low that life is not possible for all.
Some will likely be more able to use a greater share of the resources
and live long enough to produce surviving offspring and others will not.
The factors that will determine the survivors is one of the main
concerns of evolutionary scientists.
This is the logical basis of Evolution and Natural Selection.
==========================================================
Some broad factors that determine who lives:
– Environmental Factors: Examples: Climate and weather changes that
affect things like food sources, predator population, parasites, disease, social
conditions.
You can likely think of other Examples.
– Environmental Accidents: Examples: Organism happens to be in places of
unexpected dangers such as volcanoes, hurricanes, earthquakes, meteor strikes,
landslides, floods, wars by other species, wars within a species. Some
call this luck. Again you can think of other Examples.
– Genetic makeup of the organism.
If the environmental conditions are the same for all, then the genetic makeup
of an organism becomes the dominant factor. Those with the appropriate
genetics to be able to cope better in that environment and can produce offspring
that will live long enough to produce offspring that will live long enough to
produce their own offspring will be what is called “the
fittest”.
The selection of organisms that cope and reproduce through the generations will
result in organisms with genetics that become better adapted to their
environment. Those that have the genetics to cope with changes in the
environment will also have a better chance of surviving.
For natural selection to work requires variation in the genetic makeup of the organisms,
so that the organisms aren’t all the same. These variations produced in numerous
ways are called mutations.
This applies to all organisms from viruses and bacteria to plants and
animals, including humans.
Knowing all this, Humans have the potential to change the environment and
genetics to control evolution and not be a total slave to it.
Artificial selection in domesticated animals and plants is an example of
this control.
Because of the 3 basic considerations mentioned at the beginning, anything
that reproduces, and where there are limited resources would be subject to
evolution and natural selection. Some possibilities: To Life
anywhere (on earth or anywhere else life may be found), to galaxies, to
universes. You can think of other possibilities.
Evolution and Natural Selection are inevitable.
A simple example of the first 2 basic considerations:
In most species the population tends to increase exponentially — this is
limited drastically by the resources available to the species — the resources
tend to be constant. This is where genetics makes a difference. The
following assumes a couple will have 4 children in each generation. Also
the following assumes that the parents die as soon as offspring are born — in
other words this is a very, very conservative example of the power of population
increase compared to resources — shows how quickly evolution can come into
play..
| Generation | Population
(Assuming a simple doubling — usually it is much more) |
Constant Resource (to sustain 1000 organisms) | Assume constantly increasing resources (not realistic in most cases) |
|
| 1 | 2 | 1000 | 1100 | |
| 2 | 4 | 1000 | 1200 | |
| 3 | 8 | 1000 | 1300 | |
| 4 | 16 | 1000 | 1400 | |
| 5 | 32 | 1000 | 1500 | |
| 6 | 64 | 1000 | 1600 | |
| 7 | 128 | 1000 | 1700 | |
| 8 | 256 | 1000 | 1800 | |
| 9 | 512 | 1000 | 1900 | |
| 10 | 1024 | 1000 | 2000 | This is where Natural Selection would kick in for constant resources |
| 11 | 2048 | 1000 | 2100 | |
| 12 | 4096 | 1000 | 2200 | This is where Natural Selection would kick in for increasing resources. |
| 13 | 8192 | 1000 | 2300 | |
| 14 | 16,384 | 1000 | 2400 | |
| 15 | 32,768 | 1000 | 2500 | |
| 16 | 65,536 | 1000 | 2600 | |
| 17 | 131,072 | 1000 | 2700 | |
| 18 | 262,144 | 1000 | 2800 | |
| 19 | 524,288 | 1000 | 2900 | |
| 20 | 1,048,576 | 1000 | 3000 | |
| 21 | 2,097,152 | 1000 | 3100 | |
| 22 | 4,194,304 | 1000 | 3200 | |
| 23 | 8,388,608 | 1000 | 3300 | |
| 24 | 16,777,216 | 1000 | 3400 | |
| 25 | 33,554,432 | 1000 | 3500 |
Evolution is determined (natural selection designed) by the
environment and the also the laws of Physics and Chemistry and is also dependent
on chance happenings such as mutations.
O. Hooge, B.C., Canada
Naturalism and Religious Experience 