5. From Bacteria to Human Beings (1)

Suppose simple life forms exist on a life-supporting planet. How could these develop into more complex life forms and ultimately into human beings? This was the focus of Darwin ’s theory in The Origin of Species. He claimed (as evolutionists still insist) that, given enough time, more complex life forms evolve merely by chance and natural processes. Now – 150 years later – has modern science discovered the mechanisms that made this happen? Have intermediate species been found that support the model? Or does the evidence point the other way?

The evolutionary textbooks offer various examples of “evolution” within species as proof of their theory. These include the beaks of finches, fruit flies, and bacteria resistant to antibiotics.  But are these genuine examples of evolution? To get a better grasp of the process that makes these changes occur it is necessary to understand the difference between changes of characteristics within the same species and changes that transform one species into another species. These two kinds of changes, respectively called natural selection (or also survival of the fittest) and genetic mutations proof to be quite different.

Darwin and the Survival of the Fittest

Traditional evolutionary theory – also called Darwinism – considers natural selection the driving force behind evolution. It is the observation that individual organisms with favorable characteristics are more likely to survive and reproduce than those lacking these traits. As a result, subsequent generations are largely comprised of the organisms with favorable traits, so these traits will occur more and more. After a number of generations, all organisms will have the favorable traits and those without them will have died out. Hence, natural selection is also a survival of the fittest, as Darwin liked to call this process.

What led Charles Darwin to natural selection? Darwin’s research was based on breeding. He himself was an active breeder of pigeons and vigorously researched the principles behind breeding, which he called controlled selection. This combined with his observations of unusual variations in animals on the Galapagos Islands in South America . while traveling on the HMS Beagle in the 1830s lead him to his theory of natural selection.

One of his most famous illustrations from The Origin of Species has come to be known as Darwin’s Finches, and it is still used in most evolutionary textbooks. Darwin noticed that the beaks of the Galapagos finches were shaped distinctively different than those of finches in England . The Galapagos beaks were longer and more pointed. He concluded that the sustained periods of drought and the rocky terrain of the islands were such, that only finches with long beaks could survive.  To secure food, these birds had to dig deeper into harder soils than the finches in England . So he reasoned that finches with short beaks on the Galapagos would not last long.  After natural selection through numerous generations, only a population with the longer, more pointed beaks could remain.

There is Much Confusion on How Natural Selection "Impacted" the Evolution of a Species?

There are many other illustrations of natural selection. For instance, today there are as many as 200 breeds of dogs. Did you know that most of these breeds did not exist in the days of Jesus? Likely all dogs then were similar in terms of size, hair, color, behavior etc. and looked like what we now would call “a common street dog.” So does this mean that in only 2,000 years dogs have evolved into 200 new species? If so, this – like Darwin’s Finches – would be convincing evidence for evolution.

That, however, is not the case. Genetics has taught us how natural selection works. Every organism has unique DNA, grouped in genes on chromosomes. The genes are the units of genetic information that specify the “blueprint” for a particular characteristic of the organism. For instance in human beings, certain combinations of genes will control eye color, hair color, skin color, height and blood group as well as tendencies for high blood pressure and heart disease.

Through breeding and/or natural selection certain genetic characteristics are favored over others.  As these characteristics are controlled by genes, the organisms with these traits have their genes “set” to produce these characteristics. Therefore, offspring in subsequent generations are likely to have these same gene settings. This results in a dominance or even exclusivity of these favored characteristics.  So in a pure breed dog, the genetic information passed down from the parents is set to the desired characteristics of the breed. The genetic information that would produce the non-desired characteristics has disappeared through the selective breeding of the previous generations. Hence in terms of genetic information, pure breeds have less genetic diversity than “street dogs.”  Let me illustrate.  A pure breed Labrador will have only the genetic information that produces the characteristics of a Labrador . In a similar way, a pure breed German Sheppard has only the genetic information for the characteristics of a German Sheppard. A dog from the local dog pound, however, with a Labrador and a German Sheppard as his parents will have genetic information from both breeds. This animal might be less appealing to dog owners, but from a genetics standpoint it is actually “richer” in genetic information than the pure breed.

Thus natural selection or breeding does NOT lead to new species. It only emphasizes certain characteristics selected through controlled breeding (dogs) or the natural environment ( Darwin ’s Finches). It is always reversible. That is, if controlled breeding stops and the various breeds of dogs are allowed to mate together, in just a few generations all dogs once again will appear to be quite average.  

Darwin's Finches

Or in the case of Darwin ’s Finches, it has been observed on the Galapagos Islands that the beaks of the finches do not continue to grow. Actually the opposite happens – in rainy periods, the beaks grow smaller, more like the “traditional” finch beaks observed in Europe [1].

As nicely summarized by Dr. Elmer Noble[2]:

“Natural selection can act only on those biological properties that already exist; it cannot create properties in order to meet adaptational needs.”

How does natural selection and evolution relate? Are there historical breakthroughs in natural selection? Natural selection is widely observed in the world around us. Unfortunately it is often misused as evidence for evolutionary changes. Most evolutionary textbooks claim Darwin ’s Finches as well as peppered moths, bacteria resistant to antibiotics and insects resistant to insecticide as evidences for evolution. However these are mere examples of natural selection. By favoring certain – existing – characteristics the offspring of the organism has a better chance of survival. No new characteristics are formed, and over time, if the condition that favors these characteristics disappears, the suppressed characteristics begin to appear once more.

To make things even more confusing, these variations within a species are also dubbed micro-evolution, suggesting permanent changes in the species on a small scale. As explained, these changes might appear significant and permanent, but they are not. No new genetic information is added, actually the opposite happened – genetic information is lost.