The theory of evolution by natural selection was proposed in 1859 by Charles Darwin in his book On the Origin of Species. While science, by its very nature, is inductive (basing a theory on countless examples), Darwin created a new type of life science: evolutionary biology. Unlike other sciences which must be tested over and over again to verify one’s conclusion, Darwin introduced historicity into the sciences. The evolutionist’s primary concern is of constructing a historical narrative of what has already happened, as opposed to theorizing about what will happen in the future based on theories and laws. In his argument, Darwin claimed that two things must take place for evolution to occur.
- Branching evolution – all living species come from a common ancestor which over time underwent many changes
- Natural selection - (i.e. “survival of the fittest”) – the production of abundant variation in the population followed by the elimination of the inferior beings
The arguments in support of evolution are ever-changing. With each discovery of new information, scientists attempt to integrate the new facts into their prior theories to buttress, augment or possibly reject them entirely. The science of evolution is still young and new facts are constantly being found, but the basic argument for evolution and the steps necessary to allow for its progression have gone unchanged for almost a century. Any argument for evolution will always include at least five epochs:
- Big Bang event
- Period of stellar evolution
- Origin of life from complex organic molecules
- Development of natural diversity
- Origin of the human species
In the following, we will present the necessary pieces for an evolutionary theory. They will be listed along with a brief description of how they occurred and the arguments which favor their case. Even though an endless collection of additional shifts could also be inserted to construct this historical narrative of the universe, the following five epochs are the staple for any evolutionary theory.
1. Big Bang
There are three primary pieces of evidence that directly point to the historical conclusion that there was a Big Bang event:
A. The Expansion of the Universe
The expansion of the universe is evident from two sources. First, in the 1920’s, Edwin Hubble observed that the light emitted from farther away galaxies was redder than the light from those galaxies that were closer. In order to explain this phenomenon, he hypothesized that all the universe’s galaxies were moving away from each other; and all subsequent measures since then have achieved similar results. Second, according to Einstein’s Theory of General Relativity, not only should the universe be contracting or expanding at all times, but a static universe would be impossible.
These two points led scientists to theorize that the universe was once much smaller and that an explosion must have occurred at some earlier point that caused this observable expansion. Interestingly, they realized that as we look at earlier stages of the universe’s development, the density increases, the temperatures raise, and periods of exceptionally high energy are prevalent. George Gamow made two predictions based on this information, both of which were later discovered.
B. The Universal Background Radiation
The first of Gamow’s predictions was that a universal background radiation would be left over from such a large explosion as the Big Bang. In 1965, Arno Penzias and Robert Wilson discovered this radiation and won the Nobel Prize for their efforts.
C. The Distribution of the Elements
Gamow’s second prediction was that the elements should be found in the universe according to their complexity, with the simplest ones being found most often, while the most complex ones turn up the least. Accordingly, because hydrogen is the simplest of the elements, it should be the most widespread with helium following in a close second, etc. Luckily, the estimation of the quantity of the elements is not especially complex, and we have found that the universe very much parallels the predictions set forth by Gamow.
2. Period of Stellar Evolution
When one looks into a telescope, one is also seeing what stars and galaxies looked like billions of years ago. The farther one looks back, the more a hydrogen dominated universe will be found. Though, supernova explosions account for the diversity of elements present in our universe. It is known through direct observation that older, second generation stars are more dense and have heavier elements than younger, first generation stars. The theory of stellar nucleosynthesis can be used to predict much of what we see when we look into a telescope.
Stellar evolution presumes that three stages of development occurred in order to arrive at a galaxy in which could support life.
A. Basic Elements
After the Big Bang, the only elements were hydrogen, helium and traces of lithium, beryllium and boron.
B. Supernova Explosion
When stars use up their nuclear fuel, they die. There are two types of star death: massive stars die violently in a supernova explosion, while smaller stars die more peacefully by shedding its outer layers and forming planetary nebulae. Freshly synthesized heavy elements are injected into space where they mingle with the surrounding interstellar gas and dust.
C. Second Generation Galaxy
Because our galaxy has heavier elements, it must be the product of a supernova explosion; it is a second generation galaxy. In other words, there was a supernova explosion before our sun came into existence. The heavier elements of our galaxy were the product of nuclear burning inside the earlier star. The burning of hydrogen produces helium, while the burning of helium produces carbon and oxygen. All the elements on earth today were once part of stars.
3. Origin of Life
Ever since Charles Darwin privately suggested that life could have started “in some warm little pond, with all sorts of ammonia and phosphoric salts, light, heat, electricity, etc. present,” no one has really been able to get much closer to definitively describing the actual process that produced the origins of life. While it is known that the earth formed 4.555 billion years ago, and the first fossil microorganisms discovered are 3.5 billion years old, there is no scholarly consensus on the bridge that links the two periods. Even though scientists are aware of the necessary components to construct life, and currently there are six viable theories on the table, the phenomena of life cannot be reproduced in the laboratory. Until now, none of the current theories have been verified, yet neither have they been rejected. Though, one matter that has gained universal acceptance is that of common ancestry – all life on earth comes from one original organism. It is virtually impossible that the similarity in all life is accidental. Some of these similarities include:
One Source of all Life
A. Carbon – All living things consist of carbon rich material.
B. Amino Acids – The proteins found in organisms are fashioned from one set of twenty amino acids.
C. RNA and DNA – All organisms carry their genetic information in nucleic acids, in RNA and DNA.
D. Genetic Code – They all use essentially the same code (sequence of nucleotides); they instruct the cell how to act. Because the structure of a gene is generally preserved over millions of years, it has been discovered that many of the basic genes for higher organisms can be traced to homologous genes in bacteria – their ancestor.
E. Common Ancestry – Our last common ancestor stored genetic information in nucleic acids that specified the composition of all needed proteins.
F. Molecular Biology – the more closely that two organisms are on the evolutionary tree, the more similar their molecular makeup (and their genes) will be. Even when the morphological evidence is ambiguous, one can fall on the molecular evidence to define relationships.
Unnecessary Characteristics that Demonstrate Common Ancestry
G. Embryonic similarities All early mammal embryos resemble each other. As the embryo gets older, it becomes more highly specialized. Though it would be wrong to say all embryos are identical as some early embryologist theorized, neither can their overwhelming similarities be disregarded.
H. Recapitulation – Certain structures appear and then disappear in the development of the embryo; this is called recapitulation. For example, embryos of birds and mammals develop gill slits and then they disappear.
I. Pseudogenes – they are unnecessary and functionless genetic material that is past down from generation to generation; they do not influences species’ biological structure. Identical Pseudogenes have been found in varying species.
J. Vestigial Organs – Like pseudogenes, vestigial structures – some not fully functional and some not functional at all – which are remnants of functional structures in their ancestors.
K. Homologous Bone Elements – certain characteristics of two species are nearly identical, except for evolution’s adaptive modification. For example, humans, cats, whales and bats all have nearly identical bones in their respective hands including five fingers.
Necessities for Life
Once we admit that all life had a common ancestor, the next step is to identify that living organism and how it evolved from a non-living predecessor. The problem is that we are searching for something that would not quite be called alive, though possesses many of the character traits that we would only associate with the living. There are entities around today that might help us to understand this point; they also blur the line between the living and the non-living in our world. For example, seeds and viruses, which both could remain dormant for centuries (lacking all the characteristics of a living entity), then spring to life given the right impetus. So should we define seeds and viruses as living or not? Similarly, we are looking for something which also blurs this line, but it must also have genetic information (heritable instructions for functioning and reproducing) that allows for some random variation in the heritable characteristics of its children so that new species could arrive. One can imagine how big of an obstacle this really is. .
In the following, we will outline the primary theories scientists are toying with today. Though, one should keeping mind that all these theories are still in their early stages, and it may be many years until one is established as the true mechanism for evolution (if any of them ever are). The name of all the articles containing the six prevalent theories, and where they can be found, are found in the additional readings.
RNA weakens the boundaries that distinguish between life and inanimateness. RNA (ribonucleic acid) can reproduce itself, and not simply assemble and disassemble like other molecules. Furthermore, nucleic acids that make up RNA and DNA can be found in places that have early earth conditions. Some further proofs for this theory include:
1. The main reaction in the synthesis of proteins is done by a type of RNA
2. The first enzyme that bonded amino acids to transference could have been RNA
3. There exists a rudimentary genetic code in certain retro viruses.
B. Hot World Hypothesis
Submarine volcanoes contain rich ecosystems that might have sprung the first living beings. The bacteria present there could withstand intense heat and other harsh conditions.
C. Clay Hypothesis
The crystals in clay possess the ability of replicating themselves, growing and evolving through natural selection. At a certain point in time, this clay system could have come to the point where it included in its structure organic molecules, specifically RNAs that, through the passage of time, eventually gained control of the process.
They provided the necessary elements to produce life. Asteroids with real organic substances have been discovered including graphite, 74 amino acids and almost 250 different hydrocarbons, and five nitrogenized bases of DNA (adenine, guanine, cytosine, thymine and uracil).
Origin of Proteins
But where did these proteins come from? We have already said that stellar evolution could only account for the elements present in our world. Nonetheless, one interesting possibility was discovered in 1953. In an attempt to emulate the primitive atmosphere, the chemist Stanley Miller poured a mixture of ammonia, hydrogen and water vapor, what has been called ‘primitive soup,’ into a wide container. Once the container was sealed, he caused an electric storm in its interior. After two weeks of this, Miller analyzed the results and found that that at least two amino acids had been formed: alanine and glicine. Conducting similar experiments, 14 of the 20 natural amino acids appeared.
1. It is not known how then DNA stole the leading role from RNA.
2. It is not known how organic matter came together to originate the first cell.
3. Nowadays nucleic acids are synthesized only with the help of proteins, and proteins are synthesized only if their corresponding nucleotide sequence is present. It is extremely improbable that proteins and nucleic acids, both of which are structurally complex, arose spontaneously in the same place at the same time. Yet it also seems impossible to have one without the other. And so, at first glance, one might have to conclude that life could never, in fact, have originated by chemical means.
4. Development of Natural Diversity
Before proceeding to the fourth epoch of evolution, we will digress to introduce Darwin’s contribution to science, namely, evolutionary biology and hopefully explain why Darwinism is now almost unanimously accepted by knowledgeable evolutionists. Evolution is one of the most misunderstood theories in Jewish circles. This point is highlighted when one takes into account how many Jewish books include the design arguments such as “watches don’t randomly appear in deserts without a maker” or “the complexity of an orange itself disproves evolution.” Is one to assume that evolutionists and biologists are all ignorant of this point? Are we to think that they do not know how complex the eye is? These arguments, while well intentioned, fail to respond to the primary claims of Darwinian evolution.
A. Non-Constancy of species (i.e. evolution)
Evolution is the change in the inherited traits of a population from generation to generation. Mutations, and other random changes in these genes, can produce new or altered traits, resulting in heritable differences (genetic variatio) between organisms. Evolution occurs when these heritable differences become more common or rare in a population. In of itself, evolution is a passive processed that can only be discerned after the fact.
B. Branching evolution
This is the theory that one species may give rise to a multiple of others. Branching evolution is accomplished through speciation. There are many types of speciation, but in general, it means that one population somehow is divided into two and evolve independently. Eventually, they cannot breed any more with the one another; they are called reproductively isolation. Taken to it logical conclusion, the theory of branching evolution leads to the assertion that all living things on earth come from one common ancestor. This is referred to as the theory of common descent.
C. Gradual Evolution
Even though Darwin thought that evolution was a gradual process, all evolutionists today now accept that it happens in quick epochs.
D. The Multiplication of species
A species is a group of organisms that can reproduce with one another. When a species is separated into populations that are prevented from interbreeding, then mutations and other mechanisms result in the accumulation of differences which, in turn, cause the emergence of new species. At some point, every species broke away from a sister species when the children of one could no longer mate with their distant relatives.
E. Natural Selection
Natural selection is a process that causes heritable traits that are helpful for survival and reproduction to become more common, and harmful traits to become rarer. This occurs because organisms with advantageous traits pass on more copies of the traits to the next generation. Over many generations, adaptations occur through a combination of successive, small, random changes in traits, and the natural selection of the variants best-suited for their environment.
It locates the mechanism of evolutionary change in a “struggle” among organisms for reproductive success, leading to improved fit of populations to changing environments. It is a principle of local adaptation, not of general advance or progress.
a. Survival of the Fittest
Unlike the forces of physics which are determined based on the initial equation, natural selections’ mechanism is simply the elimination of inferior individuals or to say it crudely “survival of the fittest.” The discovery of natural selection made unnecessary the invocation teleological premises for nothing is predetermined for randomness is the force which drives reproductive isolation. Once a diverse population appears, elimination of the inferior population necessarily follows.
b. Reproductive Isolation
We have already pointed out that all life forms come from one common ancestry, and therefore must also share a common genetic code. There are many facts that point to a common genetic code among the world’s living beings. Natural selection provides us with another proof of life’s common ancestry. When species no longer have the ability to reproduce with one another, they are called “reproductively isolated.” Many times a geographical barrier will arise that bifurcates a species into two dissimilar habitats, and given enough time for adaptation through mutation and selection, this geographical isolation will foment the primal species to bifurcate into two distinct species unable to reproduce with one another.
5. Origin of the Human Species
There is a seemingly endless array of anatomical, fossil and molecular evidence that supports the theory that mankind evolved from African primates, and more specifically from apes. While paleoanthrologist assume that chimpanzees are mankind’s closest relative in the animal kingdom, the historical narrative that describes mankind’s descent from apes is still tentative, and subject to change with every new discovery of a pertinent fossil.
In the following, we will proffer a truncated viewpoint of the sequence of events that started roughly eight million years ago when the descendant of the human race broke off from apes. The most important fossils found are:
- Though there is no fossil evidence for the branching between the chimpanzee and mankind. Australopithecus ramidus lives about 4.5 million years ago.
- Lucy, dated around 3.5 million years ago, weighed about seventy pounds as an adult, walked erect and had a smaller brain than we do today.
- Homo habilis lived two million years ago. He had a larger brain and used tools.
- Homo erectus, whose fossils were found in many places, used fire and lived until about five hundred thousand years ago.
- Homo sapiens appeared about two hundred thousand years ago.
Besides the fossil records, other evidence exists that could trace human ancestry to primates.
- Considered the strongest evidence for evolution, human DNA is ninety-eight percent identical to chimpanzees, our closest relatives. Even though man’s lineage separated from chimpanzees six million years ago, the especially complex molecules of the hemoglobins of the two are virtually identical.
- Our many vestigial organs can be traced to necessities at earlier stages of our evolution.
- Tradition - Mankind is unique in that man is the only animal to bestow learned cultural information on the next generation.
- Awareness – Mankind is the only animal who is able to talk about the future and the
past; other animals lack the mental capabilities to adopt syntax.
Concepts the theory of evolution has shown unnecessary:
- Typology (essentialism) – There is no longer any reason to uphold any classifications within populations; variation is accidental. Because all beings share a common ancestry, the differentiation between groups of living organisms is not noteworthy.
- Teleology – Natural selection opposes determinism, and nothing is predetermined in the physical world; it makes unnecessary the invocation of any final causes.
- Supernaturalism – Evolutionary theory does not invoke God or any other supernatural force to explain the diversity and detail in the world.
To be remembered:
A. God – The theory of evolution does not reject God or theistic belief. There is no problem with saying that the Big Bang was directly caused by God or that God cares about the world or the human race.
B. Science – Evolution is fueled by the notion of “Occum’s razor:” the simplest explanation is the right explanation. Evolution explains the physical world without invoking any supernatural elements, but it does not negate them. Technically, the evolutionary theory does not supply any opinion about God, the human soul, salvation, theology or metaphysics; it cannot. The second it does, the impenetrable chasm that separates the two is broken, and the exercise is no longer science, but theology.
C. Miracles – Though the theory of evolution rejects miracles as an explanation for the appearance of the present world, it does not reject the possibility of miracles.
D. Mankind – The rejection of typology (essentialism) also means the rejection of mankind’s unique status among the organisms of the world. Nonetheless, even though the theory of common descent of Man deprives mankind of a special typological status, it does not divest him of his Divine inheritance: his soul. Evolution has nothing to add.
E. Scientists – Not everyone who believes in the theory of evolution is an atheist.