Evolution is a scientific theory, in the scientific sense of an explanation supported by objective evidence, that explains how life began and how it developed into the complex forms we see today. It is not completely understood but there is so much scientific evidence supporting it that it is accepted as true by an overwhelming majority of scientists. Despite this mass of evidence and scientific support, there is a religiously motivated minority who contend that evolution is untrue and never happened. Instead, they contend that god created kinds of plants and animals individually, i.e. by a process of special creation, and built into them the capability of variation within strict limits, such as we see with yellow or orange flowers on the same kind of plant, or different breeds of dogs.
This point is often overlooked by evolutionists, who presume that special creation means god created every single animal individually. There may be some who do believe that, but most will accept the observable capability of animals to change their characteristics over generations by selective breeding, whether natural or artificial. For this group of creationists, the term “kind” equates more with the scientific classification of genus rather than species, although it is unwise to presume that they are exactly the same. The deciding factor is based on what god is recorded to have said in Genesis, that all life will reproduce “after his kind”. If two animals can breed, even by artificial insemination, and produce live offspring then their view is that the animals are of the same biblical kind. If the resulting offspring is infertile then it is believed that the limits set by god have been reached. In a case involving three animals, where two can breed and produce live offspring, and one of those two cannot breed with the third but the other can, they are all considered to be of the same kind, but the offspring of the two not able to breed would exceed the limits set by god for the kind.
Understanding this is relevant to discussions on evolution since one of the commonest examples given by evolutionists is to refer to the observation that the population of a particular moth changed its colouration over a period of time because environmental pollution and predation resulted in the selective removal of light coloured individuals, leaving greater numbers of dark coloured moths to breed. This kind of observation is rejected as an example of evolution by creationists and is seen as an expression of the god given ability of kinds to vary. They will point out that if the environment reverts to what it was before the change, then the numbers of light coloured moths will rebound. Evolution, they say, requires production of new kinds of animals, not just variations in appearance of existing animals. To creationists it also explains the existence of domestic cats and dogs, initially produced by hybridising different types of animals of the same kind, then stabilising the hybrid and producing new varieties by selective breeding. The same argument is used for plants. They are not seen as examples of evolution.
The problem in dealing with these kinds of arguments is that evolutionary change is so slow. In most cases it takes hundreds of thousands of years for significant enough changes to occur so that a new species develops to such an extent that it can no longer interbreed with the original species or a descendent which developed in a different direction, although the Cichlid fish found in some African lakes appear to have formed many new species in less than 25,000 years. Almost all animals alive today are undergoing evolutionary change, but those changes are so slow that the effects can scarcely be detected.
Modern DNA techniques are a solution to this problem and can show very minor changes to living organisms. Comparing old DNA with modern DNA can trace development of a species, and this can be used to show migration patterns around the globe, including human migration.
The bible says that Noah, the man who was told by god to build a big boat, an ark, so that all the kinds of animals could be preserved along with humans during a world wide flood caused by the “waters above the firmament” coming down. Noah had three sons, Shem, Ham and Japheth, who became the originators of all people on the post flood earth. If this were true, DNA studies would show that human migration originated somewhere in the middle east, which is where Noah and his sons are supposed to have originated and where the ark was supposed to have grounded, and that there were only three major ancient divisions among the human genome, all originating from that same area. This is not what DNA shows.
DNA tends to change (mutate) at a relatively standard rate, and the longer in the past a change occurred in a group, the more people will have it reflected in their DNA as it would be passed on to their offspring. DNA analysis of the current world population indicates that the ancestors of all modern humans originated in Africa and migrated through what is now Palestine, some branching into various parts of Europe, some branching into Asia. These studies also indicate more than one migration, with one of the oldest being a migration out of Africa, through Asia and on to Australia. These studies are often based on the DNA found in a human cell constituent called a mitochondrion. This DNA is passed on by a female to all her children as a constituent of her ovum or egg cell, allowing female ancestry to be followed by the changes that occur in this DNA over time. Similarly, male ancestry can be followed by changes to the Y chromosome. Together, they give a fairly clear picture of where we come from.
The map to the left shows the routes taken by humanity’s ancestors as determined by mutations in our DNA. This is from the National Geographic Genographic project, which is tracing the migration patterns of ancestral humans. The oldest are clustered in Africa, not the middle east, and there are obviously more than three. The area in Africa marked by a red dot is where the DNA with the least mutations was determined to be. In other words, “Adam” and “Eve” lived there. Of course, Adam and Eve, in this context, are not necessarily specific individuals but a cluster of closely related males and a cluster of closely related females, and the clusters may not have lived at the same time.
Quite obviously, the bible claim that all living humans came from the three sons of Noah somewhere in the middle east is wrong.
A second point is the time line involved. Once humans left Africa, these migrations happened over a period of 50,000 years or so. The time periods involved can be determined by the number of mutations to the DNA, since the mutation rate is fairly constant. It is estimated, for instance, that the migration into Australia by the ancestors of modern Aborigines happened about 50,000 years ago (50 KYA), well beyond the 7,000 years of the seventh creative day. Much the same period of time appears to be involved with the migration into Europe, although it happened later than the migration into Australia. The major point with this is that another species of human was already living in Europe when Homo sapiens arrived. This was Homo neanderthalensis, and they had been in Europe for tens of thousands of years by the time our ancestors arrived. In fact, some of our modern European DNA is Neanderthal in origin, indicating that the two species of human hybridised and Europeans are the stabilised offspring. A similar situation appears to have taken place in Asia with a hominid called the Denisovan man. The evolutionary point, however, is that humans of one species or another have been living in Europe, Africa and Asia for many times longer than the 49,000 years that creationists espouse. That has been scientifically proven.
|I find it quite ironic that racists who say black people are inferior to white people are actually mongrels or hybrids, whereas black Africans are pure Homo sapiens as far as anyone can tell.|
Evolution is often criticised on the basis that some organs could not have developed by chance, since they will only function if fully developed, the eye being the usual example. This is just not so. The eye almost certainly developed from sun sensitive cells on the outer membrane (skin) of a primitive animal. Even today humans have cells like this as do numerous other animals. That is why our skin darkens in sunlight with the production of melanin, or some animals, such as chameleons, change their colour patterning depending on their surroundings. A mutation which increased the sensitivity of cells which reacted to light would be useful to make a primitive animal aware it was in sunlight. Another mutation could increase the number of the light sensitive cells involved, another could increase the area covered by the cells by developing a depression in the membrane that was lined by them, another could separate the outer membrane layer from the depressed cells, another could form a deeper depression and increase the number of light sensitive cells, another could thicken the central area of the separated membrane and concentrate more sunlight on the cells, another could cause the thickened area to separate from the membrane, another could change the shape and cause the light entering through the transparent membrane to focus an image on the cells in the depression. At every step during this process, the cells would be providing valuable information to the animal about its relationship to sunlight. Now, whether this was the actual developmental route is not the point The point is that it does illustrate that it is quite possible for an eye to develop and for all the intermediate forms to be useful before it is a fully functional eye.
Among living animals, DNA studies show a clear and very close genetic relationship between common chimpanzees and bonobos on the one hand and humans on the other. We share 98% of our DNA with these chimpanzee species, and our ancestors separated from their ancestors about 5-6 million years ago. Australopithecus is an animal that had both chimpanzee and human characteristics and lived about 3.5 million years ago, as do some other hominid fossils from Africa in the same general time period. If a “missing link” is demanded then those species are it, although there are likely many such links in a long progression leading to modern humans.
One aspect of evolution is the subject of a social taboo, but it involves a question that needs answering scientifically since it has relevance to both evolutionary science and religious dogma, although the latter is probably the basis for it being a taboo. The question is whether chimpanzees and humans can interbreed. If this were possible, even if only by artificial insemination or in vitro fertilisation, it would mean they were genetically close and might be candidates for being two species in the same genus. Certainly, they would have to be considered to be of the same bible kind, even if the hybrid offspring were to be sterile in the same way that a horse and a donkey are said to be of the same kind when producing a sterile mule. If they were able to interbreed they would be reproducing after their kind, according to the bible, and that would mean chimpanzees were of the same kind as humans. They would have to be considered sons of Adam by creationist Christians, since he was the first of the human kind, and subject to the ransom sacrifice of Jesus the same as every other descendant of Adam. The choice would be to accept chimpanzees as human and subject to what Christians say is god's plan for mankind, or to deny chimpanzees’ humanity and explain how two different kinds can interbreed in contradiction to what god stated as a restriction in Genesis, that animals would reproduce after their kind. To a very similar extent this would apply to bonobos, gorillas and orangutans as well, all of whom have DNA differing from humans by only a small degree.
This is all speculation, of course, since there is no evidence that cross breading has actually taken place. Even if it had, it would almost certainly be denied since no reputable biologist would want to admit to such an unethical act. Asking and answering such questions, however, does indicate a possible approach to resolving difficulties of this nature. It also highlights some of the difficult questions that would arise should special creation be taught as an alternative to scientific evolution, questions that would require religious answers and on which different religions might have different opinions. Religious answers have no place in science courses.
When discussing the story of Noah’s ark it is usually stated that animals were taken into the ark by twos, a male and a female, and that all existing animals alive now are the descendants of those animals. That is not what the account actually says. According to the book of Genesis, chapter 7, unclean animals were taken in by twos, a male and a female, the clean animals were taken in by sevens, although there are some translations which render this seven pairs, e.g. fourteen animals, because the original Hebrew refers to taking them by seven twice, then refers to male and female, the inference being seven of each.
There are two points to be made about this. The first is the number of animals Noah had to take into the ark, along with food for them and possibly water, because the water the ark was floating on would certainly have been contaminated for some of the flood period by rotting corpses of man and animals.
One also has to consider whether the ark was big enough to store all the fodder for all the animals for at least a year, perhaps longer, since after the water receded there would have to be enough time for the vegetation the animals ate to grow. Also, bear in mind that a significant portion of the ark would have had to be used for stables and living space. In addition, a significant number of the animals taken into the ark were carnivores, that is, they ate meat from other animals. Cats, dogs, hyenas, snakes and numerous others would have required other animals as food. Were these in addition to the two of each kind taken into the ark to preserve them, or did they come from those intended to found new animal lineages? If they were supernumerary to god’s instructions, was Noah disobeying god, since there is no mention of taking in some animals so they could be used as food for others? If not supernumerary, how could a single animal produce a new generation after its mate was killed off to feed a snake, for instance? According to the account the flood covered the earth for a year. If meat were taken in already slaughtered, how was it kept fresh for that long. Unpreserved meat rots, so what method of preservation was used? Perhaps we are to believe that carnivorous animals ate grass and other plants before the flood. If so, where is the evidence?
One also has to consider the salt level in the water. There is a natural propensity to presume that the flood waters were fresh, like rain is today, but we have to take into account that when this water drained off the earth it left the seas, which are extremely salty. Was the flood water actually salt water? If the answer is yes, then why didn’t the fresh water fish die off during the flood? Anyone who keeps fish in an aquarium is quite aware that fresh water fish do not tolerate salt very well and usually die very quickly in water as salty as seawater is, although there are a few exceptions. Noah would also have been required to have a very large supply of potable drinking water available for the animals and his family. Would the ark have been big enough to store enough for a year or more? Why was the subject of potable water not mentioned in the instructions god is said to have given him?
If the answer is that the inundation was fresh water, then how did salt water fish cope with the sudden decrease in salinity, which would have much the same effect on them as increased salinity would have on fresh water fish? If the flood water had such a low salinity that it could be drunk as potable, fresh water, why are the seas now so saline? Why is their salt content so high? Were the preflood seas even saltier than the present seas so that the fresh water from the inundation diluted it to the level we now have? If so, what lived in this excessively saline water. The closest we would have to it today is the Dead Sea but, because the dead sea is extremely salty, no fish live in it, only simple life forms. How did the thousands of species of fish in the seas respond so rapidly to such a change in salinity, since they can no more live in fresh or low salinity water than fresh water fish can live in the saline sea? Finally, where did all the water covering the earth to submerge the highest mountains go? If the answer is that the bible says it drained off, then to where?
The instructions to Noah were that seven pairs of clean animals and birds, plus one pair of unclean animals were to be taken into the ark. The numbers of animals would have been quite substantial even if only two of each were taken on board. With fourteen of some animals it would have been quite burdensome. Although many animals are quite small, there are also some which are quite large: cattle, sheep, goats, deer and so on. Among the unclean animals there are also those which are quite sizable: elephants, horses and camels, for instance. I don’t know how many kinds of animals there were, but it must have been significant, even if many different species were placed into a single kind. That raises another question, of course, when a kind has more than one species, did the male and female have to be of the same species or were they from different species within the same biblical kind?
The concept of animals being clean or unclean is an integral part of the ancient Jewish laws, still followed today. The animals considered as unclean are given in Leviticus, chapters 5 onwards, along with practices which made people unclean. The point is that the definition of clean and unclean animals is given in Leviticus after the ancient Israelites left Egypt in the exodus, yet Noah segregates animals as clean and unclean several hundred years prior to that while deciding how many of each to take onto the ark. How can a decision be made about an animal being clean or unclean hundreds of years before the concept of clean and unclean animals came about? The logical conclusion is surely that the story of Noah was written after the establishment of Jewish dietary rules, rather than being a history preceding it, and is therefore unreliable as a basis for explaining the origins of mankind.
Other questions have to be asked about the biological aspects of animal kinds and the great diversity that can be found within kinds. Horses are one of the unclean animals since they do not chew the cud and do not have cloven hoofs. The same applies, of course, to all animals in the horse kind: horses, asses, zebras and hybrids between them, such as mules, hinnies and zorses. There is one extant species of horse still living in the wild, although we are more familiar with the many breeds of its domesticated descendants. There are three extant species of zebras, although others have gone extinct, and three species of asses. The ability for these animals to hybridise shows they are of the same kind, according to the bible, because they would not be able to reproduce with each other if they were not.
The significance of these three types of animals being in the same biblical kind is that, according to the story in Genesis, they all came from two animals taken into the ark, a male and a female of the horse kind, although it is not specified what particular type of horsy animal Noah chose. In spite of that, we are to believe that within a period of a thousand years or so, all seven extant species of the horse kind, and a few types that have gone extinct within memory, developed from two individual animals and formed discrete, isolated breeding populations with characteristics so radically different and distinct from each other that they are considered by both ancient and modern people to be different types of animals, different species. At the same time, one of these, the horse, was deliberately and intensively bred to develop varieties with individual and distinct characteristics but has never formed more than one species.
This process, of course, must have been emulated by every single one of the animals and birds contained in the ark. All the species of finches came from 14 birds, all the eagles came from 14 birds, all the pigeons came from 14 doves, all the birds of paradise came from 14 birds and so on for every different kind of bird. In addition, all peccaries, wild boar and domestic pigs came from two animals. All the lions, tigers, leopards, cougars, cheetahs, wild cats and house cats all came from two animals. Plus, all this differentiation into different animal species happened within a thousand years or so after the flood, since all these animals were known at the time the bible was written, house cats being mummified in ancient Egypt, for instance. Lets not get started on dogs, rats, mice, rabbits, voles, squirrels, kangaroos, possums, and dozens more, all of whom must have had the same differentiating process take place within that same time period. The complexity of species generation within the thousand years immediately following the flood must have been absolutely astounding, yet it all happened without producing a single fossil, without producing a single shred of evidence that it took place. We have preserved human remains from that period but no animal forms other than those already completely differentiated into the new species.
Having said all this, it is quite clear that belief in creation and denial of evolution is not based on rational deduction, scientific or otherwise. It is based on faith, and you will recall that this was defined by the Apostle Paul in his letter to the Hebrews (chapter 11, verse 1) as, “Faith is the substance of things hoped for, the evidence of things not seen.” This makes it clear that faith is not founded on proven science, but is a firm belief that is adhered to even when the scientific evidence shows it to be wrong. This is the attitude of evolution deniers. No amount of proof will change their minds because they have faith that the bible is true and science is wrong. Disputing with someone who believes like this is therefore pointless, although the subject is sometimes initiated by the religious as a means of starting a conversation with the hope of evangelising and gaining a convert.
The point is that if the questions raised by rational discussion of the bible accounts of creation and Noah’s ark cannot be answered with equally rational answers from its proponents which satisfy the criteria for a scientific debate, then the whole subject has no place in a science class.
There are other religiously motivated people who accept that evolution happened, but believe the process was directed by god in some way and that the story of Noah is allegorical rather than actual. Since this approach merely explains evolution as being directed by god and sees the creative days and process as a metaphor, it is not a denial of proven scientific evidence, merely a religious choice, and such people rarely object to evolution being taught in science classes.
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