Fossils showing stability over time...............
Many fossils, like this jellyfish fossil, actually show stability of some species over time rather than change and there is a lack of intermediates. Species that are the same as their fossil ancestors are called "Living fossils".
On this page the ability for organisms to adapt and mutate are briefly explored. It is recognized that organisms adapt to a limited extent to their environment, and that mutations may play a role in the characteristics of organisms. However, such changes do not produce new information at a genetic level.
Despite the incredible variety of nature, there are similarities between groups of plants, insects, fish,amphibians, reptiles,birds, mammals etc. However, do such similarities point towards a common ancestor or a common designer?
The main method for generation of diversity (e.g. such as the diversity in dogs and humans) in eukaryotic organisms occurs during the process know as meiosis(see picture below)when there can be rearrangement (crossover) of genetic material between chromosomes as the haploid sex cells (e.g. in animals sperm and eggs) are formed from diploid cells (Swift, D., 2002).
In 1911 the American geneticist Thomas Hunt Morgan (1866-1945) observed cross-over in Fruit flies and the process was called Meiosis.
In meiosis, the diploid cell's genome, which is composed of ordered structures of coiled DNA called chromosomes, is replicated once and separated twice, producing four haploid cells each containing half of the original cell's chromosomes. These resultant haploid cells will fertilize with other haploid cells of the opposite gender to form a diploid cell again. The cyclical process of separation by meiosis and genetic recombination through fertilization is called the life cycle. The result is that the offspring produced during germination after meiosis will have a slightly different blueprint which has instructions for the cells to work, contained in the DNA.
However, meiosis and sexual reproduction combined do not have the capacity to produce new information, the diversification is due to genes that are already there being swapped / mixed and some genes may become dominant whereas others become recessive etc.
Selection can then be involved in choosing a successful organism within a specific environment, however, if the gene rearrangements are solely due to meiosis and combining of genes from a male and a female, then the selection will be only selecting a sub-set of the genetic information that was there in one of the parents.
Mutation can cause change to the genetic material, but the overwhelming evidence suggests that mutation leads to corruption of original information, not enhanced or new information. See Mutationfor more information.
Thus, whilst these processes do lead to biological variation limited by the ability of organisms to change in response to environmental conditions (micro-evolution), they do not lead to the full range of species on the Earth (macro-evolution), as we will explore more below.
"Evolution has gone wrong by exaggerating the ability of a creature to make tall, short, green, red copies of itself into beliefs that chemicals turn into cells" (Mackay, 2000).
However, the video on You Tube below, suggests it is not an issue of the degree of change (e.g. macro or micro-evolution), but the direction of change (downhill with less information or up hill with more information). Some changes may give rise to new variants within a type, but if there is no increase in complexity, this is diversification not evolution. See audio-visual page for more videos in this series.
What many people confuse with evolution is the genetic variability of plants and animals, the limited ability of organisms to adapt to their environment and the natural selection of favourable characteristics for a given environment within pre-existing species by selection of some genes in favour of others. This limited variation is termed micro-evolution, for example, see below the selection of a certain type of peppered moth under certain conditions.
The following has been said of macro-evolution. "A well-informed minority, including such outstanding authorities as the geneticist Goldschmidt, the palaeontologist Schinderwolf, and the zoologists Jeannel, Cuenot, and Cannon, maintained until the 1950's that neither evolution within species nor geographical speciation could explain the phenomena of macro-evolution.... These authors contended that the origin on new "types" could not be explained by the known facts of genetics and systematics". (Mayr, 1970).
What is a species? When considering whether living organisms change from one species to another over time, it is well to first consider what a species is? Some definitions of species taken from the web (click here to see original) are:-
1. A group of organisms that have a unique set of characteristics (like body shape and behaviour) that distinguishes them from other organisms. If they reproduce, individuals within the same species can produce fertile offspring.
2. The basic unit of biological classification. Scientists refer to species using both their genus and species name. The house cat, for example, is called Felis catus.
3. The lowest principal unit of biological classification formally recognized as a group of organisms distinct from other groups. In sexually producing organisms, "species" is more narrowly characterized as a group of organisms that in natural conditions freely interbreed with members of the same group but not with members of other groups.
From the above we can see the humans, mice, dogs, cats, sweet peas, carrots etc fulfill the criteria of being a species as they can inter-breed and have similar characteristics.
Birth of a new species? In a report in BBC News Online, 9 Jun 2004 published in the Proceedings of the National Academy of Sciences, Scientists at the University of Arizona have been studying breeding patterns in fruit flies and believe they are witnessing the birth of a new species.
In the Arizona desert there are two groups of fruit flies, named "Drosophila mojavensis" and "Drosophila arizonae," which don't interbreed even thoughtheir geographical ranges overlap. Biologists were able to get them to cross-breed in the laboratory, but found male offspring from a cross between D. arizonae females and D. mojavensis males were sterile. The scientists who carried out the breeding experiments claim that the limited capacity for interbreeding is a sign that the two groups of flies are about to become completely different species. They also claim genetic change involved must be recent, because the male hybrid sterility depends on the mother's genes. BBC news science editor Dr David Whitehouse commented: "In fruit flies there are several examples of mutant genes that prevent different species from breeding but scientists do not know if they are the cause or the consequence of speciation. (Creation Research Evidence News Update No.14, 26th August, AD2004).
However, all that is happening here is a large and varied group of flies is splitting into two smaller less varied groups of flies, because of a mutant gene. This is degeneration, not evolution. It's a good reminder that speciation is not evolution. (Creation Research Evidence News Update No.14, 26th August, AD2004).
Mutation. Is there any evidence that mutation leads to new more complex organisms? Certainly there is plenty of evidence that mutation leads to disease and loss of function, and this is explored in this section. Please scroll down or click for specific topic.
Mutations include deletions (loss of DNA bases), insertions (gain of DNA bases), and missense or nonsense (substitution of a DNA base). Such mistakes are rare (Alderson and Rowland, 1995) and cells have mechanisms to correct errors in DNA replication. In most cases mutations are to the detriment (Alderson and Rowland, 1995) of the organism (see Bacteria below). One only has to consider the harmful affects of radiation following nuclear fallout on subsequent babies born to women exposed to the radiation, to realise that mutation is normally harmful, not beneficial (radiation damages DNA).
If the mutations affect germ cells (female ova and male spermatozoa), they will be passed to all the cells of the offspring, and affect future generations. Such mutations are called "germline mutations," and are the cause of inherited diseases.
Mutations also occur in other populations of body cells and will accumulate throughout a lifetime without being passed to the offspring. These are called "somatic mutations," and are important in the genesis of cancers and other degenerative disease processes.
Mutation and human disease. Literally thousands of human diseases associated with genetic mutations have been catalogued in recent years, with more being described continually (some can be seen at this site). A recent reference book of medical genetics listed some 4,500 different genetic diseases. Some of the inherited syndromes characterized clinically in the days before molecular genetic analysis (such as Marfan's syndrome) are now being shown to be heterogeneous; that is, associated with many different mutations. This review will only scratch the surface of the many recent discoveries. Still, the examples cited will illustrate a compelling general principle which extends throughout this expanding field.
In human beings, known mutations which are not silent (e.g. silent mutants are those which do not change the amino acid and therefore the protein) are generally harmful. One case - that of sickle cell anaemia - provides some protection against malaria. However, apart from that one asset, the condition is not recommended. Sickle cell anaemia represents an assault on the way blood cells work. There is one beneficial effect, but this is counteracted by harm done to the human physiology system. A vivid demonstration of this claim has come from observations of humans (with sickle cell anaemia) operating under extreme conditions, where some have been known to collapse and die.
Mutation that gives rise to sickle cell anaemia
On the left is the DNA and on the right is the protein that the DNA codes for. Change (mutation) of one DNA nucleotide is sufficient to alter the protein and to produce a life threatening disease.
To consider in detail specific mutations that can be involved in heart disease, please see another web-site.
In view of the overwhelming evidence that mutations lead to damage and loss of function, it is difficult to envisage that mutations can be factors involved in creating more complex, fully functioning organisms.
Christians who would argue that a loving God would use mutations to bring about new species, must deal with the issue of the devastating effects mutations can have on the lives of individuals.
Mutations and experimental evidence. Experimental evidence backs up the observations that mutations are generally harmful and do not produce anything new. Fruit flies have been exposed to radiation (which produces mutations in the DNA at a much higher rate than would normally occur) to try and establish if this led to the fruit flies developing new advantageous characteristics (Dobzhansky T. and Pavlovsky O., 1971). This produced many varieties of flies, flies with small wings, large wings, no wings, extra wings, etc. but all new products were essentially corruptions of the original, with no essentially new features.
Michael Delsol, professor of biology at the University of Lyon said of this experiment:- "If mutation were a variation of value to the species, then the evolution of the Drosophila (fruit fly) should have proceeded with extreme rapidity. Yet the facts entirely contradict the validity of this theoretical deduction, for we have seen that the Drosophila type has been known since the beginning of the Tertiary period, that is for about 50 million years and it has not been modified in any way during that time". (Delsol, Encyclopedia of the life sciences).
In a similar way, Professor Pierre-Paul Grasse, past president of the French Academy of sciences has said:- "No matter how numerous they may be, mutations do not produce any kind of Evolution". (Grasse, P. P., 1977).
Mutations are a down-hill process and cannot ever lead to an increase in information and complexity of design.
For example, the coelacanth (see picture below - click for larger view) has been dated at 400 million years old yet it is still alive today identical to its fossil ancestors. If dating techniques are correct, then the DNA of the coelacanth (and other living fossils) has made identical copies (or nearly so) of itself for 400 million years! If DNA can be so incredibly accurate in its replication, how can it be so inaccurate as to turn from simple cells of some sort into every living plant, insect, fish, bird, reptile, mammal etc. alive today by chance mutations and selection!
Fossil evidence and mutations. Not only is it difficult to envisage how chance mutations and selection could produce the rich complexity of life on Earth, but there is no fossil evidence we are aware of that shows evidence of extreme abnormalities that must have occurred if mutations are responsible for all the variety of life on Earth. Such abnormalities, on a pure probability basis, should surely be more common that perfectly formed new organisms?
Adaptation. Adaptation can take two forms, involving either the organism adapting its behaviour to respond to its environment or the organism in some way adapting its biological make up in response to its environment.
Behavioural adaptation - Many living creatures have sufficient intelligence to learn new behaviour patterns. Dogs, cats, pigs, rats, monkeys, whales, dolphins, etc. are all examples of intelligent animals capable of learning new behaviour patterns. If a particular learnt behaviour pattern helps a given species of animal to survive, then this behaviour pattern may be passed on to future generations. It could be said that the animal had adapted to its environment. However, this has not led to that animal becoming a totally different organism, although possibly in time it could be classed as a different sub-species of the original species if coupled with physiological changes. The animal has used the intelligence it already had to respond to its environment. Man is the most successful in using his intelligence to adapt to different environments, but this success, rather than leading to new species is actually resulting in the decimation of species at an alarming rate!
Biological adaptation - In Michael Denton's excellent book "Evolution, a theory in crisis" in the chapter entitled "a partial truth" a limited number of examples of diversification and formation of new species are given (Denton, 1985). One example is Hawaiian honeycreepers, which have diversified into twenty-two distinct species and forty-five sub-species. However, he stresses that such variation can not be extrapolated to macro-evolution. In this chapter he comments that geographical isolation of a population is a key event on the road to species formation. However, variation of a kind, even if reproductively unique (see early section on the fruit fly for some comments on this) is a long way off a change from say a fish to an amphibian. Michael Denton also comments in this book that it was not until the 1950's (about 100 years after Darwin's book was published) that there was clear evidence for natural selection actually operating in nature and this was that of the peppered moth (click here for more details). In the 1860's the moth was pale in colour, although a rare dark form was known to exist. During the next 100 years, the dark form became more and more common until eventually the light form was rare. The reason for the selection of one type of moth was said to be pollution. Originally the dark form showed up well against trees with lichen on, so it was easy prey for predators. However, as pollution reduced lichen on trees the light version became more visible and hence was reduced in numbers by predators whilst the dark moth was now better camouflaged. The above scenario is natural selection, but rather than Evolution, it is selection of what was already there To top.
Tiger snakes.A recently observed example of both behavioural and biological adaptation involves the tiger snakes on Chappell Island off the coast of Tasmania. On the Chappell Island, but not on Tasmania, the mutton bird is a protected species, and as such it is a rich source of food for the tiger snakes on Chappell Island but not on Tasmania. On Chappell Island not only have the tiger snakes changed their eating habits, but the tiger snakes grow bigger, have larger jaws (for eating the mutton bird chicks) and larger venom glands than the ones in Tasmania. However, this is limited change, and does not involve one species changing into a totally different one. To top.
Selection.Selection occurs when environmental or other conditions select one species or one type of a species in favour of others. For example, if you add antibiotic to a culture of bacteria, then the antibiotic will select for only those bacteria that are resistant to it. If you kill all butterflies with insecticide except certain resistant strains, then you have selected for resistant butterflies. The adaptation example above of the peppered moth is also an example of natural selection. In these cases, you have only selected what was already there. No new information has been added to the DNA to prove that evolution occurred. At the moment on planet Earth, we are living in such a way that we are selecting predominantly for humans. However, this is resulting in an alarming loss of other species. Selection is not the agent of evolution. It may be the agent for survival of the fittest, but it can give cause to loss of species under adverse conditions where one species out competes others.
Selection is so often seen as part of the evolution story, but it can be more easily explained as an in-built mechanism for organisms to maintain their complex genetic code (e.g. most mutant forms don't survive as they are generally not as good as the original), rather than the mechanism for simpler organisms to become more complex.
The retention of potentially harmful mutations as recessive genes, cumulatively, would quickly swamp any 'useful' mutations and the longer the process continues the worse it gets. This has to be one of the most telling arguments against evolution yet demonstrated. Mutations are a down-hill process and cannot ever lead to an increase in information and complexity of design.To top.
Bacteria.All life according to the theory of evolution is supposed to have evolved from what people used to believe were simple cells (which are now know to be highly complex) of some sort. As bacteria are the simplest single celled organisms on the planet today (that can replicate outside living cells) it is worth considering them and their ability to change.
As bacteria are so small and as some such as Escherichia coli can divide every 20 minutes or so, it is possible to studybillions of bacteria for thousands of generations in a short period of time. Although bacteria are able to gain genes (such as those coding for antibiotic resistance) through processes similar to sexual reproduction, there is no evidence of bacteria ever producing anything else but bacteria.
Bacteria undergo mutation at a rate of between about 1:1,000,000 to 1:1000,000,000 per cell generation. This mutation rate can be increased by subjecting bacteria to certain chemicals or to irradiation. However, many of these mutations will actually harm the bacteria in some way. Even if they do gain resistance to some chemical substance, it will often be at a cost to the general well-being of the bacteria (Saunders, 1984). It should be noted that bacteria (and other living organisms) can only undergo limited mutation. Extensive disruption of the complex genetic code of any living organism will lead to either a horribly miss-formed organism or to a non-viable organism. Whilst genetic engineering is able to introduce genes from one organism to another, this is a complex process done under carefully controlled conditions and is not the result of chance mutations.
Thus bacteria can undergo limited non-lethal mutation, they can adapt to a limited extent to new environments (e.g. where there are antibiotics) and new environments (e.g. antibiotics) can select for specific strains (e.g. antibiotic resistant strains). However, no mutation process has ever been shown in which any bacteria changes from one genus of bacteria to another, let alone to a higher organism such as a protozoan. With respect to antibiotic resistance, there is evidence that antibiotic resistant bacteria existed before antibiotics were used by humans (Saunders, 1984). The use of antibiotics by humans just made these antibiotic resistant strains more common.
To go to a web page of another site where you can download a .pdf file with more information about antibiotic resistance please click here. To top.
Variability within dogs.According to a recent article New Scientist (30th November 2002), all dogs descended from five or fewer female grey wolves that lived 15, 000 years ago. Does such a finding support evolution or belief in creation or intelligent design? Please click here to see some debate on this.
Dogs today are a wonderful example of variability. There are numerous pedigree breeds ranging from miniature breeds to Great Danes. The incredible variety of dogs is extended by virtue of the fact that all dogs can breed with each other so genes can swab around. However, once again this variety represents the genes that already exist. There is no evidence for dogs ever producing anything but different (or similar) types of dogs. Selective breeding may give rise to new breeds of dogs, but not to anything but dogs. The gene pool of dog DNA has been preserved, not added to.
Summary. The above examples of genetic variability, the limited ability to adapt and the selection of the fittest within a pre-existing gene pool can be applied to all living organisms. However, the above does not explain the major changes between say bacteria and amoebae or between land mammals and whales and dolphins. Genetic variability may lead to new sub-species (e.g. as in breeds of dogs, breeds of plants), but not to a totally different organism. At present on planet earth, the survival of the fittest (man?) is resulting in the loss (not gain) of species. To top.
Books - These do not focus specifically on the contents of this page, but all will have some content of direct relevance to this page. All these books can be bought on line at the "Was Darwin right store".