Mutations are changes in genes that take place while they are being copied during reproduction. Point mutations are mutations involving a change in just one nucleotide (a "letter" in DNA language). The following are the changes due to point mutations.
Sickness and malfunction: Most mutations lead to serious illnesses and deformities.
Bigger and better organisms: The protein yield of wheat can increase. This has been found to be due to mutations in genes that control the making of proteins. [Konzak, C. F. (1977). "Genetic control of the content, amino acid composition and processing properties of proteins in wheat", Advances in Genetics, vol 19, pp 407-582]. There are genes responsible for making the protein, and regulatory genes that inhibit the production of the protein after it reaches a certain value. Due to mutations, the regulatory genes are degraded successively, and this prevents them from playing their inhibiting role - thus, higher and higher levels of protein are obtained. The degradation of regulatory genes involves a loss of information, and thus has negative side effects (less starch per seed and less grain per planting - see Brock R. D (1980). "Mutagenesis and Crop Production" in Carlson, P.S., the Biology of Crop Productivity, New York: Academic Press pp. 383-409).
Drug resistance: Antibiotics work by attaching to the ribosomes (protein manufacturing molecular machines) in bacteria. The ribosome then cannot do its job, and the bacteria cannot multiply. If however a mutation occurs, the shape of the ribosome becomes different, and the antibiotic cannot attach to it. There is an important observation to make: several ribosome shapes prevent the antibiotic from attaching. Thus, the mutant ribosome is less specific than the original one, and this means that drug resistance involves a loss of information. Further discussion
New diets: In an experiment [Mortlock, R.P., "Metabolic acquisition through laboratory selection", Annual Review of Microbiology, volume 36, pp. 259-284], researchers denied soil bacteria their usual nutrients, namely, ribitol and D-arabitol, and tried to get them to eat xylitol, a similar molecule that however, does not occur in nature. At first the bacteria starved, but subsequently, a series of three mutants appeared that could digest xylitol with increasing efficiency! Why did the bacteria starve initially? There are three reasons:-
Problem 1: The production of the digestive enzyme RDH is triggered only by the presence of ribitol, so it is not made when only xylitol is present.
Problem 2: Although RDH can help digest xylitol, its activity on xylitol is much less than that on ribitol.
Problem 3: Foreign molecules cannot penetrate through the bacteria's cell walls easily. Ribitol triggers the production of a "permease enzyme" that allows it entry. There is no transport system for xylitol.
So how did the first mutant bacteria work?
Problem 1: A mutation damaged the triggering mechanism for the production of RDH. So although ribitol was absent, RDH was produced uncontrolled.
Problem 2: The large amounts of RDH produced made up for the low activity on xylitol
Problem 3: Although xylitol has no transport mechanism, a small amount does get in by diffusion.
Now for the second mutant:
Problem 1: No further development
Problem 2: Another mutation changed the RDH and made it more active on xylitol. Further investigation showed that the mutant RDH is less specific - it is more active on xylitol and L-arabitol, and less active on ribitol. The original RDH is highly active on ribitol, and very less active on xylitol and L-arabitol
Problem 3: No further development
We also have the third mutant:-
Problem 1: No further development
Problem 2: No further development
Problem 3: A permease enzyme exists for D-arabitol, but its production is triggered only by the presence of D-arabitol. A mutation destroyed the control switch, and thus the enzyme was produced even though no D-arabitol was around. Although this enzyme is intended for D-arabitol, it works on xylitol also, and thus xylitol gets a free ride into the cell.
Notice that in all cases, the mutations involved a loss of information. [I've been very brief here. For a detailed and illuminating description, refer to Lee Spetner, Not by Chance, p148-159]
Non-point mutations are substantial changes to the genome of the organism such as:-
What phenotypic change does this genetic change result in? The following are some examples from bacteria. More research will probably furnish more examples with other organisms.
Drug resistance: The salmonella bacterium demonstrates inversion about once in every 10 generations. This changes the proteins present in it. This helps it avoid the immune system of its host. Drug resistance can also result from transposition.
New enzymes: John Cairns and his team at Harvard University kept some bacteria in lactose. These bacteria had a defect in the gene encoding for lactase (the enzyme that enables the digestion of lactose). So the bacteria starved. But a few of them managed to survive. Cairns concluded that there was a mutation that converted a gene to one that digests lactose. He wrote: "The cells may have mechanisms for choosing which mutations will occur....Bacteria apparently have an extensive armory of such 'cryptic' genes that can be called upon for the metabolism of unusual substrates....E coli turns out to have a cryptic gene that it can call upon to hydrolyse lactose if the usual gene for the purpose has been deleted. The activation requires at least two mutations...That such events ever occur seems almost unbelievable." [See Cairns, J, J. Overbaugh and S. Miller (1988). "The origin of mutants", Nature, volume 335, pp 142-145]
Note: Insertions, transpositions and deletions in the genome, and the switching on or off of sections of the genome amount to shuffling of information already present in the genome.
Here's how we check if an event is random or not:-
We can now understand Cairns using the word "unbelievable". The probability of the mutations occurring randomly was so vanishingly small, that Cairns didn't expect to see it. But there it was - so soon. It is unbelievable if we assume that these mutations are random. On the other hand, there is nothing unbelievable if we assume that the bacteria itself decides what mutation will take place depending on the environment. In another similar experiment, probabilistic calculations showed that it would take more than a hundred thousand years for the mutant bacteria to appear. However, within a few days, forty percent of the bacteria were mutants! [See Hall, B. G., "Evolution in a Petri dish: The evolved beta-galactosidase system as a model for studying acquisitive evolution in the laboratory", Evolutionary Biology, vol 15, pp 85-150.]
Conclusion: Most, if not all, non-point mutations are not random. Organisms have a variety of genetic states built into them - they decide which state to adopt based on the environment. This means that the change in question is being brought about by the use of genetic information that is already present in organisms.
This question is related to the previous one. Remarkable events occurring randomly take place after a long time, but they take place quickly if they are being doctored. If there are a million lottery tickets in the annual lottery, your chance of winning is one in a million. This means you may have to wait a trillion trillion years to win four lotteries in a row. So if you win four times in the next four years, I'll suspect you're rigging the system.
As we've observed above, bacteria mutate extremely rapidly, and this strongly suggests that the mutations are not random. Here's another example of rapid change:-
About 100 finches (a class of birds) were transferred in 1967 from Laysan Island in the Pacific Ocean to a group of four closely spaced islands about three hundred miles away. Within 20 years, the finches had diversified into different species, depending on the island. The image illustrates a similar speciation that Darwin observed [he only saw the descendant species, not the ancestors]
How did this happen? We don't know, since no one was observing the birds closely enough for twenty years. But the high rate of change gives us possible explanations.
Whatever be the case, one thing is sure: twenty years is far too small a time for natural selection and random point mutations to produce significant changes such as increased or decreased beak size.
To summarize: a lot of change in organisms occurs extremely fast.
We have seen that:-
This means that the observed change is:-
In other words, the observed change is:-
Thus, the change we see in organisms is strong evidence against evolution theory (the goo to you kind), and strong evidence in favor of the Bible.