Let me explain. I don't really know the early history of the use of the phrase 'smoking gun.' I assume that there was a point at which it was used in a straightforward way, to mean a 'clearcut case,' an instance where one could easily arrive at the correct conclusion simply by glimpsing an evidential snapshot. The murder was committed by the guy standing over the body and holding the smoking gun.
But by now, the phrase is more often used to make just the opposite point. I wish I had a dollar for every detective story that turns upon the fact that the person caught holding the smoking gun is not, in fact, the one guilty of the murder. Erle Stanley Gardner was especially fond of this narrative device, and so at least every other Perry Mason drama involved Perry's eschewing the superficial evidence and digging deeply enough to discover what really happened.
Of course, Sherlock Holmes' famous dictum, "I never theorize before having all the facts," also applies here. Modern evolutionary theory is a conclusion that seems to accomodate any and all facts, even those that--to a more reasoned and skeptical observer--ought to undermine it (and thus to suggest more profitable research aimed at discovering the truth about life's history).
So, just to be clear, let's lay out a typical 'smoking gun' scenario...
An off-duty policeman is walking past the front of a house when he hears a scream, followed by a single gunshot. He rushes to the front door and bursts through to find a man holding a smoking gun and kneeling over the corpse of a woman with a single gunshot wound. The man protests that he is innocent and that he suprised and fired at another man (who, he claimed, was the actual murderer), but the conscientious policeman arrests him and hauls him off to pokey.
The detective for the defense (whether Perry Mason, Sherlock Holmes, Lord Peter Wimsey, or any other crime investigator worthy of our respect) digs a bit deeper, and finds the following:
The policeman admits that he originally thought the scream he heard was that of a man, not a woman.The accused is released from jail, and his now-validated testimony is used to try to apprehend the actual murderer.
The bullet in the corpse does not match the ballistics of the smoking gun in the hand of the accused, and
The bullet that does match the smoking gun is lodged in the doorframe of the back door of the house, which was open when the policeman entered the front door.
So how does this relate to human Chromosome 2 and its similarity to chimp Chromosomes 2a and 2b?
The common-ancestry scenario proposed by evolutionists depends upon ignoring the extreme improbability of several of its steps. I'll mention three of the most important.
First, although broken chromosomes can fuse, this particular fusion would have had to occur at the place where it is least expected. Broken chromosomes result in sticky ends, which can fuse to other sticky ends (of other broken chromosomes). But such broken chromosomes will almost never fuse with complete, intact chromosomes, and preventing such fusion is a main function of the telomeres. Had human Chromosome 2 evolved by natural processes from two intact chromosomes (in a being ancestral to chimps and humans), it would have been either through a fusion of two telomeres (acknowledged even by evolutionists as virtually impossible) or through fusion of a telomere with a sticky end of a chromosome broken very near the telomere. While not impossible, this latter scenario is extremely unlikely.
This first, unlikely step must not only have occurred, but it must (on an evolutionary view) have occurred not within one of the millions of somatic (body) cells but within the sperm or egg cell. (Eventually, of course, the evolutionary view has this rare event somehow occurring in both gametes--within a single individual--since this is the present-day condition. But evolutionists seem unconcerned by this amassing of improbabilities.) When the chromosome number of one gamete differs from that of the other, the most common results are a nonviable zygote, an embryo that lives, but with a significant deformity or disease, and a viable but infertile offspring. None of these scenarios produce the new, better-adapted species insisted upon by evolutionary theory.
Third, and assuming for the sake of argument that the first two extremely unlikely events took place, this change in the chromosome of a single individual would have had to have swept through the population (the hypothetical population of this ancestral form). Such a "selective sweep" is a favorite fiction of evolutionists, a fiction necessary to their larger project but one for which there is absolutely no evidence, and for which any argument is viciously circular. Generally, the referrent of this selective sweep claim is a single gene mutation, and applying it (in this case) to such a more significant event as a change in chromosome number ought to require (from the evolutionist) a greater level of evidential or logical support. No such support is offered, of course.
In our smoking-gun murder scenario, the problematic evidence came from the wrong scream, the wrong bullet in the body, and the right bullet in the wrong place. In our Chromosome 2 scenario, the problematic evidence includes (at a minimum) three extremely unlikely events--a fusion involving a telomere, its occurence and viability within a gamete, and its sweeping from this first individual through a significant part of a population. The common-ancestry explanation for the origin of human Chromosome 2--while superficially attractive--fails upon closer inspection. The truth about human origins lies elsewhere.