wordiology

I know its not a word, really. But seriously, people get completely bent out of shape about "inventing" words. Really? All words are invented. In my view, I would rather a word be invented instead of co opting another word and re-tasking it. So, wordiology. Word study, or word philosophy. (Which to the Greeks, who had -logy first, was study/science/philosophy--there wasn't a real distinction then...)
I spend a lot of time getting annoyed by people who use different words to mean the same thing. I was listening to Talk of the Nation this morning, they were talking about business world slang. Some of it was very interesting. Personally, I think its businesspeople wanting to have their own jargon (spake the bio major...), but this is beside the point. There are so many ways of describing things and everyone has their own context for a word. In business, a contractor is someone who works on a by-contract basis. In construction, a contractor is something much more specific.
You see this a lot if you're in a specialized field. Laymen will use your jargon and take it literally, or worse, misunderstand something that doesn't appear in the common use lexicon. I mean, if I started talking about ecosystem relations, niche predators, and tertiary consumers, most people would have half a clue as to what those are, but wouldn't necessarily understand the intricacies. There is nothing wrong with this, but its the fact that many people think they get it since they have an inkling of understanding. It is the unwillingness to admit to ignorance of a complex subject that is frustrating.
This comes to the forefront with subjects like evolution. Scientists don't use the word "theory" like laymen do. To a layman, a "theory" is your idea of how something works, with maybe a little evidence thrown in. To a scientist, a "theory" is how something works in all observed cases, but since all cases haven't been observed, there may be an exception or aberration. So when someone says, oh, evolution is just a theory---well, yeah. So is gravity. But no one has ever seen gravity not work unless there was another force involved (such as lift). Same case with evolution. There are very few species where a family tree cannot be drawn back into other species, and those that can't are researched intensely by those in evolutionary science. The other issue is that often things can get personified: 'X' changed in this way because it was better suited to this environment. Not how it works. For those who would like to know, here's the short version:
In any population, there is a range of genetic diversity. This occurs from random genetic mutation, which is a side effect of imperfect gene copying. If the mutation is not harmful the individual, (in that, kill it before it can breed sort of way) it will be passed on to that individuals offspring and take a place in the gene pool. These mutations can be anything, from things you can't see externally, like sickle cell anemia, to very obvious things, like albinism. Some of them are completely arbitrary, like a widows peak, a cleft chin, or tongue curling. These are all monogenic (dominant/recessive) traits in humans, and don't really have an effect on our "fitness".
But lets look at albinism. In most cases, around the world, being pure white is not so good. Its really hard to blend in to the forest, grasslands, swamp, etc, when one is white. It can also leave the individual more susceptible to skin damage from the sun (polar bears have black skin under all that fur for this reason). So when a genetic mutation for albinism appears, it is unlikely that it is going to be very common, since that individual is not liable to live long enough to reproduce, being easy to spot by predators and by prey. But suppose our white friend is an arctic creature. A white animal would blend in much better with snow and ice. In this case, the individual would be ideally suited to the environment, and would likely be healthy and live a long life, and hence produce more offspring. Since it passes its genes on to the next generation, a portion of these offspring will also be white. These offspring will be able to out-compete their darker colored siblings, and will be more likely to breed as well. Over time, the albinism gene would spread throughout the population, until the whole species had the albinism gene--and, ta-da: evolution.
This is a simple good/not good scenario for mutation. A more complex one would be sickle cell anemia, which is a monogenetic syndrome which effects the structure of hemoglobin in the blood. If one has both of the recessive sickle cell genes, one has sickle cell. If, other other hand, one has only one or none of the sickle cell genes, then one is normal.

S = normal gene       s = sickle cell gene

SS = normal individual
Ss = unlikely to show symptoms of sickle cell
ss = sickle cell patient

Sickle cell can kill, but it is extremely prevalent in tropical populations. Why would a potentially deadly gene be so widespread? It is because the heterozygous individual (Ss) is resistant to malaria, which is abundant in the tropics. The heterozygous expresses both genes, but in most cases, the "good" gene can make up for the "defective" one. If one looks at Mendelian genetics, it shows that of all of the children a heterozygous couple can have (both Ss):

    S   s
S SS Ss
s Ss ss

one will be sickle cell, one won't have the gene but will be susceptible to malaria, and two will be sickle cell carriers and resistant to malaria. To mother nature, two out of four ain't bad, and so that is what gets passed on.
This stuff can take some thought, but its not really difficult to understand. The easiest examples are bacteria, or populations decimated by disease. Wipe out a major portion of the population, and whatever could survive that destructive force will reproduce and create a new population resistant to whatever that force was, be it antibiotics or the bubonic plague.
I think this is all fascinating, but alot of people don't understand it, and don't want to.

to be continued?