Serpent » July 13th, 2018, 5:27 pm wrote:wolfhnd » July 13th, 2018, 1:51 pm wrote:I think the fear of being accused of being anthropocentric is distorting this discussion. No where in the discussion did I suggest that humans were the most "evolved" species.
I didn't suggest that you had. I do maintain that many discussions do rest on that notion, and that the word "direction" tends to encourage such a notion.The only thing that needs to be acknowledged is that the organisms that can from the primordial soup had molecular complexity greater than the local environment.
Otherwise, it wouldn't be living - or distinguishable from its surroundings. But it' only at that point that evolution begins.A related topic is if complexity reduces stability. It appears to be a universal rule.
Perhaps not directly, since it usually presents in tiny increments. But any change is risky: an individual that differs from the norm may have a slight advantage over its rivals in feeding but be rejected by its species, or operate outside its safety-zone, and circumstances could change back so that the advantage is lost again. And increased complexity is usually costly - in maintenance, in over-specialization, in the loss of another ability.As it relates to evolution it has been suggested that this rule is captured by the phrase evolved to evolve. This concept also cause great confusion because it seems to imply design.
I don't get that implication - but then, I don't get any meaning from that phrase. Does it mean genetically volatile? In a period of transition from one set of environmental conditions to another? Or not highly specialized?The adaptation of pathogens to antibiotics has been studied to determine the adaptive mechanism. It would be tempting to assume that the "better designed" individuals would adapt more efficiently but that is not what we find.
I find this confusing, as well. How do you tell which is the "better-designed" individual among germs? For that matter, how are individual germs identified at all?What we find is that genetic diversity is lower in populations not stressed by antibiotics.
That would be the stable population.Genetic variation is suppressed by the fact that mutations tend to be out competed.
Of course. In normal circumstances, genetic variation does not have a positive effect: it would subdivide the species. Only a very small percent of mutations are beneficial; many are detrimental, some are fatal.As the population starts to die off a small number of less stable individuals survive increasing genetic diversity because of an increased mutation rate.
It all depends on what they're becoming fitted to. Any sudden, drastic change in environment usually kills off large portions of the population, if not the entire species. If there is one variant that can survive the change, it becomes the new template. If there are two or more variants that can survive the change, they begin to compete for dominance. Now there are very few bacteria, so there is lot of scope for filling the niche. There may just be one winner crowding out the others, or there may arise two new sub-species.If this sounds like it contradicts survival of the fittest it is only because the way language is normally used follows different rules.
The problem there, as it very often is in such discussions, is multi-purpose words. We need to be careful to define the terms we're using, and how those terms are used in the given context. If a word has a different meaning in another context, it's too easy to transpose it from one to the other.
(That, btw, is a common misdirection stratagem of some debaters, and a common fallacy in logic.)