- #1
DaveC426913
Gold Member
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The general consensus I think is that evolution is still occurring in modern times but just being driven by different factors than geography, climate, predation, etc.
But doesn't the process require time as well?
Flora and fauna (including humans) evolve characteristics because of multi-generational reinforcement selectively preferring that trait, cauing it to increase in frequency in the population.
But if the selection drivers change with every generation, or even many times per generation then how does the process result in any long-term accumulation of changes?
For example: we might have evolved an upright posture as we moved from forest to savanna. This would have been reinforced over many, many generations because the same drivers are in place over all those generations.
But in the modern world (and not just the human world) things are changing so fast that the next generation might be facing a whole new set of challenges. As a dumb example, a generation ago, success (and thus breeding) might be facilitated by a head for number-crunching, but now calculators render mental number-crunching a non-advantage, so our
children will choose mates differently.
Even though selection is occurring, it's not occurring over time, so there's no consistency. It's kind of like a heart in fibrillation - it's still beating, it's just pulling in every direction at once, and so gets nowhere.
But doesn't the process require time as well?
Flora and fauna (including humans) evolve characteristics because of multi-generational reinforcement selectively preferring that trait, cauing it to increase in frequency in the population.
But if the selection drivers change with every generation, or even many times per generation then how does the process result in any long-term accumulation of changes?
For example: we might have evolved an upright posture as we moved from forest to savanna. This would have been reinforced over many, many generations because the same drivers are in place over all those generations.
But in the modern world (and not just the human world) things are changing so fast that the next generation might be facing a whole new set of challenges. As a dumb example, a generation ago, success (and thus breeding) might be facilitated by a head for number-crunching, but now calculators render mental number-crunching a non-advantage, so our
children will choose mates differently.
Even though selection is occurring, it's not occurring over time, so there's no consistency. It's kind of like a heart in fibrillation - it's still beating, it's just pulling in every direction at once, and so gets nowhere.