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POPSVarying Environments Can Speed Up Evolution Using computer simulations, we find that evolution toward goals that change over time can, in certain cases, dramatically speed up evolution compared with evolution toward a fixed goal. The highest speedup is found under modularly varying goals, in which goals change over time such that each new goal shares some of the subproblems with the previous goal. The speedup increases with the complexity of the goal: the harder the problem, the larger the speedup. Modularly varying goals seem to push populations away from local fitness maxima, and guide them toward evolvable and modular solutions. This study suggests that varying environments might significantly contribute to the speed of natural evolution.
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POPSGirls entering puberty by the age of six - but are drugs the answer?
"Early puberty has even been linked to watching too much television. A few years ago, Italian scientists found that children who watched three hours a day produced less of the sleep hormone melatonin - low levels of the hormone play an important role in the timing of puberty. But perhaps more worrying is the theory that it's exposure to environmental chemicals which is causing the drop in the age of puberty. These chemicals mimic the effect of hormones, disrupting the normal timing of sexual maturing. Whatever the cause, growing numbers of children are being deprived of childhood and are turning, physically, into mini-adults at an increasingly young age. But without the emotional maturity to deal with these changes, they are vulnerable to exploitation. In Britain, it is now estimated that up to at least one in six children under ten is affected. Indeed, there is a belief that schoolgirls as young as six are entering puberty".
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