单词	anagenesis
释义	anagenesis /ˌanəˈdʒɛnɪsɪs / noun [mass noun] Biology Species formation without branching of the evolutionary line of descent.Evolutionary taxonomists such as Simpson use both cladogenesis and anagenesis in their classifications, arguing that taxonomic groups should be based on the branching points in evolution and the degree of difference between groups.... For this reason, it should come as little surprise that proponents of a hierarchical approach to macroevolution do not consider anagenesis to be the dominant mode of species transformation. This process of organic transformation includes anagenesis as well as cladogenesis. Derivatives anagenetic /ˌanədʒəˈnɛtɪk/ adjective ... Darwin, who viewed natural selection as a process producing slow anagenetic changes along lines of descent, thought that species were arbitrary slices. Species defined in these anagenetic terms have neither discrete temporal boundaries nor a sufficient level of constancy during their evolutionary tenures. In the first case, i.e. a new anagenetic evolutionary trend, a complete reversal of the direction of natural selection should be assumed. Origin Late 19th century: from ana- and genesis.
随便看	the ball of the foot the ball of the thumb Theban the Bank of Mum and Dad the Bar the Bard the Bard of Avon the bare bones thebe the be-all and end-all the Bear the Beatitudes the beautiful game the beautiful people the Beehive the bee's knees the beginning of the end the benefit of the doubt the Berg the Bermudas Thebes the best-laid plans of mice and men gang aft agley the best of both (or all possible) worlds the best of three (or five etc.) the best (or the pick) of the bunch

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