white-back duck meaning in English
劳动布
Examples
- Phylogenetic analysis surports that anseranas should be placed in monotypic family anseranatidae , and the whistling ducks and the white - backed duck should be separated from subfamily anserinae and placed them into family dendrocygnidae . the family anatidae could be classified into two subfamilies , anserinae and anatinae . the results approve that the swans should be put into the tribe cygnini of subfamily anserinae as suggested by livezey ( 1996 , 1997b ) and the shelducks should be placed in the tribe tadornini of subfamily anatinae , therefore , our results do not support sibley and ahlquist ' s ( 1990 ) establishment of the subfamily cygninae and placing the shelducks in the tribe anserini
研究结果表明： 1 )雁形目鸟类12srrna基因有较多的碱基插入和缺失，碱基转换数高于颠换数； 2 )赞同将鹊鹅( anseranas )置于鹊鹅科( anseranatidae )中，树鸭( dendrocygna )应从雁亚科( anserinae )中独立出来设立树鸭科( dendrocygnidae ) ，白背鸭( thalassornis )隶属于树鸭科； 3 )鸭科( anatidae )可分为雁亚科和鸭亚科( anatinae ) 2个亚科，不赞同sibley & ahlquist ( 1990 )设立天鹅亚科( cygninae )及将麻鸭归入雁族( anserini )的观点，支持livezey ( 1996a ， 1997b )的观点建议将天鹅类归为雁亚科天鹅族( cygnini ) ，麻鸭置于鸭亚科下麻鸭族； 4 )在鸭亚科内的系统发生上，潜鸭最早分歧出来，麻鸭、海中文摘要鸭及栖鸭彼此iaj的亲缘关系较近；河鸭族为一单系发生群，在系统演化中形成独立的一支。