单系群

现行的稻蝗亚科并非一单系群，而是一多系群。

The current Oxyinae is not a monophyletic group , and should be a polyphyletic group .

属；（2）该单系群内的姐妹群既有重迭分布又有隔离分布，因此该单系群现有的地理分布格局很可能既源于扩散事件又源于离散事件；

Therefore the generic distribution pattern of the monophyletic group maybe have resulted from both dispersal and vicariance events .

结果表明：红豆杉科与三尖杉科均为单系群，二者互为姐妹群；

According to the tree , Taxaceae and Cephalotaxaceae are monophyletic groups , and the sister group relationship between the two families was confirmed .

但非致病性辣椒疫霉菌的群体遗传多样性比致病性的要高，这说明致病性菌株可能是单系群起源。

But the population of pathogenic isolates was less diverse than that of the nonpathogenic isolates , suggesting that the pathogenic isolates was monophyletic origin .