一个难句理解

Biologist:
Some speculate that the unusually high frequency of small goats found in island populations is a response to evolutionary pressure to increase the number of goats so as to ensure a diverse gene pool. However, only the reproductive success of a trait influences its frequency in a population. So, the only kind of evolutionary pressure that can reduce the average size of the members of a goat population is that resulting from small goats achieving greater reproductive success than their larger cousins.

to increase the number of goats 修饰哪一个？

so as to ensure a diverse gene pool是不是to increase的目的状语。

that是什么意思，替代pressure？

achieving是做small goats的定语，还是result from的动名词宾语？？

achieving是做small goats的定语，还是result from的动名词宾语？？

做small goats的定语

我觉得achieving是result from的宾语。

不管他是宾语还是定语, achieve这个动作都是由small goats来做.

result from后应跟个名词或者动名词, 但这个动名词又要有个主语来引导, 那么就只好result from small goats achieving了.

是，对理解没有影响。如果是动名词宾语的话，small goats 应该用所有格吧。