Begging by nestlings (TPO11) - 英檢

最後一段

最後一句

Because close relatives have many of the same genes,
animals that harm their close relatives may in effect be destroying some of
their own genes.Therefore, a begging nestling that secures food at the expense
of its siblings might actually leave behind fewer copies of its genes overall
than it might otherwise.

請問一下紅色句子該怎麼解釋?

看不太懂

尤其是than it might otherwise

感謝回答


--