Dá / ěr / wén / de / lǐ / lùn / jiě / shì / le / tiān / zé / rú / hé / yǐng / xiǎng / wù / zhǒng / de / biàn / huà。达尔文的理论解释了天择如何影响物种的变化。Darwin's theory explains how natural selection affects changes in species.