4-4 翻譯 從圖4-6下方開始

原文: In reproductive isolation, mutation and change by natural selection operate independently in the gene pools of geographically isolated populations. If this process continues long enough, members of the isolated populations may become so different in genetic makeup that they cannot produce live, fertile offspring if they are rejoined. Then one species has become two, and speciation has occurred(Figure4-6). For some rapidly reproducing organisms, this type of speciation may occur within hundreds of years. For most species, it takes from tens of thousands to millions of years-making it difficult to observe and document the appearance of a new species.
Extinction Is Forever
Another process affecting the number and types of species on the earth is extinction, in which an entire species ceases to exist. Species that are found in only one area are called endemic species and are especially vulnerable to extinction. They exist on islands and in other unique small areas, especially in tropical rain forests where most species are highly specialized.
翻譯: 在再生的隔離過程中，透過自然選擇的變化和變化在地理上隔離的人口的基因文庫獨立操作。 如果這個過程繼續足夠長的時間， 成員的被孤立的人口變得可能如此不同在他們不能生育的遺傳學構造內住，繁殖力強的後代他們再接合。 然後，一種類變得兩，物種形成發生(Figure4-6) . 一些迅速複製的生物體，物種形成可能在數百年內發生的這類。 大多數種類，取自數以萬計給數百萬年做困難觀察和資料一新種類的出現。
永遠滅絕
影響種類的數目和類型的另一個過程在地球上是滅絕，其中一個整個種類停止存在。 被在只有一個地區發現的種類被叫為地方性的種類並且特別易受滅絕。 他們靠島生存，和在其他獨特的小的地區裡，特別是大多數種類高度專業化的熱帶雨林。