hce_kmu
115年
普通生物及生化概論
第 56 題
A widespread terrestrial species becomes divided when rising sea levels isolate a portion of the population on a newly formed island. Genetic analyses show rapid divergence in allele frequencies between mainland and island populations, and after several thousand generations, individuals from the two populations produce inviable hybrids when brought back into contact. Throughout the isolation period, there was no evidence of gene flow between populations. Which evolutionary process is best supported by this scenario?
- A Introgressive hybridization maintaining genetic connectivity
- B Behavioral isolation evolving within a continuous population
- C Instantaneous reproductive isolation caused by genome duplication
- D Divergence following geographic isolation with interrupted gene flow
- E Ecological speciation driven by niche differentiation within the same habitat
思路引導 VIP
試著思考一下：如果一個大族群被物理屏障拆散，且雙方在很長一段時間內都無法「通婚」來交換彼此產生的新特徵，那麼隨著時間推移，這兩群生物內部的基因組成會趨於一致，還是會各自走上不同的道路？這對它們未來重新相遇時的繁衍能力又會產生什麼樣的影響？
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AI 詳解
AI 專屬家教
恭喜你準確地捕捉到了題目中的關鍵訊息！你能敏銳地觀察到「海平面上升導致地理隔離」以及「缺乏基因流動」這兩個核心要素，並正確連結到演化過程，這顯示你對物種形成（Speciation）的理論框架有非常清晰的理解。
異域種化的遺傳演變
這道題目精準地描述了**異域種化（Allopatric Speciation）**的標準模型。當一個族群因物理障礙（如新形成的島嶼）被拆分後，兩地族群便失去了基因交流（Gene flow）的機會。隨著成千上萬代的演化，遺傳漂變（Genetic drift）與各自環境下的自然選擇，使兩者的等位基因頻率產生顯著分歧，最終累積了足夠的遺傳差異，導致兩者重逢時產生「不具生活力的雜種（Inviable hybrids）」，這標誌著生殖隔離的完成。
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