本篇文章共分 6 段，從開花植物，亦即被子植物在演化上大量出現開始，進而探討其演化來源，並整理目前學界所提出來的起源論述，以說明這種目前植物界佔絕大比例的植物進化之謎。

本篇考題英文原文與對應之中文翻譯整理如下。練習作答解題時若有對語意不清楚之處，請仔細查閱對照，以提升閱讀理解能力。

Evolution of the Flowering Plants 開花植物的進化

1. 開花植物進化成謎

   Many aspects of the history of flowering plants (angiosperms) remain mysterious. Evidence of the earliest angiosperms comes from fossilized leaves, stems, fruits, pollen, and, very rarely, flowers. In addition, there has been much study of modern plant morphology (structure) and genetics in order to determine which living species might be most closely related to the ancient ancestors of angiosperms. Despite intensive efforts for over 200 years, scientists have still not reached consensus on which type of plant was the ancestor to the angiosperms, and when and where the angiosperms first evolved. Indeed, Charles Darwin himself called the origin of the flowering plants an “abominable mystery.”

   開花植物（被子植物）的歷史在許多方面仍然維持神秘。最早的被子植物的證據來自於葉、莖、果實、花粉，以及非常罕見的花朵的化石。此外，人們對現代植物形態學（結構）和遺傳學進行了大量研究，以確定哪些生物物種可能與被子植物的古老祖先關係最密切。儘管經過 200 多年的努力，科學家們仍未就哪種類型的植物是被子植物的祖先，以及被子植物何時何地首次進化達成共識。事實上，查爾斯．達爾文本人稱有花植物的起源是一個「可惡的謎」。

2. 被子植物的未知起源

   What type of plant was the ancestor to the angiosperms? Most botanists now agree that the flowering plants are monophyletic in origin, meaning that they evolved from a common ancestor. Some paleontologists have suggested that the common ancestor may have been a type of cycad (palmlike tropical plants). Other paleontologists maintain that the angiosperms may have evolved from seed-bearing ferns. Finally, analysis of the morphological traits of some primitive living plants suggests that the ancestor may have been related to the modern pines. The question of angiosperm ancestry remains unresolved.

   什麼類型的植物是被子植物的祖先？大多數植物學家現在都同意，有花植物的起源是單系的，也就是說，它們是從一個共同的祖先演變而來的。一些古生物學家認為，這個共同的祖先可能是一種蘇鐵植物（類似於棕櫚的熱帶植物）。其他古生物學家堅持認為，被子植物可能是由帶種子的蕨類植物進化而來。最後，對一些原始活體植物的形態特徵的分析顯示，其祖先可能與現代松樹有關。被子植物的祖先問題仍未解決。

3. 被子植物的爆炸性成長

   The time and place of the first appearance of flowering plants have long been a topic of great interest. There is good fossil evidence that early angiosperms, including a number resembling modern magnolias, were present in the Early Cretaceous geologic period (more than 100 million years ago). Angiosperms became increasingly abundant during this period. Between 100 million and 65 million years ago, a period known as the Late Cretaceous, angiosperms increased from less than 1 percent of flora (plant life) to well over 50 percent. Many of the modern plant families appeared during this time period. In the Early Tertiary period which followed, angiosperms increased to comprise 90 percent or more of Earth's total flora. Where did these successful plants first originate and spread from?

   長期以來，開花植物首次出現的時間和地點是一個非常令人感興趣的話題。有充分的化石證據顯示，早期的被子植物，包括一些類似於現代木蘭的植物，在早白堊紀地質時期（超過 1 億年前）就已經出現。在此一時期，被子植物變得越來越豐富。在 1 億年前到 6,500 萬年前，也就是被稱為白堊紀晚期的時期，被子植物從占植物群（植物生命）的不到 1% 增加到遠遠超過 50%。許多現代植物家族都是在這一時期出現的。在隨後的第三紀早期時期，被子植物增加到佔地球植物群總數的 90% 或更多。這些成功的植物最初是從哪裡起源和傳播的？

4. 被子植物源於赤道地區說

   Analysis of the fossil leaf structure and geographic distribution of the earliest Cretaceous angiosperms has led many biogeographers to conclude that they evolved in the tropics and then migrated poleward. It is known that angiosperms did not become dominant in the high latitudes until the Late Cretaceous. Paleontologists have recovered fossil angiosperm leaves, stems, and pollen from Early Cretaceous deposits in eastern South America and western Africa. These two continents were joined together as part of Gondwanaland, one of two supercontinents that existed at that time. The locations of these early angiosperm finds would have been close to the equator during the Early Cretaceous and are conformable with a model by which angiosperms spread from the tropics poleward.

   對最早的白堊紀被子植物的葉子結構和地理分佈的分析，使許多生物地理學家得出結論：它們在熱帶地區進化，然後向極地遷移。眾所周知，被子植物直到白堊紀晚期才在高緯度地區成為主導。古生物學家在南美東部和非洲西部的白堊紀早期礦床中找到了被子植物的葉子、莖和花粉化石。這兩個大陸作為岡瓦納大陸的一部分結合在一起，是當時存在的兩個超級大陸之一。這些早期被子植物的發現地點在白堊紀早期時應該是靠近赤道的，符合被子植物從熱帶向極地傳播的模式。

5. 被子植物源於南太平洋說

   Not all botanists agree with an African-South American center for the evolution and dispersal of the angiosperms, pointing out that many of the most primitive forms of flowering plants are found in the South Pacific, including portions of Fiji, New Caledonia, New Guinea, eastern Australia, and the Malay Archipelago. Recent genetic research has identified the rare tropical shrub Amborella as being the living plant most closely related to the ancient ancestor of all the angiosperms. This small shrub, which has tiny yellow-white flowers and red fruit, is found only on New Caledonia, a group of islands in the South Pacific. Many botanists conclude that the best explanation for the large numbers of primitive living angiosperms in the South Pacific region is that this is where the flowering plants first evolved and these modern species are relics of this early evolution. Comparisons of the DNA of Amborella and many hundreds of species of flowering plants suggest that the first angiosperm arose and the development of separate species occurred about 135 million years ago.

   並非所有的植物學家都同意以非洲-南美為被子植物進化和傳播的中心，他們指出，許多最原始的開花植物形式在南太平洋發現，包括斐濟、新加勒多尼亞、新幾內亞、澳大利亞東部和馬來群島的部分地區。最近的遺傳學研究發現，罕見的熱帶灌木 Amborella 是與所有被子植物的古老祖先關係最密切的活體植物。這種小灌木有細小的黃白色花朵和紅色果實，只在南太平洋的一組島嶼上發現到，即新加勒多尼亞。許多植物學家得出結論，對南太平洋地區大量原始被子植物的最佳解釋是，這裡是有花植物最初進化的地方，這些現代物種是這種早期進化的遺跡。對 Amborella 和許多數百種開花植物的 DNA 比較顯示，第一個被子植物的出現和獨立物種的發展發生在大約 1.35 億年前。

6. 被子植物源於亞洲北部說

   Recently discovered fossils complicate our understanding of the origin of the angiosperms even further. Paleontologists from China have found beautifully preserved fossils of an angiosperm plant, including flowers and seeds, in Jurassic period deposits from China. The site, which is about 130 million years old, is near modern Beijing. The new fossil plant found at the site is now the oldest known angiosperm. The age of the fossils and the very primitive features of the flowers have led the discoverers to suggest that the earliest flowering plants may have evolved in northern Asia.

   最近發現的化石使我們對被子植物的起源的理解更加複雜。來自中國的古生物學家在中國侏羅紀時期的沉積物中發現了保存精美的被子植物化石，包括花和種子。該遺址約有 1.3 億年的歷史，位於現代北京附近。在該遺址發現的新植物化石是目前已知最古老的被子植物。化石的年齡和花的非常原始的特徵使發現者認為最早的開花植物可能是在亞洲北部演化的。