请各位高手帮忙翻译一本英文书的一些内容,书名叫做《The international b...
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发布时间：2024-09-26 23:21
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热心网友
时间：2024-10-28 14:32
At best fragmentary, our knowledge of plant evolution is based solely on fossils. Some light has been shed by the painstaking study of the fossil evidence, but most fossils are no more than impressions of stems or leaves of soft, perishable plants which have been trapped in sedimentary rock. Trees constitute an exception. Silica, quartz or other minerals may fill the centres of tree tissue cells and in so doing preserve the cellulose wall. Vast petrified forests formed in this manner survive in many parts of the world with all their anatomical detail intact.
我们对植物进化的知识完全只基于对化石的研究，充其量只是零碎的信息。我们对化石证据煞费苦心的研究确实获得一些启迪，但大多数化石所显示的只不过是受困于沉积岩中的柔软和易变质植物的茎或叶的印记而已。树木是个例外。由于树木的组织细胞中心可能充斥着硅石、石英或其他矿物，因此树木的纤维素壁得以保存。以这种方式形成的石化森林，大面积地幸存于世界各地，它们结构的细节都完整无缺地保留下来。
The first thousand million years of plant evolution were slow. Single-celled plants languished in the primeval seas, while a layer of life-supporting oxygen gradually formed above them. Once sufficient oxygen screened the land from the harmful rays of the sun, an explosion of terrestrial plant life began.
植物的初始十亿年进化是缓慢的。单细胞的植物在原始的浩瀚大海里失去活力，而在它们的上方正逐渐形成一层维持生命的氧气。当氧气的积累足以抵挡太阳的有害射线后，陆生植物开始了爆发性的生长。
The first true land plants appeared some 450 million years ago. They had no true leaves or roots, but from them the first species large enough to be described as trees emerged at the middle of the Devonian period. They were small by comparison with modern forest trees, but by the late Devonian period giant mosses and ferns had evolved more than a hundred feet high.
第一种真正的陆生植物大约出现在四亿五千万年前。这些植物没有真正的叶子或根部，不过，第一个体型足于被称为树的种类显现在泥盆纪时代的中期。它们比现代森林的大树相对较小；然而，到了泥盆纪晚期，苔藓及蕨类植物已演变成高于一百英尺。
The development of male and female gametes and reproduction of seeds, instead of spores, were two important evolutionary steps which brought plant life close to its modern form. During the Carboniferous period, or Coal Age, the gymnosperms, early relatives of the conifers, the cycads and the ginkgos began to appear, although lower vascular plants dominated the swamp forests until the mass extinctions of the Permian period, 280 million years ago.
使植物变得接近于现代形状的两大重要进化的步骤是雌雄生殖细胞的发展以及种子而不是孢子的繁殖。在石炭纪或煤炭时代，尽管维管束植物遍布当时的沼泽林，松柏类的早期亲戚，裸子植物类、苏铁类及银杏树却开始出现；直至两亿八千万年前，维管束植物才大规模地灭绝。
The dominance of gymnosperms was complete by the Cretaceous period – by which time angiosperms, the flowering plants which dominate the world’s flora today, were coming into being. Subsequent large climatic and geological shifts brought about angiosperm dissemination and the decline of the gymnosperms – their empire reduced to the colder temperate and northern regions of the world, where they reign today.
到了白垩纪时期，这是裸子植物类的鼎盛繁殖期，而控制现今世界植物群的有花植物 – 被子植物类也初露身影。随后而至的大规模气候变化及地质改变促使被子植物的播散，以及裸子植物的衰退，它们的王国被削减至现在盛行于地球较冷的温带及北方地区。
热心网友
时间：2024-10-28 14:33
热心网友
时间：2024-10-28 14:36
