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(单词翻译:双击或拖选)
Lancewoods And Moas Long Gone Like animals, plants evolve by adapting to their surroundings. For example, New Zealand’s lancewood tree has evolved to defend itself against being eaten by the moa–a large, flightless bird related to the emu and ostrich1. Scientists speculate that as a tiny seedling2, the lancewood grows small brown leaves that help the infant tree blend in with leaf litter on the forest floor. So a prowling moa might pass by and spare the plant. As it grows, the lancewood’s leaves change, becoming long and spiky3, with barbs4 along the edges. Scientists believe that bright spots near the barbs are probably meant to get moas’ attention and make them think twice about trying to swallow such a prickly meal. Finally, when they reach adulthood5, the lancewood’s leaves change once again, becoming rounder and losing their spikes6. Why? Perhaps because the tree is now tall enough to hoist7 its leaves out of the reach of hungry moas. Now, what’s especially interesting about all this is that while the lancewood tree still thrives in New Zealand, moas were hunted to extinction8 around five-hundred years ago. But the trees they once dined upon still go about their business as though the birds were still a threat. So what is this mean? First, that scientists can really only speculate about why the lancewood behaves the way it does. But it also suggests that to really understand a plant’s evolution, we have to consider not only its current environment but also its past. Defenses evolved against now-extinct predators9 may still shape a plant’s appearance and behavior today.
1 ostrich | |
n.鸵鸟 | |
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2 seedling | |
n.秧苗,树苗 | |
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3 spiky | |
adj.长而尖的,大钉似的 | |
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4 barbs | |
n.(箭头、鱼钩等的)倒钩( barb的名词复数 );带刺的话;毕露的锋芒;钩状毛 | |
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5 adulthood | |
n.成年,成人期 | |
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6 spikes | |
n.穗( spike的名词复数 );跑鞋;(防滑)鞋钉;尖状物v.加烈酒于( spike的第三人称单数 );偷偷地给某人的饮料加入(更多)酒精( 或药物);把尖状物钉入;打乱某人的计划 | |
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7 hoist | |
n.升高,起重机,推动;v.升起,升高,举起 | |
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8 extinction | |
n.熄灭,消亡,消灭,灭绝,绝种 | |
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9 predators | |
n.食肉动物( predator的名词复数 );奴役他人者(尤指在财务或性关系方面) | |
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