時差N小時:果實成熟(下)

　　Plants attract fruit eaters，or “frugivores”–by packingvaluable resources into their fruits like sugar andwater or important nutrients such as carotenoids,vitamins and minerals. Plants often target specificanimals that will give their seeds the best chancesfor germination, and discourage or repel animalsthat won’t. Plants that want to attract birds ratherthan mammals might produce thorns or have fruitsthat taste unpalatable to most mammals but tastyto birds. Plants that want to repel birds but attractmammals might have fruits with thicker, tougherouter skins. Don’t forget that selective breeding by humans has dramatically changed manyfruits from their wild state, often resulting in larger, sweeter fruits with fewer seeds.

　　通過為吃果實的動物提供富含營養(yǎng)的果實，比如：糖，水或類胡蘿卜素，維他命和礦物質等重要成分，植物來吸引吃果實的動物。植物往往以特定的動物為特定目標，那些動物會使植物種子有發(fā)芽的最佳機會，反之，則會阻止或擊退其他對種子發(fā)芽不利的動物。要吸引鳥類而不是吸引哺乳動物的植物，可能會帶刺或結出對多數哺乳類動物難吃，但對鳥類美味的果實。想吸引哺乳動物的植物而不是鳥類的植物，結出的水果可能有更厚，更粗糙的外皮。不要忘了人類選擇性育種已戲劇性地改變了許多水果，將植物的野生狀態(tài)改變成果實較大，口味更甜，籽更少的果實。