時差N小時:果實成熟(上)

　　Usually a green, sour fruit is just afruit that’s not ripe yet. If you left a lime on the tree longer would it eventually change colorand become sweet, like an orange? Actually, limes do become much more yellow and less souras they ripen. Under ripe limes are darker green and quite bitter. There are other clues to theirripeness too. Ripe limes are heavy with juice and more aromatic, with a fragrant “limey”smell. Most fruits we eat use similar cues to advertise ripeness.But why? Why would plantswant parts of them to be eaten? Fruiting plants have evolved a partnership with certainanimals in order to increase the success of their seeds. Tasty fruit pulp is the reward plantsoffer to animals in exchange for dispersing their seeds.

　　通常，一個綠色、酸味的水果還沒成熟。如果你將酸橙留在樹上，它最終會改變顏色，口味變甜嗎?就像桔子那樣嗎?其實，酸橙成熟時確實變得更加黃，味道也不那么酸了。未成熟時，顏色變得深綠，味道也更苦。成熟也可其他方面看出來，成熟的酸橙果汁飽滿，氣味更芳香味。大部分我們吃的水果使用類似的方面來鑒定成熟度。d但是為什么?植物為什么會希望其中自身的一部分被吃掉?結果的植物進已經(jīng)進化成與某些動物的關系來增加其種子的存活率。可口的水果是獎勵動物們散播種子的回報。