60秒科学:蝴蝶也懂药材 自我治疗伤病

人类的许多药材资源都来自于植物，而根据种种事例显示，人类并非植物药材的唯一受益物种，许多动物也会寻找特定的植物来治疗自身伤病。

Infected monarch¹ butterflies will lay their eggs on plants that contain a chemical that can protect the butterflies' offspring. Cynthia Graber reports

Many of our medicines originate in plants. But we’re not the only ones who tap into nature. There’s increasing evidence that some animals seek out specific plants for their medicinal qualities. A new study shows that monarch butterflies may be among them.

Monarch butterflies—famous for their U.S.–Mexico migration—feed on dozens of species of milkweed. Some milkweeds have a higher concentration of chemicals called cardenolides, which make the butterflies toxic² to predators³. Research had focused on whether the monarch’s chose different milkweeds to hurt their enemies.

But Emory University’s Jaap de Roode wondered if the choice might be related to a parasite⁴ that’s passed from mother to offspring, with fatal results: “What we do find is that the monarchs⁵ prefer to lay their eggs on the medicinal species when they are infected. However, when they are not infected with the parasite, they do not prefer this species over this one, they lay their eggs equally between these two species.

So somehow they know that they’re infected and they know what to do about it.” The research was published in the journal Ecology Letters. [Thierry Lefèvre et al., "Evidence for trans-generational medication in nature"]

Co-author Mark Hunter notes that watching animal choices could offer clues about what plants might contain potential medicines for us.

—Cynthia Graber
 

1 monarch   

n.帝王，君主，最高统治者

参考例句：

• The monarch's role is purely ceremonial.君主纯粹是个礼仪职位。
• I think myself happier now than the greatest monarch upon earth.我觉得这个时候比世界上什么帝王都快乐。

2 toxic   

adj.有毒的，因中毒引起的

参考例句：

• The factory had accidentally released a quantity of toxic waste into the sea.这家工厂意外泄漏大量有毒废物到海中。
• There is a risk that toxic chemicals might be blasted into the atmosphere.爆炸后有毒化学物质可能会进入大气层。

3 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）

参考例句：

• birds and their earthbound predators 鸟和地面上捕食它们的动物
• The eyes of predators are highly sensitive to the slightest movement. 捕食性动物的眼睛能感觉到最细小的动静。 来自《简明英汉词典》

4 parasite   

n.寄生虫；寄生菌；食客

参考例句：

• The lazy man was a parasite on his family.那懒汉是家里的寄生虫。
• I don't want to be a parasite.I must earn my own way in life.我不想做寄生虫，我要自己养活自己。

5 monarchs   

君主，帝王( monarch的名词复数 )

参考例句：

• Monarchs ruled England for centuries. 世袭君主统治英格兰有许多世纪。
• Serving six monarchs of his native Great Britain, he has served all men's freedom and dignity. 他在大不列颠本国为六位君王服务，也为全人类的自由和尊严服务。 来自演讲部分