For example, most insects have smell detectors on their antennae, similar to those found in human noses. 比如说，大部分昆虫的触须都有气味感受器，与人类的鼻子功能相似。

　　And our primary olfactory brain regions look and function rather similarly,  并且嗅觉对应的脑区形态和功能也十分相似，

　　with clusters of neurons activated and deactivated in precise timing to code for specific scents. 通过精确地在特定时间激活和钝化神经元群来为气味命名。

　　Scientists have been astonished by these similarities because insects and humans are not very closely related. 由于昆虫和人类并非近亲，二者的相似之处让科学家十分惊奇。

　　In fact, our last common ancestor was a simple worm-like creature that lived more than 500 million years ago. 事实上，二者最近的共同祖先已是距今约为五亿年前的一种类似蠕虫的生物。

　　So how did we end up with such similar brain structures when our evolution took almost entirely different paths? 二者的进化历程自此便分道扬镳，那为什么我们还有如此相似的大脑结构呢？

　　Scientists call this phenomenon convergent evolution. 科学家称这种现象“趋同进化”。

　　It's the same principle behind birds, bats, and bees separately evolving wings. 同理，鸟类、蝙蝠和蜜蜂各自进化出了翅膀。

　　Similar selective pressures can cause natural selection to favor the same evolutionary strategy in species with vastly different evolutionary pasts. 相似的生存压力能引起自然选择，使进化历程迥然不同的物种采用同样的进化策略。

　　By studying the comparison between insect and human brains, 通过比较昆虫和人类的大脑，

　　scientists can thus understand which of our brain functions are unique, and which are general solutions to evolutionary problems. 科学家能发现哪些功能是我们的大脑独有的，哪些是生存压力的通解。

　　But this is not the only reason scientists are fascinated by insect brains. 但这不是科学家着迷于昆虫大脑的唯一原因。

　　Their small size and simplicity makes it easier to understand exactly how neurons work together in the brain. 它们小而简单，所以理解神经元的如何工作就比较容易了。

　　This is also valuable for engineers, 这对工程师来说也很可贵，

　　who study the insect brain to help design control systems for everything from self-flying airplanes to tiny search-and-rescue roach bots. 因为他们能根据昆虫大脑设计控制系统，包括无人飞机和微型搜救机器人。

　　So, size and complexity are not always the most impressive things. 所以，大小和复杂性不是唯一让人印象深刻的东西。

　　The next time you try to swat a fly, take a moment to marvel at the efficiency of its tiny nervous system as it outsmarts your fancy brain. 以后你再打苍蝇，先花三秒钟瞻仰一下它的神经系统，因为它比你的还好。