人类的大脑是世界上最复杂的器官之一
The human brain is one of the most sophisticated organs in the world,
一个由数十亿神经元组成的超级计算机
a supercomputer made of billions of neurons
控制我们所有的感观、
that processes and controls all of our senses, thoughts, and actions.
思维和行动但是查尔斯.达尔文发现了更引人瞩目的东西：
But there was something Charles Darwin found even more impressive:
那就是蚂蚁的大脑
the brain of an ant,
他称其为世界上最不可思议的原子构成物之一
which he called one of the most marvelous atoms of matter in the world.
这么小的生物却拥有如此复杂的大脑
If you find it hard to believe that something so tiny
真令人难以置信
could have a complex brain,
这样想的不只你一个
you’re not alone.
瑞典自然学家 卡尔.林奈
In his project to classify and describe all living things,
在分类和描述生物时 认为昆虫根本没有大脑
Swedish naturalist Carl Linnaeus assumed insects had no brains at all.
虽然他错了
He was wrong, but understandably so.
但情有可原昆虫的大脑不仅极其微小
Insect brains are not only miniscule,
而且在很多方面 与我们大脑的工作方式完全不同
but in many respects, they function differently than our own.
最显而易见的区别之一
One of the most noticeable differences
就是一只没了头的昆虫仍然能够爬行、
is that an insect that loses its head can still walk,
挠痒、
scratch itself,
呼吸、
breathe,
甚至飞行
and even fly.
我们神经系统的运作
This is because while our nervous system works like a monarchy,
好比君主制由大脑发号施令
with the brain calling the shots,
而昆虫的神经系统却像分权制那样运行
the insect nervous system works more like a decentralized federation.
昆虫的许多活动 比如爬行或者呼吸
Many insect activities, like walking or breathing,
都由贯穿身体的神经元群处理
are coordinated by clusters of neurons, also known as ganglia,
也就是神经节
along their bodies.
各部位的神经节与大脑一起 构成了昆虫的神经系统
Together with the brain, these local ganglia form the insect nervous system.
尽管昆虫可以依靠神经节进行生命活动
While an insect can do a lot with just its local ganglia,
对它的生存来说 大脑依旧不可或缺
the brain is still crucial for its survival.
昆虫的大脑让它通过视觉和嗅觉来感知世界
An insect’s brain lets it perceive the world through sight and smell.
选择合适的配偶
It also chooses suitable mates,
记住食物和巢穴的位置
remembers locations of food sources and hives,
进行有效的沟通
regulates communication,
甚至在长途跋涉时辨别方向
and even coordinates navigation over huge distances.
上述种种行为
And this vast diversity of behaviors
都由一个针尖大的器官控制
is controlled by an organ the size of the head of a pin,
里面的神经元不超过一百万
with less than one million neurons,
而我们人类 有860亿神经元
compared to our 86 billion.
虽然昆虫与人类大脑的组成大相径庭
But even though the insect brain is organized very differently from ours,
但是仍有很多惊人的相似之处比如说
there are some striking similarities.
大部分昆虫的触须都有气味感受器
For example, most insects have smell detectors on their antennae,
与人类的鼻子功能相似
similar to those found in human noses.
并且嗅觉对应的脑区形态和功能也十分相似
And our primary olfactory brain regions look and function rather similarly,
通过精确地在特定时间激活和钝化神经元群
with clusters of neurons activated and deactivated in precise timing
来为气味命名
to code for specific scents.
由于昆虫和人类并非近亲
Scientists have been astonished by these similarities
二者的相似之处让科学家十分惊奇事实上
because insects and humans are not very closely related.
二者最近的共同祖先已是距今约为五百万年前
In fact, our last common ancestor was a simple worm-like creature
一种的类似蠕虫的生物
that lived more than 500 million years ago.
二者的进化历程自此便分道扬镳
So how did we end up with such similar brain structures
那为什么我们还有如此相似的大脑结构呢？
when our evolution took almost entirely different paths?
科学家称这种现象“趋同进化”同理
Scientists call this phenomenon convergent evolution.
鸟类、蝙蝠和蜜蜂各自进化出了翅膀
It’s the same principle behind birds, bats, and bees separately evolving wings.
相似的生存压力能引起自然选择
Similar selective pressures can cause natural selection
使进化历程迥然不同的物种
to favor the same evolutionary strategy
采用同样的进化策略
in species with vastly different evolutionary pasts.
通过比较昆虫和人类的大脑
By studying the comparison between insect and human brains,
科学家能发现哪些功能是我们的大脑独有的
scientists can thus understand which of our brain functions are unique,
哪些是生存压力的通解
and which are general solutions to evolutionary problems.
但这不是科学家着迷于昆虫大脑的唯一原因
But this is not the only reason scientists are fascinated by insect brains.
它们小而简单 所以理解神经元的如何工作
Their small size and simplicity makes it easier to understand
就比较容易了
exactly how neurons work together in the brain.
这对工程师来说也很可贵
This is also valuable for engineers,
因为他们能根据昆虫大脑设计控制系统
who study the insect brain to help design control systems
包括无人飞机和微型搜救机器人所以
for everything from self-flying airplanes to tiny search-and-rescue roach bots.
大小和复杂性不是唯一让人印象深刻的东西
So, size and complexity are not always the most impressive things.
以后你再打苍蝇
The next time you try to swat a fly,
先花三秒钟瞻仰一下它的神经系统
take a moment to marvel at the efficiency of its tiny nervous system
因为它比你的还好
as it outsmarts your fancy brain.