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翻译人员: Tianshu Wang
校对人员: Yuyang Zhao
00:06
The human brain is one of the most
sophisticated organs in the world,
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人类的大脑是世界上最复杂的器官之一,
00:11
a supercomputer made of billions
of neurons
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一个由数十亿神经元组成的超级计算机,
00:14
that processes and controls all
of our senses, thoughts, and actions.
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控制我们所有的感观、思维和行动。
00:19
But there was something Charles Darwin
found even more impressive:
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但是查尔斯.达尔文发现了更引人瞩目的东西:
00:23
the brain of an ant,
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那就是蚂蚁的大脑。
00:25
which he called one of the most
marvelous atoms of matter in the world.
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他称其为世界上最不可思议的原子构成物之一。
00:30
If you find it hard to believe that
something so tiny
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这么小的生物
却拥有如此复杂的大脑
00:35
could have a complex brain,
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真令人难以置信,
00:36
you're not alone.
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这样想的不只你一个。
00:37
In his project to classify and describe
all living things,
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瑞典自然学家 卡尔.林奈
在分类和描述生物时,
00:41
Swedish naturalist Carl Linnaeus
assumed insects had no brains at all.
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认为昆虫根本没有大脑。
00:47
He was wrong, but understandably so.
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虽然他错了,但情有可原。
00:51
Insect brains are not only miniscule,
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昆虫的大脑不仅极其微小,
00:53
but in many respects,
they function differently than our own.
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而且在很多方面,
与我们大脑的工作方式完全不同。
00:57
One of the most noticeable differences
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最显而易见的区别之一
00:59
is that an insect that loses its head
can still walk,
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就是一只没了头的昆虫
仍然能够爬行、
01:04
scratch itself,
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挠痒、
01:05
breathe,
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呼吸、
01:06
and even fly.
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甚至飞行。
我们神经系统的运作
好比君主制,
01:08
This is because while our nervous system
works like a monarchy,
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01:11
with the brain calling the shots,
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由大脑发号施令,
01:13
the insect nervous system works
more like a decentralized federation.
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而昆虫的神经系统
却像分权制那样运行。
01:18
Many insect activities,
like walking or breathing,
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昆虫的许多活动, 比如爬行或者呼吸,
01:21
are coordinated by clusters of neurons,
also known as ganglia,
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都由贯穿身体的神经元群处理,
01:26
along their bodies.
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也就是神经节。
01:28
Together with the brain, these local
ganglia form the insect nervous system.
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各部位的神经节
与大脑一起,构成了昆虫的神经系统。
01:33
While an insect can do a lot with just
its local ganglia,
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尽管昆虫可以依靠神经节
进行生命活动,
01:37
the brain is still crucial
for its survival.
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对它的生存来说,大脑依旧不可或缺。
01:39
An insect's brain lets it perceive
the world through sight and smell.
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昆虫的大脑让它
通过视觉和嗅觉来感知世界,
01:43
It also chooses suitable mates,
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选择合适的配偶,
01:45
remembers locations of food sources
and hives,
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记住食物和巢穴的位置,
01:48
regulates communication,
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进行有效的沟通,
01:50
and even coordinates navigation
over huge distances.
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甚至在长途跋涉时辨别方向。
01:54
And this vast diversity of behaviors
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上述种种行为
01:57
is controlled by an organ
the size of the head of a pin,
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都由一个针尖大的器官控制,
02:01
with less than one million neurons,
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里面的神经元不超过一百万,
02:03
compared to our 86 billion.
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而我们人类,有860亿神经元。
02:06
But even though the insect brain
is organized very differently from ours,
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虽然昆虫与人类
大脑的组成大相径庭,
02:10
there are some striking similarities.
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但是仍有很多惊人的相似之处。
02:13
For example, most insects have
smell detectors on their antennae,
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比如说,大部分昆虫的触须
都有气味感受器,
02:17
similar to those found in human noses.
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与人类的鼻子功能相似。
02:20
And our primary olfactory brain regions
look and function rather similarly,
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并且嗅觉对应的脑区
形态和功能也十分相似,
02:25
with clusters of neurons activated
and deactivated in precise timing
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通过精确地在特定时间
激活和钝化神经元群
02:30
to code for specific scents.
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来为气味命名。
02:33
Scientists have been astonished
by these similarities
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由于昆虫和人类并非近亲,
02:36
because insects and humans are not
very closely related.
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二者的相似之处
让科学家十分惊奇。
02:40
In fact, our last common ancestor
was a simple worm-like creature
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事实上,二者最近的共同祖先
已是距今约为五百万年前
02:44
that lived more than 500 million
years ago.
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一种的类似蠕虫的生物。
02:47
So how did we end up
with such similar brain structures
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二者的进化历程自此便分道扬镳,
02:50
when our evolution took almost
entirely different paths?
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那为什么我们还有
如此相似的大脑结构呢?
02:54
Scientists call this phenomenon
convergent evolution.
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科学家称这种现象“趋同进化”。
02:58
It's the same principle behind birds,
bats, and bees separately evolving wings.
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同理,鸟类、蝙蝠和蜜蜂
各自进化出了翅膀。
03:04
Similar selective pressures can cause
natural selection
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相似的生存压力
能引起自然选择,
03:07
to favor the same evolutionary strategy
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使进化历程迥然不同的物种
03:10
in species with vastly different
evolutionary pasts.
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采用同样的进化策略。
03:14
By studying the comparison between
insect and human brains,
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通过比较昆虫和人类的大脑,
03:18
scientists can thus understand which of
our brain functions are unique,
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科学家能发现
哪些功能是我们的大脑独有的,
03:23
and which are general solutions
to evolutionary problems.
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哪些是生存压力的通解。
03:27
But this is not the only reason scientists
are fascinated by insect brains.
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但这不是科学家
着迷于昆虫大脑的唯一原因。
03:32
Their small size and simplicity makes it
easier to understand
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它们小而简单,所以理解
神经元的如何工作
03:36
exactly how neurons work together
in the brain.
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就比较容易了。
03:40
This is also valuable for engineers,
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这对工程师来说也很可贵,
03:41
who study the insect brain to help design
control systems
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因为他们能根据昆虫大脑
设计控制系统,
03:46
for everything from self-flying airplanes
to tiny search-and-rescue roach bots.
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包括无人飞机和微型搜救机器人。
03:52
So, size and complexity are not always
the most impressive things.
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所以,大小和复杂性
不是唯一让人印象深刻的东西。
03:56
The next time you try to swat a fly,
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以后你再打苍蝇,
03:58
take a moment to marvel at the efficiency
of its tiny nervous system
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先花三秒钟
瞻仰一下它的神经系统,
04:03
as it outsmarts your fancy brain.
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因为它比你的还好。
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