猴群中的生活（2019）

即使经过50年的观察，
even after 50 years of observation,
日常生活中的小谜团继续提供新的启示
the small everyday mysteries continue to provide new revelations.
今天，沃夫冈正在寻找其中一只雌性
today, Wolfgang is looking for one of the females
来自池塘的 波塔附近的团队
from the group near the pond Pointa.
几天前，
a couple of days ago,
突然她带着一个很小的婴儿出现了，
suddenly she turns up with this really young infant,
不可能超过两周大
couldn't have been more than two weeks old.
她是怎么做到的，这是个谜
how she got that is a mystery.
已看到波塔
Pointa was seen
抱着和照顾这个孩子
carrying and caring for this baby
24小时工作至少两天
round the clock for at least two days.
但沃尔夫冈知道，她自己的孩子最近去世了
but Wolfgang knows her own baby had recently died.
婴儿显然不属于波塔，
the infant obviously did not belong to Pointa,
尽管波塔对它表现得很母性
although Pointa behaved very maternally towards it.
但是她所有的关心和保护中，
but for all her care and protection,
她不能产奶，
she couldn't produce milk,
婴儿绝望了
and the infant was desperate.
它做了些什么
it did something
这对于那个年龄的婴儿来说是不寻常的
that's unusual for an infant of that age.
它开始寻找森林地面上的食物
it began to forage on foods found on the forest floor.
沃尔夫冈急切地想知道，孩子是否活着
Wolfgang is anxious to see whether the baby's still alive.
婴儿不太可能活下来
it's unlikely the infant could survive
没有妈妈的奶水
without its mother's milk.
啊，波塔
ah, there's Pointa.
而且她没有孩子
and she does not have the infant.
几天来，波塔已经竭尽所能了
for days, Pointa had done all she could.
沃尔夫冈从未见过猴子投入这么多--
Wolfgang has never seen a monkey invest so much
在一个不是自己的婴儿身上
in a completely unrelated infant.
这不是一个简单的解释
that doesn't have an easy explanation.
我的意思是，你应该自己抱孩子，是的，
I mean, you should pick up your own infants, yes,
大量投入，促进它们的生存，
invest a lot and promote their survival,
把你的基因传给后代
pass your genes on to the future generations.
它们为什么要为别人的孩子做这些
why are they doing this for somebody else's infant
它们甚至不知道？
that they don't even know?
那一定是互惠利他主义，你知道的
that must be reciprocal altruism, you know.
它们这样做是因为在社会的某个时刻，
they do that sort of thing because at some point in time within society,
这种行为会得到回报，
that kind of behavior will be reciprocated,
所以通过参与这种利他主义行为，
so by participating in this sort of altruistic act,
它的基因留在群体中
the genes for it stay in the population
因为最终它会让你或你的孩子受益
because eventually it will benefit you or your children.
在人类社会中，
in human society,
互惠利他主义是指无关的人
reciprocal altruism means an unrelated person
从他人无私的善举中获益匪浅
benefits greatly from another's unselfish act of kindness.
这是一种复杂的进化策略
it's a sophisticated evolutionary strategy
这意味着社会整体受益
that means society benefits overall.
我们已经开始在黑猩猩等高等动物中认识到这一点
we have started to recognize it in higher animals like chimps.
但波塔在照顾无关婴儿
but Pointa's care of the unrelated infant
表明此行为
suggests this behavior
可能比我们想象的要追溯得更远
may go back further than we think.
到1972年，
by 1972,
沃尔夫冈全神贯注于他的研究
Wolfgang had become deeply engrossed in his research.
他呆的时间比计划的18个月要长得多
he'd stayed much longer than the planned 18 months.
但史密森尼学会的钱快花光了
but the Smithsonian money was running out.
他不情愿地离开猴子回美国去了
reluctantly, he left the monkeys to go back to America.
他无法停止思考
he couldn't stop thinking
关于失踪年轻雌性的秘密
about the mystery of the missing young females.
他开始起草一种理论
he began to formulate a theory.
雌性婴儿的缺乏
could this dearth of female infants
由故意的策略引起
be caused by an intentional strategy
在婴儿早期偏爱雄性？
to favor males in early infancy?
雄性的体形是雌性的两倍
males grow up to twice the size of females.
它们需要高大强壮
they need to be big and strong
当它们长大成人时，
by the time they become young adults,
当它们就得离开母亲的猴群
when they have to leave their mother's group
在一支新的队伍中寻找伴侣
to find mates in a new troop.
新猴群中的原先居住的雄性
the resident males in the new group
会嫉妒地保护它们的雌性
jealously guard their females.
即将到来的雄性有被杀死的风险
incoming males risk being killed.
只有强壮的雄性，像多米，
only strong males, like Domi,
能成功加入一支新的队伍
will succeed in joining a new troop
并繁殖后代
and siring offspring.
给一个儿子投入的时间往往
so the time to invest in a son
处于婴儿期，
is in infancy,
帮助它快速成长
helping him to grow quickly
增加它成功的几率
and increase his odds of success.
一个女儿一生都和她母亲的猴群在一起，
a daughter stays with her mother's troop her whole life,
以缓慢的、稳定的速度繁殖
reproducing at a slow, steady pace.
她从母亲的投入中受益
she benefits from her mother's investment
贯穿她的生活中
throughout her life.
但，婴儿时期，
but, as infants,
女儿有点被忽视了
daughters are somewhat neglected.
因此，它们中有更多的在年幼时早逝
as a result, more of them die young.
这是一个理论，
It was a theory,
但是数据会支持沃尔夫冈的预判吗？
but would the numbers back up Wolfgang's hunch?
经过三年半的数据收集
after three and a half years gathering data
在近500只猴子身上，
on nearly 500 monkeys,
他接近解锁--
he was close to unlocking
失踪雌性婴儿的秘密
the mystery of the missing infant females.
这些数字能证实整个猕猴数量
would the numbers confirm that entire populations
区别对待雄性和雌性婴儿？
treat male and female infants differently?
右侧，黑白，
right there, in black and white,
不可否认，有数据说明
there was the data, undeniably.
雄性和雌性出生的数量相等
males and females were born in equal numbers.
但超过一半的女儿在第一年就去世了；
but more than half of daughters died in their first year;
而三分之二的儿子还活着
whereas two thirds of sons were surviving.
我没有犯错误
I hadn't made a mistake
我早期选择的团队
with my early selection of groups.
这是一个真实的模式
it's a real pattern.
雄性，然后，出现死亡率高峰
males, then, had a mortality spike
6岁或7岁时，
at age 6 or 7,
就在它们开始分散和战斗的时候
right when they start dispersing and fighting.
总体，当它们成年时，
overall, by the time they're adults,
猕猴数量中男女的平衡
the balance of males and females in a population
平衡
evens out.
沃尔夫冈的数据揭示了一个关键因素
Wolfgang's data revealed a key factor
影响着每一只小猴子的生活
affecting the life of every young monkey.
所以，今天，
so, today,
当我们看到像德克斯特这样的年轻雄性受到青睐时，
when we see young males, like Dexter here, being favored,
而拉拉被忽略了，
while lala is ignored,
我们知道为什么
we know why.
母亲在婴儿身上投资更多
mothers invest more in their infant sons
忽视它们的女儿，
and neglect their infant daughters,
甚至可以为雄性生产更丰富的乳汁--
even to the extent of producing richer milk for males--
我们现在知道，这在人类身上也是真实的
something we now know to also be true in humans.
就像有一幅巨大的马赛克图片
it's like having a huge mosaic picture
然后这些部件开始装配在一起
and the pieces started fitting together.
部分要感谢它母亲的帮助，
thanks in part to his mother's help,
伊莫泰尔正在成为一名成功的雄性
Imotel is well on his way to being a successful male.
它8岁了
he's 8 years old.
它出生在一个高级家庭
he was born into a high-ranking family
在另一群组猴群中，
in another troop,
但却离开了池塘加入了这个团体
but has left to join this group by the pond.
年轻雄性的分散
this dispersal of young males
是猕猴混合基因池的方式
is the macaque's way of mixing the gene pool
防止近亲繁殖
and preventing inbreeding.
在与当地雄性进行了八个月的战斗后，
after eight months of fighting with the resident males,
伊莫泰尔最终被接受
Imotel has finally been accepted
现在可以给雌性进行梳理
and is now allowed to groom the females.
突然，伊莫泰尔的前一群组
suddenly, Imotel's former group
出现在它们领土的边缘
appears on the edge of their territory.