狗的起源：三万年的“狼”变之旅与人类的情感羁绊
在人类浩瀚的文明史中，有一种伙伴始终与我们并肩同行——那就是狗。从冰雪荒原上的野狼，到城市街角的宠物犬，这段跨越三万年的驯化旅程，不仅改变了动物的命运，也深刻地塑造了人类自身。科学家通过DNA分析与化石研究，揭开了狗的起源之谜：它们并非被人类“收编”，而是主动选择与我们共生。从狩猎到守护，从陪伴到救援，狗早已融入人类生活的每一个角落。如今，回望这段从狼到狗的演化史，我们不仅在寻找一种动物的过去，更在追溯一段关于信任、忠诚与情感的永恒故事。
In the vast tapestry of human civilization, one companion has walked beside us every step of the way — the dog.
From the wild wolves of the frozen plains to the loyal pets curled up on our sofas, this 30,000-year journey of domestication has reshaped not only the fate of an animal but also the destiny of humankind.
Genetic studies and fossil discoveries reveal a surprising truth: humans didn’t tame dogs — dogs chose us. “Wolves gone mild” began scavenging near early human camps, and over millennia, this fragile truce blossomed into the most enduring interspecies bond on Earth.
From hunters to herders, from guardians to companions, dogs have become woven into the very fabric of our daily lives.
To trace the origins of dogs is to rediscover the story of loyalty, survival, and the quiet evolution of friendship that continues to shape who we are today.
Narrator： There’s about 7.4 billion people on Earth today…and over 200 million dogs. 当今地球上约有74亿人……还有超过两亿只狗。
——>> So exactly where, when, and why did warm-hearted wolves join our pack? 那么，究竟是在哪里、何时、为何，那些热心肠的狼加入了我们的队伍？
——>> And who trained who? 又是谁训练了谁？
Narrator： [OPEN] So Cat person? Or dog person? 那么，你是猫派，还是狗派？
——>> Me? I’m totally impartial. 我吗？我可是完全中立的。
——>> No matter where you sit—siiiiiiit, it’s plain to see that the histories of dogs and humans are intertwined maybe like no other two species. 不管你站哪一边——坐下～——有一点显而易见：人类与狗的历史，或许比任何两个物种都更紧密相连。
Narrator： If we take domestication out of the human equation, it’s estimated just 1 or 2 million of us would be around today. 如果去掉“驯化”这件事，人类至今可能只剩一两百万个个体。
——>> And of all those animal alliances, our relationship with dogs is the oldest. 而在所有与动物的联盟中，我们与狗的关系最为古老。
——>> But figuring out why, where, and when domestic dogs first originated is still a bone of contention. 但要弄清家犬最早出现的原因、地点与时间，仍是一个争论不休的问题。
Narrator： Why? Is the easiest to answer. “为什么？”——这是最容易回答的。
——>> Every continent is home to wild canids—like Africa’s painted dogs or Asia’s dholes, 每个大陆上都有野生犬科动物——比如非洲彩绘犬、或亚洲豺。
——>> but thanks to genetic research we know modern pups didn’t descend from those local species. 但得益于基因研究，我们知道现代狗并非这些地方物种的后代。
Narrator： Today’s domestic dogs all trace their DNA back to ancient wolves. 现代家犬的DNA可一直追溯到远古的狼。
——>> You may have heard that wolves and ancient people were hunting buddies that used teamwork to run down bigger prey. 你或许听过这样的说法：狼与远古人类曾是狩猎伙伴，携手捕猎大型猎物。
——>> That’s a nice story, but wolf packs can hunt just fine on their own—and usually aren’t too big on sharing. 听起来挺浪漫，但狼群本身就能很好地猎食——而且它们可不太爱分享。
——>> Plus, early humans tended to kill off most carnivorous competition. 再说，早期人类通常会干掉其他食肉竞争者。
Narrator： It’s most likely that humans didn’t adopt dogs. Dogs adopted us. 最有可能的情况是——不是人类收养了狗，而是狗选择了我们。
——>> Any “wolves gone mild” that were tolerant of humans could have scrounged our scraps. 那些性情温和、愿意接近人类的狼，能从我们留下的残羹剩饭中生存。
——>> They didn’t need us, but our leftovers could have made their lives easier. 它们并不依赖我们，但人类的剩饭让生活轻松不少。
Narrator： Today, about 85 percent of domestic dogs still survive on our waste—no matter how many times we tell them “STAY OUT OF THE TRASH.” 如今，约85%的家犬依然靠人类的垃圾维生——无论我们多少次喊它们“别翻垃圾桶！”
Narrator： But a tame wolf isn’t a dog, and scientists are still trying to figure out when and where that change occurred. 然而，一只被驯服的狼并不等于狗，科学家们仍在追寻那场改变究竟何时、何地发生。
——>> Studying living wolves tells us the line that led to our pups is extinct today, 通过研究现存的狼，我们知道通往家犬的那支谱系早已灭绝，
——>> but we can still find their footprints in modern dog genomes. 但我们仍能在现代狗的基因组中找到它们的足迹。
Narrator： Looking at DNA in mitochondria tells us dogs split from their wolf ancestors somewhere in Europe between 19 and 32 thousand years ago, 线粒体DNA显示，狗可能在一万九千到三万二千年前于欧洲从狼中分化出来；
——>> but whole genomes from dozens of living dogs put the split somewhere in South Asia around 33,000 years ago. 但对数十种现存犬类基因组的分析又指向南亚，时间大约三万三千年前。
——>> It’s tough to pin down because dog genes have mixed so much. 由于犬类基因混合频繁，确切结论仍难定论。
Narrator： Fossils don’t tell the whole story either, because bones alone can’t tell us when the thing that looked like a wolf started to act like a dog. 化石也讲不全这个故事——仅凭骨头，我们无法判断那“看似狼”的生物何时开始“像狗”一样行事。
——>> But combining the two, fossils and DNA, could give us some hints. 但若把化石与DNA结合，也许能得到一些线索。
Narrator： DNA extracted from ancient dog fossils has suggested a new story: the domestication split happened in two places, at least 12,000 years ago. 从古代犬类化石中提取的DNA揭示了一个新故事：驯化分化至少在一万两千年前、且在两个地方发生。
——>> And then at some point, Eastern dogs followed people west, and became the dominant ancestor of our canine compadres. 之后，东方的犬类随人类向西迁徙，成为现代犬的主要祖先。
Narrator： Dogs became useful herders, sled pullers, and guards—against predators AND neighboring human tribes. 狗逐渐成为人类的牧者、雪橇拉手与守卫——既防猛兽，也防邻族。
——>> And in a pinch, they could have served as an emergency food supply. 在绝境时，它们甚至可能成为人类的应急食物来源。
——>> Dogs probably saved us more times than we can count. 狗或许拯救过人类的次数，多得数不清。
Narrator： We’re paying them back—pups now have access to insurance, healthcare, some even have more Instagram followers than you and me. 如今我们也在回报它们——狗狗们有保险、有医疗，有的甚至比你我还有更多Instagram粉丝。
Narrator： From a wolf mold, we’ve crafted 340 or so dog breeds, even a few weird ones. 从狼的原型中，我们造出了约340种犬类，甚至包括一些相当奇怪的品种。
——>> It’s hard to believe every domestic dog is still part of the same species, one whose story is so tightly wound to our own, that we still can’t quite tell where it begins. 难以置信，所有家犬仍属于同一物种——它们的故事与人类的命运紧密交织，以至于我们仍无法分清故事的起点。
Narrator： Stay! Staaaay. Curious. 待着！好孩子……保持好奇。
