In 50,000 years earth will enter into another glacial period regardless of current global warming effects.

不管目前的全球变暖效应如何，五万年后地球将进入另一个冰川。

Within that, you have cycles of “glacial periods” and “interglacial periods”.

其中，你有“冰” 和“间冰” 的循环。

So let’s look at the Pleistocene Epoch — the most recent glacial period.

那么让来看看更世时——最近的冰川。

" We obviously don't have thermometers in the glacial period, so we have to instead look for these kinds of stand-in indicators."

“显然，在冰川时没有温度计，因此须寻找这些替代指示器。”

6 million years ago, the ice caps expanded even more, and the Earth entered a glacial period.

260万年前， 冰盖进一步扩大，地球进入冰河。

Imagine how much surviving the cold would have been a problem back in a glacial period.

想象一下，在冰川时， 如何在寒冷中幸存下来是个问题。

Glacial periods over the past 6 million years promoted the selection of a set of genes responsible for the metabolism and neurohormonal regulation in cold conditions.

过去 600 万年的冰促进了一组基因的选择，这些基因负责在寒冷条件下的陈代谢和神经激素调节。

Just such an influx may have happened about 12,800 years ago, helping to set off a thousand-year glacial period called the Younger Dryas.

大约 12,800 年前可能就发生了这样的涌入，帮助引发了称为木的千年冰川。

Somehow, Gigantopithecus managed to survive the first few of these glacial periods, but 100 thousand years ago, in the Middle Pleistocene, something changed.

不知何故， 巨猿设法在这些冰河时的前几个时幸存下来，但在 10 万年前的中更世，情况发生了变化。

Glacial periods are colder and have a greater ice sheet presence, while the interglacial periods are warmer and more like the Earth is now.

冰川更冷， 冰盖更大， 而间冰更暖，更像现在的地球。

The decrease in the rain-and snow-fall since the close of the glacial period in the Sierra is much less than is commonly guessed.

自塞拉利昂冰川结束以来降雨和降雪量的减少比通常猜测的要少得多。

All the Sierra rivers and their tributaries in these high regions are thus lost every winter, as if another glacial period had come on.

因此，每年冬天，这些高地的所有塞拉利昂河及其支流都消失了， 仿佛又一个冰河来临了。

Perhaps more than a mile in average depth has the range been thus degraded during the last glacial period, -a quantity of mechanical work almost inconceivably great.

在最后一次冰河时，山脉的平均深度可能超过一英里，因此退化了——大量的机械工作几乎大得令人难以置信。

When the most recent glacial period ended around 11,700 years ago, things got warmer and drier, and the swamps and lakes that Castoroides depended on became more scarce.

当最近一次冰川在大约 11,700 年前结束时，天气变得更加温暖和干燥， Castoroides 赖以生存的沼泽和湖泊变得更加稀少。

Next to the Cathedral Rocks on the south side towers the Sentinel Rock to a height of more than 3000 feet, a telling monument of the glacial period.

在南侧的大教堂岩石旁边耸立着高达 3000 多英尺的哨兵岩石，这是冰河时的一座纪念碑。

As an example, I have attempted to show how potent has been the influence of the Glacial period on the distribution of the same and of allied species throughout the world.

作为一个例子， 试图说明冰河时对世界各地相同物种和近缘物种分布的影响有多大。

It is hard without long and loving study to realize the magnitude of the work done on these mountains during the last glacial period by glaciers, which are only streams of closely compacted snow-crystals.

如果不进行长而热情的研究，就很难认识到冰川在最后一次冰河时对这些山脉所做的工作的重要性，冰川只是紧密压实的雪晶流。

How long the various species of wild bees have lived in this honey-garden, nobody knows; probably ever since the main body of the present flora gained possession of the land, toward the close of the glacial period.

没有人知道各种野蜂在这个蜜园里生活了多久；可能自从现在的植物群的主体占领了这片土地，到冰川结束时。

At the close of the last glacial period, the middle and foot-hill regions also abounded in lakes, all of which have long since vanished as completely as the magnificent ancient glaciers that brought them into existence.

在末次冰川结束时，中山和山麓地区还盛产湖泊，但这些湖泊早已完全消失，就像孕育它的壮丽的远古冰川一样。