It looks like flightlessness evolved among the ratites at least six times independently, which is very surprising.

看起来平胸类鸟群无法飞行是至少独立进化六次的结果，这是非常令人惊讶的。

For birds that nest or feed on the ground, this predisposition to flightlessness can be even stronger.

对于在地面上筑巢或觅食的鸟类，这种不会飞的倾向可能更强烈。

Most often, flightlessness evolves after a bird species flies to an island where there are no predators.

大多数情况下，在鸟类飞到没有捕食者的岛屿后，会出现不会飞的情况。

Surprising because it means that each of these big flightless birds-the elephant bird group included-seemed to take its own winding path to flightlessness and bigness.

令人惊讶，因为这意味着每一种不会飞的大型鸟——包括象鸟在内——似乎都经历了变得不会飞、变得更大的曲折道路。

Researchers sequenced the Galapagos cormorant's genome to find out how its flightlessness evolved They found changes in the function of hair-like cellular structures called cilia.

研究人员对加拉帕戈斯鸬鹚的基因组进行了测序，以了解其不会飞的能力是如何进化而来的。他们发现了称为纤毛的毛发状细胞结构的功能发生了变化。

So in spite of the energy-saving advantages of flightlessness, many flightless bird species have only a short run before going the way of the dodo.

因此，尽管不会飞具有节能优势，但许多不会飞的鸟类在走上渡渡鸟的道路之前只跑了一小段路。

Lichtman: Surprising because it means each of these big flightless birds—the elephant bird group included—seemed to take its own winding path to flightlessness and bigness.

Lichtman：令人惊讶，因为这意味着这些不会飞的大鸟中的每一种——包括象鸟群——似乎都沿着自己蜿蜒的道路走向不会飞和变大。