And a new study suggests that a mutation in one key gene had something to do with it.

一项新研究发现，一个关键基因的突变与此有关。

Now, what are the key design genes?

现在，关键的设计基因是什么？

What the researchers found is that a key mitochondrial gene was missing from the fungal partner in 10 of the lichen species they examined.

研究人员发现，在他们检测的地衣中，有10种地衣的真菌伙伴缺失了关键线粒体基因。

So far, the key gene in brown eyes has been discovered, but experts have had no luck so far uncovering the gene for green eyes.

到目前为止，棕色眼睛的关键基因已经被发现，但到目前为止，专家们还没有足够的运气发现绿色眼睛的基因。