Now, you might think, well, we're human because of our DNA, but it turns out that each of us has about 20,000 human genes, depending on what you count exactly, but as many as two million to 20 million microbial genes.
你现在可能会想， 我们是人，这是由 DNA 决定的， 但是我们每个人都有 2万个人类基因， 取决于你怎么数， 但是和我们的基因相比， 微生物有 200-2000万的基因。