Plural into Singular

Some things can be both singular and plural. My brain is singular, but my brains are inside my skull. Except for number, the terms are pretty much interchangeable.

Here’s an unrelated of something being plural, but we treat it as singular.

From the ages and sizes of animals, archaeologists can deduce the populations of herds in terms of age and sex ratios, all of which reveals how herding differed from hunting.

https://aeon.co/essays/revolutionary-archaeology-reveals-the-deepest-possible-anthropocene

Okay, we have lots of plurals here: ages and sizes, archaeologists, populations, herds, age and sex ratios. But we have a singular verb, reveals! Why? Because they got combined into a single group, all.

American English does this a lot. “Team” is singular, and other collective nouns. The British don’t. (Hmm. Here I have an apparently singular word, “British,” but it’s a plural.) I feel sorry for people who have to learn English.

Sorry, I don’t have a good picture to go with this lesson. How do you picture something that’s simultaneously singular and plural?

All that said, I found a goof in the same article:

The increasingly sophisticated use and analysis of ancient DNA now allows researchers to track the development and distribution of domesticated animals and crops in great detail.

In this case we have a compound subject, which counts as a plural, even if the elements of the compound are singular. So they should have a plural verb, “allow,” not “allows.” Harrumpf.