Invented Only Once?

In Ayn Rand's novel The Fountainhead, there's a scene where villain Ellsworth Toohey looks at the New York City skyline and muses about modern civilization:

...Look at it. A sublime achievement, isn't it? A heroic achievement. Think of the thousands who worked to create this and of the millions who profit by it. And it is said that but for the spirit of a dozen men, here and there down the ages, but for a dozen men -- less, perhaps -- none of this would have been possible. And that might be true.

(Part 2, Chapter 8)

When I first read that passage, I wasn't sure whether it was historically accurate or not.

But as it turns out, there a number of crucial innovations that some claim to have only been invented and/or discovered once in history, then spread to the rest of humanity from that single source.

I can't vouch for the accuracy of all of the following, but some purported examples include:

The wheel

The alphabet

Dog domestication

Iron smelting

And probably the most crucial to Western civilization:

Logic (Aristotle)

If these claims are true, then it may indeed be the case that our modern technological society (including my ability to compose this blog post on a MacBook Pro and upload it onto a remote web server where it can then be read by people around the world) would not exist were it not for a half-dozen mostly-anonymous innovators.