Everything is inspired by something.
There are no unique ideas. Protoype an JQuery pretty much try and solve the same problem which is how you make JavaScript pleasant to use. And they both try and make it simpler to do mundane and often times complex things with less typing. Of course, they do much more than that we well.
The largest difference I see between Prototype and Ajax is Prototype feels more like an Object Oriented approach where JQuery feels more like an expression language. Consider this...
Prototype
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new Ajax.Updater(...)
JQuery
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$.load(...)
Both do the exact same thing, more or less. They take the response from an AJAX request and shove it on the page.