A Question about Reincarnation

[A brief excerpt from When the Stars Align.]

"If reincarnation is really true, how come there are so many more people on Earth now than there were millennia ago? Where did they all come from?"

To my mind, that's a bit like looking at Grand Central Station in New York during rush hour and asking, "How come there are so many more people around now than there were a few hours ago? Where did they all come from?"

In other words, the question assumes that Earth is the only celestial body in the cosmos where souls incarnate, or that there is a limited number of souls in existence—neither of which is likely true.

But another factor to consider is, how many souls have lived on the Earth over the last several million years or so? Do we really know for sure? Isn’t it possible that many of those who have been waiting for bodies to become available are now rushing in while the opportunity presents itself, leading to a kind of spiritual “rush hour” on the planet?