[Just another Joe]

No, No, No, he's got it entirely wrong.
It's not moving through the hydrogen clouds that cause the cosmic rays to increase thereby preventing biodiversity.

It's man, even waaaaay back when, that causes the earth to lighten or get heavier thereby causing the earth to sink or rise through the hydrogen clouds that cause the cosmic rays to increase or decrease.

We've been around a LOT longer than you think.
We keep getting killed off and coming back.

[maro]

I think I read this science fiction short story.