Let’s look at it another way. Let’s imagine the Earth is a hard drive, and each species on Earth, including our own, is a Microsoft Excel document on the hard drive filled with trillions of rows of data. Using our shortened timescale, where 50 million years = one month, here’s what we know:
Right now, it’s August of 2015
The hard drive (i.e. the Earth) came into existence 7.5 years ago, in early 2008
A year ago, in August of 2014, the hard drive was loaded up with Excel documents (i.e. the origin of animals). Since then, new Excel docs have been continually created and others have developed an error message and stopped opening (i.e gone extinct).
Since August 2014, the hard drive has crashed five times—i.e. extinction events—in November 2014, in December 2014, in March 2015, April 2015, and July 2015. Each time the hard drive crashed, it rebooted a few hours later, but after rebooting, about 70% of the Excel docs were no longer there. Except the March 2015 crash, which erased 95% of the documents.
Now it’s mid-August 2015, and the homo sapiens Excel doc was created about two hours ago.
Now—if you owned a hard drive with an extraordinarily important Excel doc on it, and you knew that the hard drive pretty reliably tended to crash every month or two, with the last crash happening five weeks ago—what’s the very obvious thing you’d do?
You’d copy the document onto a second hard drive.
That’s why Elon Musk wants to put a million people on Mars.