Now, that's one argument and we have to be humble in the face of uncertainty here.

No one knows, but I want to give an argument that rarely gets any air time.

The argument is that we are alone and the argument has nothing to do with astronomy.

It has everything to do with biology.

The argument goes like this.

Look at planet Earth and look at the number of species not only that exist right now,

millions of them, but the number of species that have ever existed on planet Earth, hundreds

and millions.

When life arose, something like 3.5 billion years ago, for about 2.5 billion years, for most

of the history of life on Earth, there was nothing but bacteria.

So life apparently doesn't have much impetus to evolve quickly beyond bacteria.

It just remains as simple as possible.

A lot of people have this misconceived idea that Darwin really did it way with.

The idea that evolution has a direction in mind.

You see these pictures of evolution that appear in high school textbooks of the monkey that's

hobbling around and all fours and he's hunched over and then eventually he's standing up

and holding a briefcase.

As if this is what evolution had in mind, it only seems to be what evolution had in mind

in retrospect by looking backwards.

This American academic is named Charlie Loneweaver and he calls this the planet of the

apes hypothesis as if if you removed the humans from a planet, the apes would naturally evolve

to fill the intelligence niche.

...