"And finally, did you know that only a miraculous set of
circumstances makes life here on Earth possible? For instance,
the planet's size is just exactly right to hold our atmosphere.
The atmosphere contains just enough oxygen to support life.
And our distance from the sun is just perfect for the right
temperature. Should there be even a trivial change in any of
these conditions, all life here on Earth would certainly be
obliterated in a matter of milliseconds. This is Les Nessman
saying good day, and may the good news be yours.
Apparently, the Harvard guy doesn't think any other planet can meet
and sustain these conditions.
Life doesn't need to evolve in the same conditions that exist on earth. We have microbes and bacteria right here that live in conditions that are deadly to animal and insect life.
Our planet is very likely to be inhospitable to life forms that have evolved on other planets.
Don’t think in such narrow terms. Life does NOT need oxygen
or even an atmosphere. Nor does all life even need moderate tempertures. Perhaps SOME life on earth does however there have been many discoveries of life even here on earth living in extreme environments