Ask Dr. SETI: Rare Earth?

The SETI League, Inc., a membership-supported, non-profit {501(c)(3)}, educational and scientific organization Searching for Extra-Terrestrial Intelligence

Departments

Membership Services
   General Info
   Financial Info
   Activities
   Awards
   Coordinators
   Director's Info
   Members' Info
   Policies
   Forms

Publications
   Official Publications
   Director's Publications
   Ask Dr. SETI ®
   Fiction
   Non-Fiction
   Reviews
   Reading Lists

Technical Support
   Systems
   Antennas
   Amplifiers
   Receivers
   Accessories
   Hardware
   Software

Press Relations
   Fact Sheets
   Local Contacts
   Editorials
   Press Releases
   Photo Gallery
   Newsletters
   Internet Svcs

Ask Dr. SETI ®

Chapter 2: Biochemistry

Rare Earth?

Dear Dr. SETI:
What is your take on Brownlee and Ward's Rare Earth hypothesis, articulated in their book of that title?

Mark (via email)

The Doctor Responds:
Ward and Brownlee make an excellent case, Mark, that the chain of events that led to life-as-we-know-it on Earth is so highly improbable that we can rule out the possibility that it would ever be duplicated anywhere else. In other words, what we are most likely to encounter is life-as-we-don't-know-it. Thus, only in Hollywood can we expect to encounter a Star Trek universe, populated by diverse races of erect bipeds that reproduce sexually. (Of course, this in no way refutes the basic premise of SETI -- it only suggests that Grays can't exist -- they are entirely too humanoid.)