Our Understanding Of The World Is Achieved

Paleontologists Had Long Been Aware Of A Seeming Contradiction Between Darwin's Postulate Of Gradualism, Confirmed By The Work Of Population Genetics, And The Actual Findings Of Paleontology. Following Phyletic Lines Through Time Seemed To Reveal Only Minimal Gradual Changes But No Clear Evidence For Any Change Of A Species Into A Different Genus Or For The Gradual Origin Of An Evolutionary Novelty. Anything Truly Novel Always Seemed To Appear Quite Abruptly In The Fossil Record.

The Issue, As Correctly Emphasized By Carl Sagan, Is The Probability Of The Evolution Of High Intelligence And An Electronic Civilization On An Inhabited World. Once We Have Life (and Almost Surely It Will Be Very Different From Life On Earth), What Is The Probability Of Its Developing A Lineage With High Intelligence? On Earth, Among Millions Of Lineages Of Organisms And Perhaps 50 Billion Speciation Events, Only One Led To High Intelligence; This Makes Me Believe In Its Utter Improbability.

It Is Curious How Often Erroneous Theories Have Had A Beneficial Effect For Particular Branches Of Science.

Evolution Thus Is Merely Contingent On Certain Processes Articulated By Darwin: Variation And Selection.

All Interpretations Made By A Scientist Are Hypotheses, And All Hypotheses Are Tentative. They Must Forever Be Tested And They Must Be Revised If Found To Be Unsatisfactory. Hence, A Change Of Mind In A Scientist, And Particularly In A Great Scientist, Is Not Only Not A Sign Of Weakness But Rather Evidence For Continuing Attention To The Respective Problem And An Ability To Test The Hypothesis Again And Again.