Scientific Progress Consists In The

Every Politician, Clergyman, Educator, Or Physician, In Short, Anyone Dealing With Human Individuals, Is Bound To Make Grave Mistakes If He Ignores These Two Great Truths Of Population Zoology: (1) No Two Individuals Are Alike, And (2) Both Environment And Genetic Endowment Make A Contribution To Nearly Every Trait.

A Species Consists Of A Group Of Populations Which Replace Each Other Geographically Or Ecologically And Of Which The Neighboring Ones Integrate Or Hybridise Wherever They Are In Contact Or Which Are Potentially Capable Of Doing So (with One Or More Of The Populations) In Those Cases Where Contact Is Prevented By Geographical Or Ecological Barriers.

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

Anyone Who Writes About "darwin's Theory Of Evolutionin The Singular, Without Segregating The Theories Of Gradual Evolution, Common Descent, Speciation, And The Mechanism Of Natural Selection, Will Be Quite Unable To Discuss The Subject Competently.

I Had Found Again And Again That The Most Aberrant Population Of A Species - Often Having Reached Species Rank, And Occasionally Classified Even As A Separate Genus - Occurred At A Peripheral Location, Indeed Usually At The Most Isolated Peripheral Location.