I Feel That One Species,

It Seems To Me That For Darwin The Pulsing Of Evolutionary Rates Was A Strictly Vertical Phenomenon.

The Reduced Variability Of Small Populations Is Not Always Due To Accidental Gene Loss, But Sometimes To The Fact That The Entire Population Was Started By A Single Pair Or By A Single Fertilized Female. These 'founders' Of The Population Carried With Them Only A Very Small Proportion Of The Variability Of The Parent Population. This 'founder' Principle Sometimes Explains Even The Uniformity Of Rather Large Populations, Particularly If They Are Well Isolated And Near The Borders Of The Range Of The Species.

As A Consequence, Geneticists Described Evolution Simply As A Change In Gene Frequencies In Populations, Totally Ignoring The Fact That Evolution Consists Of The Two Simultaneous But Quite Separate Phenomena Of Adaptation And Diversification.

There Are A Number Of Attributes Of Species And Populations That Are Not Of Any Particular Selective Advantage To Any Single Individual In A Population But That Are Of Great Advantage To The Population As A Whole.

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.