The Origin of Trait Diversity

1) Organisms replicate in surplus 2) Environment favors replicates with altered traits that convey replication advantage3) This is called Natural Selection

which over long time periods become small differences become big differences gradually allowing organisms to turn into different organisms

Charles Darwin

Darwin did not explain thebasis of variation: He used

pangenic transmutation

Vague concepts

Because pangenesis and transmutation had no tangible

(observable) evidence of support,Darwin’s theory was not complete

Restated - Important1) Organisms beget organisms (not always with perfect

fidelity)BUT WHY?

Because whatever is the basis of traits also does not replicate with perfect fidelity.

BUT WHAT and WHY?

Inheritance (the begetting) of traits occurs in discrete units that follow a clear pattern (sort of)7 strong (qualitative) traits on

different chromosomes But still no good explanation for

origin or basis of variation in units

TAKE HEART!Impact factor for 35 years 0.01

Gregor Mendal

THE MISSEDOPPORTUNITY

THE QUANTITATIVE

TRAITS

This was a key point that led to a biased (or more appropriate –confused) understanding of the basis of genetics (coined by Bateson) (Mendel did not know what inheritance units are) and led to a great dispute that echoes still today

Bateson

THE DEBATE:

(A) Natural Selection works by favoring very small trait changes accumulating over long time periods

The biometrics peopleWeldon

A big argument by TWO camps Bateson, etc. on one side Mendalism/qualitativeWeldon, etc. on the other Gradualism/quantitative

Fisher Pearson

OR (B):Natural selection works by big trait

changes in punctuated leaps (promoted by Bateson’s view of Mendelism – opposed by Weldon)

Morgan’s work with fruit flies established clearly that big trait changes occur. Statistics are not needed to tell red eyes from white eyes! (it took 2 years to find white eye) advanced many ideas including genes are ordered and can be mapped

Also, Morgan greatly diminished the view of acquired inheritance, although Morgan himself struggled with these concepts early in his career (more later)

T.H. Morgan

Did you know that our government is wasting money on silly research

on fruit flies?

John, calm down, science is Good. I’m sure fruit fly

science is also good.

» Director, Lawrence Berkeley National Lab» Professor of Physics, Professor of Molecular and Cell Biology at UC Berkeley» Stanford University, 1987-2004» AT&T Bell Labs, 1978-1987» Ph.D. in physics, University of California, Berkeley, 1976.» 1997 Nobel Prize in physics

STEVEN CHU, 60

Yes, Mr. President, all science IS good, especially when done by scientists!