Do Frogs Come from Tadpoles? — Rethinking Origins in Development and Evolution
Do Frogs Come from Tadpoles? — Rethinking Origins in Development and Evolution
Craig Holdrege
Ghent, NY: The Nature Institute, 2017
(softcover, 87 pages)
Where does a frog come from? The answer seems obvious. It comes from a tadpole. But does it?
Surely, without the tadpole the frog does not develop. But just as surely, nowhere do we find the frog in the tadpole. The frog comes into existence only as the tadpole disappears. We need to be keenly aware of what we mean, and what we don’t mean, when we say, “A frog develops out of a tadpole” — or a tadpole out of an embryo, or an embryo out of a fertilized egg, or an adult human being out of a child.
As we will see, when we give careful attention to what is actually happening when a new phase of life develops out of a previous stage, there are large implications for our overall understanding of developmental processes. New and exciting questions arise about how we conceive of development — including that trans-species developmental process we call evolution.
TABLE OF CONTENTS
Introduction
1. Do Frogs Come From Tadpoles?
The Life of a Tadpole
Metamorphosis
Thinking Development
But What About Genes? Where Have all the Causes Gone?
Being Itself Differently
From Time to Space, From Thing to Process
2. A Biology of Beings
Portraying a Frog
Scientific Portrayal
3. Creativity, Ancestors, and Origins: What Frog Evolution Can Teach Us
The Double Nature of Life
Fossils and Life Past: Portraying or Explaining
Frog Fossil History
Forming a Picture of Evolutionary Transformation
The Problem of Ancestors
Of Origins and Creative Evolution
Acknowledgements
Notes
References