Chapter 8, Problem 1RQ

What is meant by epigenesis? How did Kaspar Friedrich Wolff’s concept of epigenesis differ from the early notion of preformation?

Summary Introduction

To define: Epigenesis.

Introduction: Epigenesis is a concept developed by German embryologist Kaspar Friedrich Wolff in 1759. It is an idea stating that the fertilized egg consists only of the building material, which gets assembled and forms the embryo’s body.

Explanation of Solution

Epigenesis states that the undifferentiated material present in the embryo will form its body. It states that undifferentiated granular material arranged in layers continues to become thinner in certain areas, to thicker in others, to segment, and to fold until the appearance of embryo’s body.

Summary Introduction

To explain: The way in which the Kaspar Friedrich Wolff’s epigenesis concept differs from preformation.

Explanation of Solution

The Kaspar Friedrich Wolff’s epigenesis states that the undifferentiated material present in the embryo will form its body. But the concept of preformation is an early belief stating that the complete body of an individual was preformed in an egg or sperm cell.