Geology 105 - Paleontology
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Ontogeny

Reading: Chapter 2, p. 21-30

We will use all of this material.

Background

Terms:

Key Concepts and Questions:

1. How does an organism change over its lifetime?

A. Find definitions and an example for each of the four patterns of growth:

Growth pattern	Definition	Example
accretion
addition
molting
modification

B. How does an organism's growth pattern affect the information we can get from the fossil record about that organism? (You can start this from the book and we'll finish it in class.)

Growth pattern	How is information affected?
accretion
addition
molting
modification

C. Rates of Growth

1. What is the difference between allometric and isometric growth?

 

 

 

2. Why is allometric growth more common than isometric?

 

 

3. Why does allometric growth place limits on the maximum size of organisms?

 

 

2. How can ontogenetic changes influence evolution of a lineage?

This is a review of heterochrony.

What is heterochrony and why does it metter in evolution?

 

 

 

 

 

 

 

 

 

Assessment

1. Patterns of growth

You should be able to:

• describe and give an example of the four patterns of growth.
• explain how growth patterns affect the information we can extract from the fossil record
• given a set of paleontological data, sort out how growth patterns may influence the interpretation fo that data

2. Rates of growth

You should be able to:

• define allometric and isometric growth
• describe the consequences of isometric or allometric growth on the shape of an organism
• explain why allometric growth is more common than isometric

3. Heterochrony

You should be able to:

• define heterochrony and explain its significance in evolution