1. Module 4 Intro

1.12. Page 3

Lesson 2

Module 4—Mechanisms of Population Change

Watch and Listen

 

This photo of a coral reef shows hundreds of brightly coloured fish and other reef dwellers.

© Elisei Shafer/shutterstock

A lecture from the Howard Hughes Medical Institute, titled “Endless Forms Most Beautiful,” discusses Darwin’s life (his father worried he wouldn’t have a respectable profession) and how he developed his theory of evolution by natural selection. It is a lecture for high school students. The lecture reviews mutations, variations, and how natural selection works. The lecture is about an hour long and is very informative and interesting. You may prefer to watch this at two separate times.

 

In order to find this video, you need to do a web search. It is easy to find if you type in the keywords “endless forms most beautiful evolution lecture.” Scroll down the page about halfway to find the link for the video lecture. In your web search you may also find summaries of the book titled “Endless Forms Most Beautiful,” written by the lecturer Dr. Sean Carroll. Reading these summaries may also help you understand the lecture.

 

This lecture is an excellent summary of much of what you will learn about Charles Darwin and his theories.

 

Self-Check

 

S4. Complete this Self-Check exercise after you have accessed the “Endless Forms Most Beautiful” lecture. Even if you did not explore this lecture in great depth, you will be able to answer some of the questions in this Self-Check based on your readings so far.

 

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The following animation reviews Darwin’s theory of evolution and natural selection. Watch “Darwin’s Theory of Evolution and Natural Selection” to discover the theory behind evolution by natural selection.

 

Read

 

In the same year Charles Darwin was born, Jean-Baptiste Lamarck published his theory about how species change over time. Lamarck compared fossils with current species and noticed a progression of changes from the fossil structures to the current species. He believed that species have been increasing in complexity over time in order to achieve a level of perfection. Lamarck proposed that organisms could pass on developed characteristics (for example, big muscles from working out) by the inheritance of acquired characteristics.

 

inheritance of acquired characteristics: the theory that characteristics acquired during an organism’s lifetime could be passed to its offspring

 


 

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Comparing Theories

 

Watch this animated presentation that compares the theories of evolution by Lamarck and Darwin. Make note of the similarities and differences between these theories.