The Theory of Evolution

Evolution is a gradual change over time. The theory of evolution states that:
  • life on Earth has changed over time
  • different species have gradually developed in different environments
  • these changes have occured slowly over millions of years
  • present day organisms evolved from original life through progressive changes

It is important to remember that the theory of evolution is just that - a theory. In scientific terms a theory is not just a guess or a piece of speculation. It is a collection of hypotheses that have been tested and supported consistently by available evidence. Scientific theories are concerned with what is observable, measurable and testable. Like all theories, it is constantly subject to scrutiny, re-evaluation and change.

The theory of evolution that is currently used by scientists is based on the theory proposed by Charles Darwin.

1. Seven Strips Activity - the class will be split into four groups. Each group with have some information to read on Charles Darwin. Every person in the group needs to read the information individually and write 7 sentences to summaries the most important parts. One sentence is to be written on one strip of paper.
You then join with the members of your group and combine your ideas. You group needs to come up with four sentences on 4 strips. When your group is happy one person from the group needs to edit this page and type their four sentences under the appropriate heading (below).

2. Copy the notes from this page into your own book or OneNote.

3. Comment on the discussion for this page.

Group 1 -
Youth and Education
Charles Darwin, born in Shrewsbury England in 1804, was the second youngest child in a family of eight. He studied nature as a whole and saw it as an endlessly changing display in which design and adaptation are central. Darwin met and informally met with Henslow and became a naturalist which changed the direction of Darwin’s life. His success of becoming a scientist came from his passion for observing, collecting and recording notes on the natural world, then analysing his information with excitement and enthusiasm.
Group 2 -
The Voyage of the Beagle
The HMS Beagle set sail from Plymouth in 1831, on a two year planned journey around the world aiming to improve charts of the South American coast and to fix longitude. Darwin was a naturalist and recorded observation and drew great detail on geological rock formations, fossils, flora and fauna. While exploring Galapagos Islands, he observed the variation of different finches and different adjoining islands, proving his idea of evolution. Darwin no longer found the exact word of the Bible sufficient to explain his observations; he formulated his own ideas about the development of life in Earth and therefore led to his new theory.
Group 3 -
Thoughts about a Theory
After reading a book named ‘Population’ by Malthus, a theory about evolution through natural selection came to him. In 1938 a theory came to Darwin; ‘favourable variations would tend to be preserved and unfavourable ones to be destroyed'. Darwin wrote about his theory in 1942 and discovered that Alfred Wallace had come up with the same theory 20 years earlier. Darwin’s book ‘On the Origin of Species’ was published in 1859 where 1250 copies were sold in one day.
Group 4 -
The Controversy Darwin Caused

Darwin’s important book, ‘On the Origin of Species’ offered a scientific alternative to the story of creation which was controversial and therefore was opposed by many people such as people from church and other fellow scientist.

A famous debate which occurred in June 1860 was a success for the Theory of Evolution thanks to the help of Professor Thomas Huxley and Joseph Hooker and also gained world wide acceptance from the scientific community.

After the debate, Darwin was overjoyed to have overcome the large obstacle of public opinion.

With a total of 15 books published by Darwin, his one book ‘On the Origin of Species’ made him renowned and changed what many people believed about life of Earth.