Darwin’s revolutionary evidence
1 February 2010Add to My Folder
Teach children about the importance of collecting and analysing evidence in science by exploring the work of one of most influential scientists in history
Few scientists have had a greater (or more controversial) influence over our understanding of the natural world than Charles Darwin, and few have shown such patience! Darwin voyaged around the world and collected thousands of animal specimens from different continents – then he spent more than 20 years developing his theories and gathering evidence, before finally publishing The Origin of Species in 1859.
Teaching children about Darwin helps them to appreciate that all scientists need to work diligently to collect and analyse evidence for their ideas. Our knowledge of the world is based on this evidence and our understanding changes as new evidence comes to light.
In this article…
- Darwin’s key ideas
- Evidence for Darwin’s theories
- Web links
- Related resources
- Activities for ages 7-11
Darwin’s key ideas
- There are not enough resources available for all organisms to survive, so organisms have to compete. That means that there is a ‘struggle’ between organisms to survive and reproduce.
- Organisms within a species show variation. Organisms with traits or features that give them an advantage (faster speed, better camouflage, for example) will be better able to exist and reproduce. Their characteristics will be passed on to their offspring.
- Organisms change over time and this change is gradual and achieved through a process of ‘natural selection’. Organisms with ‘weaker’ genes will die out with the ‘fittest’ surviving.
- All organisms originate from a common ancestor but have ‘branched’ over time into different families and species.
Evidence for Darwin’s theories
Darwin provided a lot of evidence for his ideas in his books, based on his observations and research. Since his death, and as genetic technology has developed, more evidence has come to light. Here are some of the key facts used as evidence for the Theory of Evolution:
- Darwin initially studied the beaks of finches in the Galapagos Islands, finding that they had evolved to suit the birds’ diet. For example, those that ate insects had longer, thinner beaks, while those that needed to crush seeds had wider, thicker beaks.
- When the fossil record is arranged in chronological (time) order it shows evidence of continual evolutionary change, with different traits becoming prominent at different stages of the timeline. There are no fossils of modern animals, which indicates that these have evolved from those in the past. Many fossils show characteristics that we can see today in modern species.
- Scientists have found evidence of evolution in action, such as the Peppered Moth. This moth evolved to be darker in colour in particular parts of the country that had a lot of industrial pollution (where the darker colour help camouflage the moth). Likewise, viruses evolve to become resistant to antidotes.
- Animals in different parts of the world have adapted to suit their habitat. For example, there are different populations of rat snake in North America, each showing adaptations to suit their local environment but still part of the same species.
- Natural selection has been artificially constructed in laboratories (and animal breeders select animals with the best traits in the hope that these will be passed to offspring).
- The anatomy of different organisms is similar. For example, there are many similarities between the skeletal structure of a human, horse and fish. This suggests a common ancestor.
- The same thing is also true at a molecular level – many organisms have similar DNA sequences which indicates a ‘tree of life’ that branched from a common ancestor. This is the reason that (controversially) medicines can be tested on animals before being deemed suitable for humans. There is also evidence that the human genome has altered over time.
- Explore the evolutionary links between living things with the Wellcome Tree of Life interactive
- Learn about natural selection and play games on the Science Channel Discovery site
Other useful websites include:
- Take a look at these exciting ideas for a Darwin theme week.
- Challenge your class to a Darwin trivia quiz.
Activities: Age range: 7-11
Curriculum links: Sc1 1a, 1b, 2a-m; Sc2 1a, 1c, 4a-c, 5b, 5c; English; history; geography; art.
- Introduce Darwin’s ideas and encourage discussion about them. The Science Channel Discovery site has a good interactive overview of natural selection.
- Invite the children to explore the evidence available for Darwin’s ideas for themselves. For example, they could look at skeletons of different species to spot similarities or look for similarities between species in different parts of the world, such as the marsupials of Australia.
- Much of the evidence for natural selection comes from the fossil record. Show the children images or actual examples of different fossils. After research, ask them to create flow diagrams showing how fossils are formed. They could look at different fossil images and place them on a timeline. They could also make their own fossil artworks by pressing natural objects (for example leaves, shells) into clay to form imprints.
- Ask the children to investigate the different strategies plants have developed to distribute their seeds. They could collect samples of different seeds and draw diagrams of the process of distribution.
- Invite the children to research a range of different environments (for example desert, ocean) and the creatures that live there. How are they suited to their environment? Pupils could make large labelled posters showing the creatures and their adaptations in the habitat.
- Give the children time to critically evaluate and review online resources about Darwin and evolution (for example the Wellcome Tree of Life interactive) in terms of layout, navigability, ease-of-use, fun, age appropriateness and educational value.
- Tell the children that grouping and classification is an important scientific skill. Give them a number of different pictures of mammals, reptiles, birds, fish, etc and ask them to discuss all the different ways that these could be grouped (for example according to whether or not they have fur, their colour, how they move or even whether they are in the first or second half of the alphabet).
- Ask the children to research evidence against the Theory of Evolution. This could be the theme of a mock debate.
- Talk about the fact that evidence can be misleading, so scientists need to gather a lot of evidence from many different sources to support their ideas. Tell the children that it is similar with their own research and that they shouldn’t rely on information from a single source. When conducting experiments, ask the children to talk about the importance of the evidence they found and how it led them to the results.
- Challenge the children to come up with their own ideas about an aspect of science and to try to find favourable evidence.
- Did Darwin ‘kill God’, as a line from Creation, the recent biopic of his life, suggested? Talk with the children about the impact Darwin’s book had on the highly religious Victorians. Ask them why they think some people loved and some hated it. Ask them to write sentences or phrases to reflect both opinions and then select one of these. The children should form two lines. Choosing a child to role play Darwin, have him or her walk between the lines as pupils whisper their message as Darwin’s ‘conscience’.