Evolution by Natural Selection
Darwin
'Darwin was a British scientist who laid the foundations of the theory of evolution and transformed the way we think about the natural world.' - BBC
Charles Darwin was from not too far from us. You can find out more about him here:
'Darwin was a British scientist who laid the foundations of the theory of evolution and transformed the way we think about the natural world.' - BBC
Charles Darwin was from not too far from us. You can find out more about him here:
What is a theory?
The word theory has different meanings depending when you use it. In science it means this:
'A scientific theory summarises a hypothesis or group of hypotheses that have been supported with repeated testing. If enough evidence accumulates to support a hypothesis, it moves to the next step—known as a theory' - Livescience
'A scientific theory summarises a hypothesis or group of hypotheses that have been supported with repeated testing. If enough evidence accumulates to support a hypothesis, it moves to the next step—known as a theory' - Livescience
In short:
Natural selection
The theory of evolution states that evolution happens by natural selection. The key points are that:
Individuals that are poorly adapted to their environment are less likely to survive and reproduce. This means that their genes are less likely to be passed to the next generation. Given enough time, a species will gradually evolve.
You need to remember that variation can be caused by both genes and the environment. But it is only variation caused by genes that can be passed on to the next generation.
Adapted from BBC Bitesize
Natural selection
The theory of evolution states that evolution happens by natural selection. The key points are that:
- individuals in a species show a wide range of variation
- this variation is because of differences in their genes
- all species have more young than can survive. This results in a struggle to survive - all organisms must compete
- individuals with characteristics most suited to the environment (favourable adaptations) are more likely to survive and reproduce
- the genes that allow these individuals to be successful are passed to their offspring
Individuals that are poorly adapted to their environment are less likely to survive and reproduce. This means that their genes are less likely to be passed to the next generation. Given enough time, a species will gradually evolve.
You need to remember that variation can be caused by both genes and the environment. But it is only variation caused by genes that can be passed on to the next generation.
Adapted from BBC Bitesize
This button will take you to a brilliant documentary about the evolution of life on Earth