Evidence for Evolution
Biology: AQA GCSE Higher, topic 6.3.7
The Evidence for Evolution
The discovery of genes as a mechanism (way) to inherit characteristics and create variance supported the theory of evolution. In addition to this, the two main sources of evidence are:
Fossils
- Fossils show the gradual changes in organisms over vast periods of time.
Antibiotic resistant bacteria
- Natural selection neatly explains this phenomenon:
- Bacteria reproduce rapidly.
- Mutations occur during reproduction.
- If a mutated bacterium is resistant to antibiotics, it will survive exposure to antibiotics and go on to reproduce.
- This bacterium will represent the original ancestor of a new resistant strain.
Test yourself on Evidence for Evolution
Apart from genes, what are the two main sources of evidence for evolution?
Which explanation correctly describes how antibiotic resistant bacteria evolve?
A new antibiotic is introduced and one bacterium in a population has a random mutation that makes it resistant. What is most likely to happen next?
Why does antibiotic resistance spread through a bacterial population over time?
Why do fossils provide evidence for the theory of evolution?