The founder effect describes when a small group of individuals separates from a larger group and expresses genes that were rare in the original population. If this happens, the rare gene or genes start to become common in the next generations. In contrast, the bottleneck effect happens when a random catastrophe like an earthquake kills off most of a population. In this situation, the genes in the surviving population occur randomly. The common thread that runs through both the founder effect and the bottleneck effect is that they reduce the amount of genetic diversity in a population.
Comparison Chart
| Founder Effect | Bottleneck Effect | |
|---|---|---|
| Reduces genetic diversity | Yes | Yes |
| Cause | Separation of a small group of individuals from a larger population. | The destruction of most of a population. |
| Results in a random sample of genes from the original population. | No | Yes |
| Probability of inbreeding | High | Very high |
| Can result in speciation | Yes | Yes |
| Examples |
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References
- Brennan, J. (Updated April 25, 2017). Comparison of the bottleneck effect and the founder effect. Retrieved from https://sciencing.com/comparison-bottleneck-effect-founder-effect-5188.html
- The Microevolution Debate: Bottleneck Effect vs Founder Effect. (n.d.). Retrieved December 27, 2017 from https://biologywise.com/bottleneck-effect-vs-founder-effect