161 



Figure 1 . A schematic representation illustrating what can happen to the genetic diversity of a 

 salmon run over time as a result of genetic bottienecks. The letters represent different genetic 

 characteristics. The resulting fragmented populations a ppear to have different ancestries. Bot- 

 tlenecks are severe population reductions caused by human induced and/or natural changes such 

 as habitat destruction. (Adapted from O'Brien and Evermann (1988). 



200 Years Ago 

 ABCDEFGHIJ KLMNOP 



Bottleneck 



Bottleneck 



Bottleneck 



Extinction 

 Adapted from TBEE Vol.3. Nc.10. October 1988 



9 



