Isolation is a factor in the evolution of a new species from an existing species. An interesting case of isolation involves changes in migration patterns for some of the Blackcap (Sylvia atricapilla) which have changed their migration pattern. Observations of this group show some signs of natural selection occurring and possibly even the formation of a new species.
Listen to Birdfeeder speciation, the interview with Dr. Keith Hobson on the CBC radio show Quirks and Quarks, then answer the following questions:
- What observation have been made that suggest that natural selection is occurring?
- What are different ways a group can be reproductively isolated from the main population? (Check in the textbook or other resource)
- How is the group that migrates to Britain becoming reproductively isolated?
- Is there justification in saying that the group that over-winters in Britain is a new species?
Birdfeeder speciation (Quirks and Quarks interview)
