Problem
• Why are there more non-native or invasive plants close to the walking path? Why might this be a problem for native species? In the transport of nonnative species, humans are the actors in what evolutionary process?
Finches decline
• In 1997 researchers noticed dying finches, what is wrong with the baby finches?
• How does the parasite cause harm?
• What is the percent mortality of the birds?
• How many species are facing extinction?
• The story mentioned that with the mangrove finch there are only 60-80 individuals left? Why is this troublesome for this population of finches?
• How are the researchers trying to control the flies?
• How might the finches be adapting to the presence of the flies?
Hybrid Finches
• How are the three species of finches on Floreana island kept isolated? (Hint: think of the barriers to gene flow)
• The three species of finches have since started interbreeding and there are now hybrid species. What if any advantages do the hybrid finches have?
Conclusion
• The episode ends with the statement "...in the story of these finches is the story of the Galapagos". How do you interpret this statement?