1. Natural Selection in Action: Tadpoles vs. Crayfish

2. Invasive Species What is an invasive species? –A species that is non-native to the ecosystem (not originally found there) –Presence is likely to cause environmental or economic harm –Can be plants, animals, microbes –Usually introduced to an area by humans (on purpose and accidentally)

3. Invasive Species Examples: Arundo donax – giant reed –Found in riparian (stream) habitats –Invasive in southern California –Displaces native plants and provides poor habitat for insects and wildlife –Fire and flood hazard

4. Invasive Species Examples: Argentine Ant (Linepithema humile) –Native to Argentina, invasive worldwide, also in southern CA (these are the ants you see in your house) –Displaces native ants or causes local extinctions –In southern CA, responsible for decline of native ants which are sole food source of CA horned lizard

5. Invasive Species Examples: Zebra mussel (Dreissena polymorpha) Native to Russia, introduced worldwide Change natural food webs Huge economic impact – clog pipes, cover boats

6. Invader: Red swamp crayfish (Procambarus clarkii ) Invasive in southern California streams Introduced by humans worldwide for aquaculture (eating), accidentally as bait or with fish stock Will eat almost anything, including amphibians (eggs, tadpoles)

7. Crayfish have invaded the Santa Monica Mountains

8. Prey: Pacific treefrog tadpoles (Pseudacris regilla) Native range from Mexico to British Columbia, Pacific coast to Montana, Nevada Found in streams with and without crayfish in the Santa Monica Mountains but show reduced abundance in the presence of crayfish

9. Predator Escape What traits might help a tadpole escape from a crayfish?

10. My Research Predation is a strong form of natural selection Are crayfish causing tadpoles to evolve? McCollum and Leimberger 1997

11. My Research I am examining tadpoles from streams with and without crayfish and looking at anti-predator traits I will compare morphology, behavior, and ability to survive with crayfish

12. My Research Tadpoles from streams with crayfish may show these adaptations: –Longer tails or bigger tail muscles –Behavioral response of hiding and swimming less when crayfish are present –Increased survival in the presence of crayfish

13. Credits Slide 1 : http://www.freewebs.com/siganurme/seapea.htm and http://giraffian.com/pictionary- files/t/tadpole.pnghttp://www.freewebs.com/siganurme/seapea.htmhttp://giraffian.com/pictionary- files/t/tadpole.png Slide 3: http://thegreencuttingboard.blogspot.com/Arundo-donax.jpg and http://members.tripod.com/~Hatch_L/arundodonaxvar.jpghttp://thegreencuttingboard.blogspot.com/Arundo-donax.jpg http://members.tripod.com/~Hatch_L/arundodonaxvar.jpg Slide 4: http://www.issg.org/database/species/ecology.asp?si=127&fr=1&sts=&lang=EN and http://news.illinois.edu/WebsandThumbs/Suarez,Andrew/argentine_ants_b.jpg and http://i.livescience.com/images/060914_ant_fight_02.jpghttp://www.issg.org/database/species/ecology.asp?si=127&fr=1&sts=&lang=EN http://news.illinois.edu/WebsandThumbs/Suarez,Andrew/argentine_ants_b.jpg http://i.livescience.com/images/060914_ant_fight_02.jpg Slide 5: http://www.issg.org/database/species/ecology.asp?si=50&fr=1&sts=&lang=EN and http://conservationreport.files.wordpress.com/2008/11/zebra-mussel-not-wanted-poster.jpg and http://upload.wikimedia.org/wikipedia/commons/0/0b/Zebra_mussel_GLERL_3.jpghttp://www.issg.org/database/species/ecology.asp?si=50&fr=1&sts=&lang=EN http://conservationreport.files.wordpress.com/2008/11/zebra-mussel-not-wanted-poster.jpg http://upload.wikimedia.org/wikipedia/commons/0/0b/Zebra_mussel_GLERL_3.jpg Slide 6: http://nas.er.usgs.gov/taxgroup/Crustaceans/maps/pr_clarkii.gif andhttp://natural- japan.net/photos/Procambarus_clarkii_04.jpghttp://nas.er.usgs.gov/taxgroup/Crustaceans/maps/pr_clarkii.gifhttp://natural- japan.net/photos/Procambarus_clarkii_04.jpg Slide 7: Images from Katherine Pease Slide 8: http://www.iucnredlist.org/details/55897/0 and images from Katherine Peasehttp://www.iucnredlist.org/details/55897/0 Slides 9 and 11: Images from Katherine Pease Slide 10: Image from McCollum and Leimberger (1997) Oecologia Slide 12: http://www.mister-toad.com/PacificTreeFrog.htmlhttp://www.mister-toad.com/PacificTreeFrog.html