Finch Beaks Finch Beaks and and

Natural SelectionNatural Selection

By: Johnny B. GoodeBy: Johnny B. Goode

Warbler Finch

Darwin and FinchesDarwin and Finches

• When Darwin explored the Galapagos Islands, When Darwin explored the Galapagos Islands, he noticed many different types of finches on he noticed many different types of finches on the different islandsthe different islands

• He came up with the idea that they came He came up with the idea that they came from the same ancestor and became new from the same ancestor and became new species through natural selection.species through natural selection.

• Each island had different finches from the Each island had different finches from the othersothers

Warbler Finch

The Finches of the GalapagosThe Finches of the Galapagos

Woodpecker Finch

Experiments in the GalapagosExperiments in the Galapagos

• 1973 – Peter and Rosemary 1973 – Peter and Rosemary Grant begin studies on Grant begin studies on natural selection and natural selection and finches in the Galapagos finches in the Galapagos islands, specifically Daphne islands, specifically Daphne IslandIsland

• 1977 – wet season did not 1977 – wet season did not occur, resulting in huge occur, resulting in huge droughtdrought– More than 1,000 finches diedMore than 1,000 finches died

Medium Ground Finch (G.fortis)

Experiments in the GalapagosExperiments in the Galapagos

• After drought, there were more big After drought, there were more big G.fortisG.fortis finches than small onesfinches than small ones

• Big finches can eat bigger seeds that small Big finches can eat bigger seeds that small finches can’tfinches can’t– Being more flexible with type of food allowed the Being more flexible with type of food allowed the

big finches to survive after the small finches ran big finches to survive after the small finches ran out of foodout of food

Medium Ground Finch (G.fortis)

Result of Drought on Finch Beak SizeResult of Drought on Finch Beak Size

Small Tree Finch

Genetics and Finch Beak SizeGenetics and Finch Beak Size

• Before the drought, there was a wide variety Before the drought, there was a wide variety of beak sizes in of beak sizes in G.fortisG.fortis, including big beaks., including big beaks.

• After the drought, there were more big-After the drought, there were more big-beaked finches left, and they reproduced to beaked finches left, and they reproduced to create a generation of big-beaked finches.create a generation of big-beaked finches.

• The finches with big beaks had genes that The finches with big beaks had genes that made them have big beaks and then their made them have big beaks and then their offspring had big beaks, too.offspring had big beaks, too.

Vegetarian Finch

ReferencesReferences• Background photo:Background photo:

– Allen, S. (n.d.). Allen, S. (n.d.). Birds of the Galapagos Islands & South AmericaBirds of the Galapagos Islands & South America . Retrieved October 04, 2009, from Steve Allen Travel . Retrieved October 04, 2009, from Steve Allen Travel & Wildlife Stock Photography: & Wildlife Stock Photography: http://www.steveallenphotography.com/64.htmlhttp://www.steveallenphotography.com/64.html

• Background soundsBackground sounds– Medium Ground Finch: Medium Ground Finch:

http://www.xeno-canto.org/sounds/uploaded/DABODLPUPA/Medium_Ground-Finch_Floreana1_7-28-08.mp3http://www.xeno-canto.org/sounds/uploaded/DABODLPUPA/Medium_Ground-Finch_Floreana1_7-28-08.mp3– Small Tree Finch: Small Tree Finch: http://www.xeno-canto.org/sounds/uploaded/DABODLPUPA/Small_Tree-Finch_7-28-08.mp3http://www.xeno-canto.org/sounds/uploaded/DABODLPUPA/Small_Tree-Finch_7-28-08.mp3– Vegetarian Finch:Vegetarian Finch:

http://www.xeno-canto.org/sounds/uploaded/XTVEPHMPPJ/Platyspiza_crassirostris_1979_02_22.mp3– Warbler Finch: Warbler Finch: http://www.xeno-canto.org/sounds/uploaded/DABODLPUPA/Warbler_Finch1_7-26-08.mp3http://www.xeno-canto.org/sounds/uploaded/DABODLPUPA/Warbler_Finch1_7-26-08.mp3– Woodpecker finch: Woodpecker finch:

http://www.xeno-canto.org/sounds/uploaded/XTVEPHMPPJ/Camarhynchus_pallidus_1979_02_22.mp3

• Darwin and FinchesDarwin and Finches– Zimmer, C. (2006). Zimmer, C. (2006). Evolution: The Triumph of an Idea.Evolution: The Triumph of an Idea. New York: Harper Perennial. New York: Harper Perennial.

• Finches of the GalapagosFinches of the Galapagos– http://biology.unm.edu/ccouncil/Biology_112/Images/FinchTypes.jpg

• ExperimentsExperiments in the Galapagosin the Galapagos– Zimmer, C. (2006). Zimmer, C. (2006). Evolution: The Triumph of an Idea.Evolution: The Triumph of an Idea. New York: Harper Perennial. New York: Harper Perennial.– Image: Image: Explore EvolutionExplore Evolution. (n.d.). Retrieved October 04, 2009, from University of Nebraska State Museum: . (n.d.). Retrieved October 04, 2009, from University of Nebraska State Museum:

http://explore-evolution.unl.edu/grant.html

• Result of Drought on Finch Beak SizeResult of Drought on Finch Beak Size– Morris, T. (n.d.). Morris, T. (n.d.). Ecological Genetics: Adaptation and Natural SelectionEcological Genetics: Adaptation and Natural Selection . Retrieved October 04, 2009, from Ecological . Retrieved October 04, 2009, from Ecological

Genetics:Adaptation and Natural Selection: Genetics:Adaptation and Natural Selection: http://staffwww.fullcoll.edu/tmorris/elements_of_ecology/chapter_5.htm