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Unformatted text preview: To start our investigation, we need to go where our data are collected…. GALAPAGOS ISLANDS GALAPAGOS ISLANDS Galapagos Research Expedition Galapagos Research Expedition Galapagos Islands Galapagos Islands - islands of volcanic origin - Province of Ecuador, 500 miles west of Ecuador - at the equator Galapagos Islands Galapagos Islands
–As equatorial as it gets –“Tropical Islands” What does this mean? What climate do you expect on these islands? Galapagos Islands & Finches Galapagos Islands & Finches
–75oF for most of the year •Warmer days •Cooler nights –Rainy season and Dry season –What factors determine the climate? Climate Climate • Tropics (23.5° North and South latitude) – Tropics of Cancer and Capricorn
– Sun directly over the area at least once a year (twice in this case) = equinox • Sun’s angle to Earth defines Equinox and • So tropics have:
• • •
sun farthest away from equator, above a Tropic line) Solstice (Equinox: sun above equator, day&night equal; Solstice: High incident light Regular pattern of light (days & nights almost equal all year) Direct angle of light (more solar radiation per unit area) Climate Climate
• What else influences temperature and climate?
– Moderating effect of water – Wind – Elevation, topography – Vegetation and ground cover • Seasonality: rainy / dry seasons A unique place with unique A unique place with unique endemic species http://photo.gouldhome.com Galapagos Islands & Finches Galapagos Islands & Finches
–Can't be seen from the mainland –Geologically young volcanic –Many endemic species Some of the Animals Some of the Animals The Fauna The Fauna
– Darwin’s Finches, Galapagos Martins, Blue footed & Masked Boobies, Owls, Egrets, Gulls, Herons, Pelicans, and Frigatebirds – Marine & Land Iguanas, Sea Turtles, and Lava Lizards – Two species of rice rat, Two species of bat, Galapagos Sea Lion, and Fur Seal • Reptiles • Mammals Galapagos Birds Galapagos Birds Birds Birds Galapagos Islands & Finches Galapagos Islands & Finches • Not strong enough to fly from island to island • • • • Darwin’s Finches Darwin’s Finches Eat seeds and bugs Eaten by owls Natural selection Evolution – However • Owls can fly from islands • Finches can be blown by storms with high winds between islands So what’s the big deal? So what’s the big deal?
• One season
– Mysteriously, many finches died • No physical signs of being eaten • Always appeared to die in the morning – I need you to find out! – Don’t forget you are working with the Grants and have access to all their data • So what happened? Answer these 2 Questions Answer these 2 Questions
• Why did so many finches die in one year? • Why did some finches survive? • Come up with at least 2 hypotheses to explain each question and refute or support your hypotheses with the data the Grants have gathered for you. Let’s just study the finches! Let’s just study the finches!
• We’ll start by joining up with Peter and Rosemary Grant in the year 1973
– British scientists from Princeton – Spent 6 months out of every year on Isla Daphne major for 20 years – Caught, banded, and observed at least 25 generations of finches on the island which is an estimated 19,000 birds – Have published mounds of literature regarding evolution and natural selection affecting the Isla Daphne major finch population Finch Project Finch Project
• Data collected by Drs. Rosemary and Peter Grant – 1973 – 1978 • 1977 3/4ths of finch population died
Mediumground Finch (Geospiza fortis) Galapagos Islands & Finches Galapagos Islands & Finches
–Peter & Rosemary Grant
•yearly trips •know life tables •not an easy place to research – You are going to pretend that you are their colleagues Isla Daphne Major, The Island Isla Daphne Major, The Island
• Located in the • • • •
Galapagos near Santa Cruz Completely volcanic Very few trees Restricted access to very few visitors Tropical climate
– About 75o for most of the year • Rainy and dry seasons Galapagos Islands & Finches Galapagos Islands & Finches
–Finches aren't strong enough to fly from island to island, but owls are –One season, a bunch of finches died
•Always in the morning •No signs of having been eaten – Finches eat seeds and some bugs – Owls are their main predators on Daphne Major Galapagos Islands & Finches Galapagos Islands & Finches References References
•http://alumni.nd.edu/travel/GalapagosIslands.html •http://www.galapagos.org/ •http://www.discovergalapagos.com/ •http://www.rit.edu/~rhrsbi/GalapagosPages/DarwinFinch.html Questions for the Finch Data Questions for the Finch Data
1. Why did the finches die? 1. Why did some finches survive?
Come up with hypotheses – at least 2 for each question along with a graph that corresponds to each hypothesis. = 4 hypotheses & 4 graphs MINIMUM What data do you need to test your hypothesis? Questions for the Finch Data Questions for the Finch Data
• Are there alternate hypotheses? BRAINSTORM BRAINSTORM Hypotheses for Question 1
• – What killed the finches? • List as many possible answers as you can. HYPOTHESES HYPOTHESES
• Are any untestable? • Must be able to evaluate with empirical data. Data Data
• Empirical data:
– “Information derived from measurements made in "real life" situations “ (
http://www.nechakowhitesturgeon.org/sturgeon/glossary/index.php) – “Verifiable or provable by means of observation or experiment” (
http://www.thefreedictionary.com/empirical) – “observable by the senses” (http://
en.wikipedia.org/wiki/Empirical) Hypotheses Hypotheses
• Do we have data available for every • •
hypothesis? Start the finch program and check. If the data are not available, what would you need? How would you get it to test your hypothesis in the future? Hypotheses Hypotheses
• Which hypotheses are reasonable to test • •
and have data available? Predict: What will the graph look like if your hypothesis is true? … false? Gather the data and graph. ...
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This note was uploaded on 02/24/2011 for the course BIO 102 taught by Professor Clardy during the Spring '11 term at South Carolina.
- Spring '11