In the Adaptation Lab we showed how the finches of the Galapagos Islands slowly adapted to the food that was available to them on different islands. When the finches arrived on a new island, they developed adaptations over time to help them survive on that island.
1. An adaptation is _________.
When a group of finches separates from their old island, they have to adapt to their new island. Since there was reproductive isolation between the finches on the new island and the old group they came from, the finches on the new island slowly, over time, began to look different from the old finches. Eventually the finches on the old island and the finches on the new island will have different beaks. These different beaks are adapted to eat the foods they found on the island they lived on.
2.This explains the process of __________, which is defined as the formation of new species as a result of evolution.
Announcements & Upcoming Dates!
-Ch 17 Study Guide & notebook work time on Thursday
-Ch 17 Test & notebook check on Monday, 12/5
Return papers
Review Bird Beak Lab Questions & Conclusions; glue lab into notebook
Galapagos Finches Video (16 mins)
Begin new right hand page in notebook (handout here)
Heading: Speciation 11/29/16
Learning Objective: I can explain how a species is defined and how new species are formed.
-Scientists may define a species based on physical features, ecological roles, or genetic similarities.
divergence - an increasing number of differences between populations; can lead to speciation
-Speciation rarely happens quickly. It happens in stages over many generations.
-A new species has formed when:
-the population has unique traits
-the population is reproductively isolated
subspecies - a population that has diverged in some way from other populations of the same species; can eventually become separate species if they become unable to interbreed and produce fertile offspring.
Populations can become reproductively isolated by:
-geography (location)
-ecological niche (‘job’ in an ecosystem)
-mating behavior & timing of mating
-polyploidy (genetic differences)
-hybridization (mix of 2 species that may form a new species)
Watch 'Speciation: Of Ligers & Men' Crash Course Video (10:24 mins)
Answer these questions as you watch
1.What is a species?
2.What are two examples of animals that are a result of two different species reproducing?
3. When a species separates because of a geographic barrier it is knows as ________ speciation.
4. Dog breeding is an example of ________ selection.
