Directions 5/2/18 Get out your big “Natural Selection” organizer from yesterday & study them silently for 3-5 minutes HW: Study! You will have a short vocab assessment over this sheet on Friday! Quizlet flashcards are on the blog!

Who discovered the theory of Natural Selection? Charles Darwin Let’s recap how he came to “discover” this using a quick video!

Charles Darwin’s Observations- (3 min)

Finch Beaks different beak shapes are inherited variations and help birds compete for food these birds with the most “fit” beaks got the food and could survive & reproduce pass on the genes for those more “fit” beaks over time nature “selected” for different species with different beaks

From 1 species to 14 species… Warbler finch Woodpecker finch Small insectivorous tree finch Large insectivorous Vegetarian Cactus finch Sharp-beaked finch Small ground finch Medium ground finch Large ground Insect eaters Bud eater Seed eaters Cactus eater Warbler Tree finches Ground finches natural selection for best survival & reproduction variation

Relationship between species (beaks) & food

Key Vocabulary Let’s see how speciation occurs… Write this in white space above “speciation” oval A species is a group of organisms that can mate with one another to produce fertile offspring. (fertile means can have offspring too!) Speciation- the formation of new and distinct species in the course of evolution. Let’s see how speciation occurs…

How does speciation occur? 1st: Separation-part of a population splits apart (may be formation of canyon, mountain, or lakes that SEPARATES a population ) 2nd: Adaptation- organisms traits evolve (change) because they respond to different environmental conditions over time 3rd: Division- the two groups become so different they are no longer able to interbreed. (breed with each other)

Speciation- An Example In their separate niches, the groups of shrimp go their own evolutionary ways, accumulating different gene mutations, being subjected to different environmental factors, experiencing different historical events, finally becoming incapable of interbreeding should they ever come together again. The Isthmus of Panama occurred about 3 million years ago separating the Atlantic from the pacific. On one side of the isthmus appeared almost identical to those on the other side -- having once been members of the same population.  But when males and females from different sides of the isthmus are put together, they snapped aggressively instead of courting. They had become separate species, just as the theory would predict in an evolutionary process in which one species divides into two because the original homogenous population has become separated and both groups diverge from each other. 

Edhelper: How does a new species form? When finished, flip it to the front side and wait silently for teacher to collect the paper & show the “closing” video clip on speciation.

Closing: Video clip on Speciation: An Illustrated Introduction (8 min https://academy.allaboutbirds.org/speciation-an-illustrated-introduction/ YouTube…Cornell Lab Bird Academy

Speciation in Galapagos Island Finches Each student gets their own organizer and ½ pink sheet Follow directions on the sheet to complete it If you get stuck & I’ve announced all papers have been turned in, you may whisper quietly with your table partner We are doing an Edhelper first…then you will do this sheet if time!

Check your Finch Migration sequence of events: