Speciation and Adaptive Radiation Speciation l Speciation is

Speciation l Speciation is a name given to theoretical process of creating a new

Niche l Niche is the word used to describe the combination of an organism’s

Speciation Example l According to the fossil record, Dinosaurs were the dominant species during

Reproductive Isolation Segregation of a population of species that DO NOT interbreed l Need

l If two populations become dissimilar in body structure and behavior, particularly mating behavior,

Darwin’s Finches-Speciation l l l STEP 1: FOUNDING FATHERS AND MOTHERS STEP 2: SEPERATION

Another example l There are many different species of Galapagos Tortoises alive today (and

l Under what circumstances can two species coexist successfully? l What will happen if

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Speciation and Adaptive Radiation

Speciation l Speciation is a name given to theoretical process of creating a new species from pre-existing species of organism through modes of natural selection. l Can not be done by means of artificial selection of different existing species.

Niche l Niche is the word used to describe the combination of an organism’s “profession” and the place where it lives. l No species can occupy the same niche Due to COMPETITION l Species that fill an unoccupied niche do so by adaptation This CREATES ENTIRELY NEW SPECIES

Speciation Example l According to the fossil record, Dinosaurs were the dominant species during the Mesozoic era and mammals were very few and far between. l But around the time when the dinosaurs died out, new mammal species seemed to appear from nowhere…likely due to speciation and newly opened niches.

Adaptive Radiation

Reproductive Isolation Segregation of a population of species that DO NOT interbreed l Need Physical/ Behavioral Barriers. l If not isolated Blending of genes No New Specie l

l If two populations become dissimilar in body structure and behavior, particularly mating behavior, what do you think will happen to them? • Decreased chance of breeding… This is called Behavioral Isolation

Darwin’s Finches-Speciation l l l STEP 1: FOUNDING FATHERS AND MOTHERS STEP 2: SEPERATION OF POPULATIONS STEP 3: CHANGES IN THE GENE POOL STEP 4: REPRODUCTIVE ISOLATION STEP 5: SHARING THE ISLAND

Darwin’s Finches

Another example l There are many different species of Galapagos Tortoises alive today (and many extinct). Each seems to have been derived by speciation from a common single ancestor species.

l Under what circumstances can two species coexist successfully? l What will happen if the niches of two species are too similar? l How might further evolution occur?