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Speciation. Not as easy as it seems. Evolution creates and destroys new species. What is a species?. What is a species?. These are all one specie!. We will define a specie as:. A group of organisms that has the ability to interbreed and produce fertile offspring.
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Speciation Not as easy as it seems
What is a species? These are all one specie!
We will define a specie as: • A group of organisms that has the ability to interbreed and produce fertile offspring. • For example, these happy face spiders look different, but since they can interbreed, they are considered the same species: Theridiongrallator.
How do species arise? • Reproductive isolation of populations is key. • Geographical isolation- It occurs when populations are separated by geographic barriers such as rivers, mountains, or bodies of water. • Harris’ antelope squirrel • White-tailed antelope squirrel
Temporal Isolation • Breed at different times. • These are closely related species, but the American toad mates in the early part of summer, while the Fowler's toad mates later in the season. • Flowering plants may be temporally isolated if their flowers do not open at the same time of day. When this occurs, pollen cannot be transferred between the two different plants, so there cannot be fertilization.
Behavioral Isolation • It occurs when populations are capable of interbreeding but have differences in courtship rituals or other types of behavior.
Speciation Dynamics Phylogenic trees Darwin vs Gould