Do now activity What is the difference between single gene traits and polygenic traits? What is the gene frequency for brown hair in this classroom? True or False: In a population, there will always be more dominant traits than recessive traits. If the #3 is False, re-write it to make it a True statement.
How can a species be changed by its environment? Essential Question: How can a species be changed by its environment? Learning Target Justify why an advantageous trait will increase in proportion from one generation to another when provided statistical evidence. Use data to explain how change in gene frequency caused by natural selection is related to environmental factors such as seasonal temperature, climate change, acidity, light, geographic barriers, & evolution of other organisms. Section 7-2: speciation
Critical Readings must be stamped and turned in by tomorrow (2/8/17). announcements Biology Tutoring this week: Lunch B (Tuesday & Thursday) 7:00AM (Monday – Friday) After school Biology Tutoring: Tuesday Critical Readings must be stamped and turned in by tomorrow (2/8/17).
announcements Available Extra Credit: Tissue Box = 2 Points Starburst Original Jellybeans = 5 Points Stauffer’s Original Animal Crackers = 10 Points
Don’t forget to chunk your notes!
Fitness: having adaptations to help you survive the environment overview Fitness: having adaptations to help you survive the environment
Fitness: being able to find mates and reproduce to pass on traits overview Fitness: being able to find mates and reproduce to pass on traits
overview Some animals are more fit than others because they are better at finding and attracting mates.
But there are natural reasons why certain species do not interbreed. overview But there are natural reasons why certain species do not interbreed.
Reproductive isolation Speciation happens when new species evolve, and the new populations become reproductively isolated from each other.
Reproductive isolation _____ ________ is when members of two populations cannot breed and produce fertile offspring. Reproductive isolation
Reproductive isolation Reproductive isolation is when members of two populations cannot breed and produce fertile offspring. Reproductive isolation
Reproductive isolation When this happens the populations have different _____ ____. Gene pools
Reproductive isolation When this happens the populations have different gene pools.
Reproductive isolation There are 3 types of reproductive isolation.
____ _____ is when they do different things. 1. Behavioral isolation ____ _____ is when they do different things.
Behavioral isolation is when they do different things.
1. Behavioral isolation This type of isolation is capable of interbreeding but have differences in courtship rituals.
1. Behavioral isolation Examples: Mating Songs Mating Dances Building nests
____ _______ is when organisms are separated from each other. 2. Geographic isolation ____ _______ is when organisms are separated from each other. Geographic isolation
Geographic isolation is when organisms are separated from each other.
2. Geographic isolation For example, populations are separated by: Bodies of water (rivers, lakes, oceans) Mountains Forest or meadow
2. Geographic isolation Why would squirrels, but not birds, be geographically isolated by a river?
These barriers do not always affect birds that can fly over them 2. Geographic isolation These barriers do not always affect birds that can fly over them
3. Temporal isolation _____ ________ is when two or more species reproduce at different times Temporal isolation
3. Temporal isolation Temporal isolation is when two or more species reproduce at different times
3. Temporal isolation Example: Early Spring vs. Late Spring