Change by Natural Selection

4 components for change--V.I.S.T V = Variation: Differences among individuals of the same species. Differences in phenotypes.

Variations = Differences

Humans

What are the variations for Zebra?

What are the variations for Lady Bugs?

What are the variations for Giraffes ?

What are the variations for Flamingos?

Pick any animal you can think of and draw 3 pictures in your Variation box showing the variations among that species

4 components for change--V.I.S.T = Inheritance: Physical traits (phenotypes) are inherited from parents and are passed on to offspring in DNA.

4 components for change--V.I.S.T = Selection: Nature is unforgiving and plants and animals must compete and fight to stay alive. Organisms with traits (phenotypes) that are favorable to their survival get to live and pass on their genes to the next generation.

4 components for change--V.I.S.T T = Time: Change takes time. Change can happen in a few generations, but major change, often takes long periods of time.

How humans have evolved changed species IGNORE THIS SLIDE FOR SUB ON 4-8-16 How humans have evolved changed species Artificial Selection – Humans select the most desirable traits in organisms and breed those individuals -Desired trait appears more often -Less desired traits begin to disappear

130,000 years ago humans began keeping dogs 150 years of selective breeding

How do I describe change by natural selection? There is a population of rabbits who have moved to the snow because the food they eat has died out. 90% of the population is light to dark brown. 10% is white. What kind of changes do you think will happen to this population of rabbits? Explain how these changes will occur.

What kind of changes do you think will happen to this population of rabbits? Explain how these changes will occur: The rabbits that are ______________ are more likely to survive and reproduce because _____________________________________. The rabbits that are _________________ will slowly die off because _____________. Because of this, slowly over time the majority if not all the rabbits will be ____________________.

Nature “Selects” Natural selection -Environments change and favor individuals with specific traits good for the new environment—leading to change in how the species looks/behaves or extinction Change in environment = Change in species

How do species become adapted to their environment? Organisms do not choose to adapt to their environment Little changes add up over long periods of time -Individuals with the right traits for their environment reproduce and you see more of them -Individuals who do not have the right traits die and you see less individuals until they are all gone

http://www.youtube.com/watch?v=huxDnZs2_OQ https://www.youtube.com/watch?v=0IREyspugXU

Bird/Rat Questions How did this environment change? Which mouse trait (phenotype) is most likely to survive and reproduce? Why? Did the change in the environment change the look of this species? Explain.

10. Natural Selection The traits that help an organism survive in a particular environment are “selected” in natural selection

AKA: Survival of the fittest Survival of the fittest is not about being the biggest and strongest its about having the right trait to survive Fitness – surviving + reproduce -Low fitness =dying and leaving few offspring *do not pass on your genes -High fitness = surviving with many offspring *pass on your genes

What Darwin Observed

Answer the following question with your face partner  Why do some biologists say that “fitness is measured in grandchildren?” <Be ready to present>

Answer the following question with your shoulder partner Why is survival of the fittest not always about being the biggest or fastest or strongest? Give an example to support your answer <be ready to present>

1. Natural selection is the process by which a.the age of selected fossils is calculated. b.organisms with traits well suited to their environment survive and reproduce more successfully than organisms less suited to the same environment. c.acquired traits are passed on from one generation to the next. d.All of the above

2. Natural selection could not occur without a.genetic variation in species. b.stable environments. c.competition for unlimited resources. d.gradual warming of the Earth.

3. Populations of the same species living in different places a.do not vary. b.always show balancing selection. c.are genetically identical to each other. d.become increasingly different as each population becomes adapted to its own environment.

4. An organisms ability to survive and pass on its genes to future generations is called A. adaptation B. natural selection C. fitness D. artificial selection