1. Title: Explaining Evolution
INB Pg. 102
Population growth
Limiting resource
Inherited Variation
Natural Selection
Organism & Adaptation
Make this chart on the top & bottom ½ of your page.

2. Explaining Evolution
During courtship male peacocks display their large tails. It has been scientifically shown that males with larger tails get more mates. Explain how the peacocks tail might have evolved.

3. Explaining Evolution Population growth:
Pea cocks have the ability to reproduce at a rate which will cause the population to exceed the capacity of the environment.
Limiting resource:
Peacocks need access to a female mate to reproduce and pass on their traits. Mates are limited in number and peacocks must compete for them.
Inherited Variation:
In the peacock population, sexual reproduction, independent assortment, recombination and mutation cause variations in the size of peacock tails: small, med, lg. These variations can be inherited by their offspring.
Natural Selection:
Pea hens are a part of the peacocks environment. To reproduce, a peacock must get a pea hen to mate with him. Pea hens only let peacocks with the largest tails mate with them…therefore, longer tailed peacocks pass on their genes more often than shorter tailed peacocks.
Organism & Adaptation
Peacock & tail length

4. Explaining Evolution
The pepper moth lives in England. During the industrial revolution, smoke from the factories stained the bark of the trees dark. Over a decade or so, a new population of pepper moths that were dark in color was discovered.

5. Explaining Evolution Population growth:
Moths have the ability to reproduce at a rate which will cause the population to exceed the capacity of the environment.
Limiting resource:
Moths need tree space and the matching background to camouflage from predators (birds).
Inherited Variation:
In the moth population, sexual reproduction, independent assortment, recombination and mutation cause variations in the color of moths: peppered color and black color.
Natural Selection:
After the change of tree color, black moths blended in with the black trees and were less likely to be eaten…therefore, black moths survived, reproduced and passed on their genes to the next generation. The moth population changed over to time to a larger % of black color
Organism & Adaptation
Peppered moths & color

6. Explaining Evolution
The hammer orchid is a plant with a weird flower that looks like a female wasp. Male wasps try to mate with it and get tricked into carrying pollen from one plant to another helping the orchid reproduce.

7. Hammer orchid & flower structure
Explaining Evolution
Population growth:
Hammer orchids have the ability to reproduce at a rate which will cause the population to exceed the capacity of the environment.
Limiting resource:
Hammer orchids need male wasps to land on their flower and carry pollen to other hammer orchids. There is a limited number of available male wasps.
Inherited Variation:
In the hammer orchid population, sexual reproduction, independent assortment, recombination and mutation cause variations in the structure of orchid flowers. Some flowers highly resemble female wasps, and other flowers look less like female wasps.
Natural Selection:
Hammer orchid flowers that highly resemble female wasps, attract more male wasps and increase their opportunity to pollinate. Therefore, those hammer orchids are more likely to pass on their genes and the trait for flowers that highly resemble female wasps.
Organism & Adaptation
Hammer orchid & flower structure

8. Explaining Evolution
The top photo is a suspected ancestor of humans. The bottom photo is a human skull.
Notice the large braincase of the human skull. Propose an explanation for how this evolved.

9. Human & larger braincase size
Explaining Evolution
Population growth:
Humans have the ability to reproduce at a rate which will cause the population to exceed the capacity of the environment.
Limiting resource:
Male and female humans need the opposite gender to reproduce. There is also a limited amount of food/water available for the human population.
Inherited Variation:
In the human population, sexual reproduction, independent assortment, recombination and mutation cause variations in the size of human braincases & brains: small, med, lg. These variations can be inherited by their offspring.
Natural Selection:
Human braincase sizes directly relates to brain size and intelligence of an individual. A slightly larger brain will increase intelligence and result in a better hunter and provider. Healthier humans will attract more of the opposite gender to reproduce. Therefore… larger braincases will increase in a population.
Organism & Adaptation
Human & larger braincase size

10. Explaining Evolution Quiz
Population growth
Limiting resource
Inherited Variation
Natural Selection
Organism & Adaptation
Use your device to look up 1 unique adaptations.
Set up each of your ½ sheets of paper with the “Explaining Evolution” squares.
On the right hand side, write your adaptation scenario.

11. Explaining Evolution Quiz
Population growth
Limiting resource
Inherited Variation
Natural Selection
Organism & Adaptation
Use your device to look up 1 unique adaptations.
Set up each of your ½ sheets of paper with the “Explaining Evolution” squares.
On the right hand side, write your adaptation scenario.
Due Tomorrow!