Describe what each of the above phenotypic distributions is showing in words.
In a population of 100 people, 13 people were between 5’0” and 5’4”, 75 people were between 5’5” and 5’9”, and 12 people were between 5’10” and 6’2”. Which type of selection is this an example of?
Starlings produce an average of five eggs in each clutch. If there are more than five, the parents cannot adequately feed the young. If there are fewer than five, predators may destroy the entire clutch. Which type of selection is this an example of?
The rocks at the bottom of a Mt. Hood stream are either black or white. Snails that live on these rocks are a range of color from solid black to gray to solid white. A local freshwater fish loves to munch on these snails, but it cannot see the solid black or solid white snails when the snails are on matching rocks. Grey does not blend into either rock color and is much easier to see. Which type of selection is this an example of?
In a lake in South Africa, guppies are eaten by the pike fish, and the larger the guppy, the more difficulty it has escaping its pike fish predator. Which type of selection is this an example of?
For the following scenarios, determine if it is an example of intersexual selection or intrasexual selection AND explain how you know. A bird of paradise fluffs his bright feathers to attract a female.
2 bucks battle each other with their antlers to win the right to mate with the doe
Dawson bees fight to the death in order to mate as many times as possible
A male donkey is mated with a female horse. The resulting offspring is a mare, but the mare is barren, therefore concluding that donkeys and horses are different species. Which type of isolation is responsible for this outcome? Explain.
A male bird of paradise tries to impress a female of another species with a dance, but the female is only attracted to a song. Which type of isolation is responsible for the speciation in this scenario? Explain.
A species of butterflies mates in early spring, while another mates in mid-summer. After mating and laying the eggs, the butterflies of either species die, which would prevent them from ever mating with each other. Which type of isolation is responsible for the speciation in this scenario? Explain.
A population of fish is split in half when the Isthmus of Panama formed, separating the Atlantic and Pacific Oceans. Over evolutionary time, each population adapted to the unique environments on either side, resulting in two different species. Which type of isolation is responsible for the speciation in this scenario? Explain.
Porcupines in the United States have quills (spines) that are attached to their skins. When they feel threatened, they can tense up their bodies causing the quills to “shoot out”. These spiny quills can pierce the skin of attacking animals, causing injury and pain. Although not closely related to the porcupine, hedgehogs that live throughout parts of Europe also have protective spines that they use to defend themselves from attacking animals. Which pattern in evolution is this an example of? Explain.
The flower that blooms from the saguaro cactus has evolved a bright, white coloration to attract many of the bats they rely on to pollinate (fertilize) their flowers. Since they rely on the bats, they have also adapted to opening their flowers at night, when the bats are active. The bats have also adapted to the cactus by developing the ability hover (slightly) above the flowers and a long tongue that can reach deep inside the flower. Which pattern in evolution is this an example of? Explain.
Grizzly bears and polar bears share a common ancestor, but each has distinct adaptations suitable for their environments. Grizzly bears are brown to be well-camouflaged against the backdrop of their temperate forest habitat, whereas polar bears are white to blend in with the ice and snow in the Arctic Circle. Which pattern in evolution is this an example of? Explain.
Garter snakes feed on the rough skinned newt. Over evolutionary time, the newts had adapted for survival by producing a toxic chemical in their skin. In response, the snakes had adapted by developing a resistance to the toxin, resulting in the newts producing an even higher concentration of the toxin. Which pattern in evolution is this an example of? Explain.
Essays – You must answer the essay. Write your response on the back of your answer sheet or on a separate piece of paper. The essay must be at least 5 sentences to be considered for full credit. The essay is worth 5 points. List the 5 conditions that must be met in order for a population to be in equilibrium. Explain in detail why populations are almost never in equilibrium (you should have a reason for why each condition can be violated).