Question

darwin & natural selection
name:
in each of the following scenarios, identify the parts of darwins theory.

1. a species of moth has 2 varieties of wing color: brown and white. as winter approaches, the trees where the moths live lose their leaves. the moths predators are birds who hunt for the moths as they rest on the dark tree bark. every moth lays 100 eggs, but only about 10 from each egg - cluster live to adulthood.

which moth do you think will be selected against?
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which trait is favorable? why?
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what are the variations in this population?
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how does this species overproduce?
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how will this species change over time?
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1. only one out of 1,000 sea turtles survives to adulthood. from the moment they hatch, sea turtles must strive for survival. they race across the beach and battle the waves moments after their birth. throughout the time, predation stalks them for an easy meal. some sea turtles are faster than others.

which sea turtle do you think will be selected against?
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which trait is favorable? why?
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what are the variations in this population?
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how does this species overproduce?
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how will this species change over time?
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1. storks are a species of bird that only has the time and energy to provide for one chick. storks lay two eggs. after the eggs hatch, the birds feed both chicks for a week. after a weeks time, the smaller chick is thrown out of the nest and left to fend for itself. from then, the parents focus their efforts only on the larger chick.

which stork do you think will be selected against?
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which trait is favorable? why?
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what are the variations in this population?
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how does this species overproduce?
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how will this species change over time?
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Explanation:

1. Moth Scenario

• Selected against: White - colored moths will be selected against as they are more visible on the dark tree - bark during winter when trees lose leaves, making them easier prey for birds.
• Favorable trait: Brown wing color is favorable because it provides camouflage on the dark tree - bark, reducing the likelihood of being eaten by predators.
• Variations: The variations in the population are the two wing - colors, brown and white.
• Overproduction: Each moth lays 100 eggs, but only about 10 from each egg - cluster live to adulthood, indicating high egg - laying numbers compared to survival rates.
• Long - term change: Over time, the proportion of brown - winged moths in the population is likely to increase as they have a higher survival rate and are more likely to reproduce.

• Selected against: Slower sea - turtles will be selected against as they are more vulnerable to predation while racing across the beach and battling the waves after birth.
• Favorable trait: Speed is a favorable trait as faster sea - turtles have a better chance of reaching the safety of the ocean before being caught by predators.
• Variations: Some sea - turtles are faster than others, indicating a variation in speed within the population.
• Overproduction: Only one out of 1,000 sea - turtles survives to adulthood, showing that a large number of eggs are laid but few survive, which is overproduction.
• Long - term change: Over time, the average speed of sea - turtles in the population may increase as faster individuals are more likely to survive and reproduce.

• Selected against: The smaller chick will be selected against as it is thrown out of the nest and left to fend for itself, reducing its chances of survival.
• Favorable trait: Larger size in chicks is favorable because storks focus their efforts on the larger chick after one week, increasing its chances of survival and development.
• Variations: Size differences between the two chicks (larger and smaller) are the variations in the population.
• Overproduction: Storks lay two eggs but can only provide for one chick, indicating overproduction in terms of egg - laying relative to their ability to care for offspring.
• Long - term change: Over time, the proportion of larger - sized chicks in the population may increase as they have a higher survival rate.

Answer:

• Which moth do you think will be selected against? White moths.
• Which trait is favorable? Why? Brown wing color, because it provides camouflage on dark tree - bark.
• What are the variations in this population? Brown and white wing colors.
• How does this species overproduce? Each moth lays 100 eggs, but only about 10 from each egg - cluster reach adulthood.
• How will this species change over time? The proportion of brown - winged moths will likely increase.

2. Sea Turtle Scenario