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Monarch butterflies in the eastern regions of North America migrate thousands of miles to an area in Mexico in the fall and then back to northern regions in the spring. Explain how this migration behavior came to be established in this species. a. Each new generation learned the migration behavior by observing older generations and mimicking their behavior patterns. b. In very early generations of this species, a few individuals found that migration improved their chances for survival and taught their young to carry on the behavior. c. Individuals that migrated survived through the winter, whereas individuals that did not migrate died, leading to selection for migration in later generations. d. When this butterfly emerged as a new species, by chance it inherited the genetic material that underlies long-distance migration behavior from its ancestor.

Step by step solution

01

- Understanding the Question

The question is asking to explain how the migration behavior of Monarch butterflies became established in the species. This involves understanding survival advantages and evolutionary mechanisms.

02

- Evaluating Option a

Option a suggests that the migration behavior is learned through observation and mimicry. This is less likely for butterflies as their lifecycle doesn't involve prolonged parental care where learning behaviors would occur.

03

- Evaluating Option b

Option b implies that early individuals discovered the migration benefit and taught it to offspring. This is also unlikely since most insect behaviors, including migration, are not learned but instinctual and genetically programmed.

04

- Evaluating Option c

Option c proposes natural selection: individuals that migrated survived winters, while non-migratory ones did not. This would cause migration to be favored in the population, leading to a heritable trait over generations.

05

- Evaluating Option d

Option d suggests that migration behavior was randomly inherited from ancestors upon speciation. This overlooks the role of natural selection in refining advantageous traits.

06

- Choosing the Correct Answer

Option c is the most plausible as it explains migration through natural selection, where surviving individuals' traits are passed on, leading to the establishment of this behavior in the species over many generations.

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Key Concepts

These are the key concepts you need to understand to accurately answer the question.

Natural Selection

Natural selection is a fundamental concept in biology, describing how certain traits become more common in a population over generations because they provide some advantage. For example, in the case of Monarch butterflies, those that migrated to warmer climates during the winter were more likely to survive and reproduce. Over time, this behavior became common in the population because the migrating butterflies lived longer and had more offspring. The non-migratory butterflies, on the other hand, did not survive the harsh winters and thus did not pass on their non-migrating genes. This constant filtering of advantageous traits over generations is what drives evolution and adaptation in species.

Inheritance of Traits

Inheritance of traits explains how characteristics are passed from one generation to the next through genetic material. In Monarch butterflies, the ability to migrate is coded into their DNA. Though it might seem like young butterflies would need to be taught how to migrate, this behavior is actually instinctual. The ones that had the genetic code allowing them to migrate survived better and reproduced more successfully. Hence, their offspring inherited these beneficial traits. Over many generations, this genetic material became widespread in the Monarch butterfly population, ensuring that almost all Monarchs inherited this crucial survival skill.

Evolution of Behaviors

The evolution of behaviors, such as migration, is shaped by environmental pressures that favor certain behaviors over others. In early generations, some butterflies might have accidentally migrated and found that the warmer climate helped them survive. Those butterflies would then have more offspring, passing along their migratory instincts. Given enough time, natural selection would mean that migratory behaviors become ingrained in the species. Hence, migration for Monarch butterflies is not just random but a result of millions of years of evolutionary refinement, ensuring they maintain an advantage in their natural habitat.

Survival Advantage

The concept of survival advantage refers to the benefits that certain traits provide in an organism's ability to survive and reproduce. For Monarch butterflies, migrating to warmer climates during the winter is an essential survival strategy. This behavior ensures they avoid harsh conditions where food is scarce and temperatures can be fatal. Butterflies that migrate can find food and suitable climates, making it more likely they'll survive to adulthood and reproduce. Non-migratory butterflies, however, would face severe challenges that could prevent them from surviving and passing on their genes. Thus, migration offers a clear survival advantage that has been naturally selected for over generations.