Question
According to the theory of natural selection where do variations in body size between the lizard species come from? random genetic change and sexual reproduction create variation within populations the island environment caused genetic changes in the lizards the lizards wanted to be different sizes, so new traits gradually appeared in the population lizards need to change to survive, so beneficial new traits are developed
Solution
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Otto
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Answer
The correct answer is: **random genetic change and sexual reproduction create variation within populations.**Here's why:* **Natural selection** acts upon *existing* variation. It doesn't create the variation itself. The variations in body size were already present in the lizard population due to: * **Random genetic change (mutations):** These are changes in the DNA sequence that can introduce new traits, including variations in body size. * **Sexual reproduction:** This process shuffles existing genes through recombination, creating new combinations of traits in offspring.* The other options are incorrect because: * **The island environment *selects* for advantageous traits:** While the environment plays a crucial role in natural selection by favoring certain traits, it doesn't directly *cause* the genetic changes. Lizards with sizes better suited to the island's resources are more likely to survive and reproduce, passing their genes (and thus their size) to the next generation. * **Organisms don't consciously choose their traits:** Evolution isn't a directed process based on what an organism "wants." Traits arise randomly, and those that are beneficial in a particular environment are more likely to be passed on. * **Beneficial traits aren't developed on demand:** While organisms adapt to their environments over time, this happens through the selection of existing variations, not the intentional development of new traits. The need to survive doesn't directly cause beneficial mutations to occur.