Question
What is the role of genes in evolution?
Only genes can be acted on by natural selection.
The genes of most surviving parents have only dominant alleles.
Only traits that are controlled by genes can be acted on by natural selection.
Parents with recessive genes die from overproduction.
Answers
GPT-4o mini
The role of genes in evolution is fundamentally tied to how genetic variation is introduced and maintained in populations, which in turn affects the process of natural selection. Here’s a closer look at each of the statements you provided:
1. **Only genes can be acted on by natural selection.**
- This statement is partially true. Natural selection acts on phenotypes (observable traits), which are influenced by genes. However, it's important to note that environmental factors also play a significant role in shaping these traits and the selective pressures that drive evolution.
2. **The genes of most surviving parents have only dominant alleles.**
- This statement is misleading. While dominant alleles can have a noticeable effect on phenotype, both dominant and recessive alleles contribute to the genetic diversity of a population. Evolution relies on the variation brought about by all types of alleles, not just dominant ones.
3. **Only traits that are controlled by genes can be acted on by natural selection.**
- This statement is generally accurate. Natural selection affects traits that have a genetic basis, as these traits can be passed down to the next generation. However, it's worth noting that environmental factors can also influence expression and viability, but heritable traits are the ones that evolve over generations.
4. **Parents with recessive genes die from overproduction.**
- This statement is incorrect and does not accurately reflect how genetics and natural selection work. Recessive alleles can persist in a population even if they are not expressed phenotypically, especially if they are masked by dominant alleles. Overproduction of offspring does create competition for resources, but it does not directly lead to the death of parents based on recessive alleles alone.
In summary, genes provide the heritable basis for traits that are subject to natural selection, influencing the direction of evolutionary change. Genetic diversity, including both dominant and recessive alleles, is crucial for the adaptability and resilience of populations over time.
1. **Only genes can be acted on by natural selection.**
- This statement is partially true. Natural selection acts on phenotypes (observable traits), which are influenced by genes. However, it's important to note that environmental factors also play a significant role in shaping these traits and the selective pressures that drive evolution.
2. **The genes of most surviving parents have only dominant alleles.**
- This statement is misleading. While dominant alleles can have a noticeable effect on phenotype, both dominant and recessive alleles contribute to the genetic diversity of a population. Evolution relies on the variation brought about by all types of alleles, not just dominant ones.
3. **Only traits that are controlled by genes can be acted on by natural selection.**
- This statement is generally accurate. Natural selection affects traits that have a genetic basis, as these traits can be passed down to the next generation. However, it's worth noting that environmental factors can also influence expression and viability, but heritable traits are the ones that evolve over generations.
4. **Parents with recessive genes die from overproduction.**
- This statement is incorrect and does not accurately reflect how genetics and natural selection work. Recessive alleles can persist in a population even if they are not expressed phenotypically, especially if they are masked by dominant alleles. Overproduction of offspring does create competition for resources, but it does not directly lead to the death of parents based on recessive alleles alone.
In summary, genes provide the heritable basis for traits that are subject to natural selection, influencing the direction of evolutionary change. Genetic diversity, including both dominant and recessive alleles, is crucial for the adaptability and resilience of populations over time.