Some critics have warned that the use of gene therapy to correct genetic disorders will affect the course of human evolution. Evaluate this criticism in light of what you know about population genetics and evolution, distinguishing between somatic gene therapy and germ-line gene therapy.

Verified step by step guidance

1. Step 1: Define somatic gene therapy and germ-line gene therapy. Somatic gene therapy involves altering the genes in specific body cells of an individual, without affecting their reproductive cells, while germ-line gene therapy involves changes to the genes in reproductive cells (sperm or eggs), which can be passed on to future generations.
2. Step 2: Explain how somatic gene therapy affects evolution. Since somatic gene therapy changes only the non-reproductive cells, these genetic modifications are not inherited by offspring and therefore do not directly influence the gene pool or the course of human evolution.
3. Step 3: Discuss the potential evolutionary impact of germ-line gene therapy. Because germ-line gene therapy alters the DNA in reproductive cells, these changes can be transmitted to future generations, potentially affecting allele frequencies in the population and thus influencing evolutionary processes.
4. Step 4: Consider the role of natural selection and population genetics principles. Even if germ-line gene therapy introduces new genetic variants, their impact on evolution depends on factors such as selection pressures, genetic drift, mutation rates, and gene flow within the population.
5. Step 5: Evaluate the criticism by integrating these points. The concern about gene therapy affecting human evolution is more relevant to germ-line gene therapy than somatic therapy. However, the actual evolutionary impact depends on how widely germ-line modifications are adopted and how they interact with natural evolutionary forces.

Key Concepts

Somatic Gene Therapy

Somatic gene therapy involves altering the genes in specific body cells of an individual to treat or prevent disease. These changes affect only the treated person and are not passed on to offspring, so they do not directly influence human evolution or the gene pool.

Germ-line Gene Therapy

Germ-line gene therapy targets the reproductive cells (sperm or eggs), causing genetic changes that can be inherited by future generations. This type of therapy has the potential to alter the human gene pool and thus could impact the course of human evolution.

Population Genetics and Evolution

Population genetics studies how gene frequencies change over time within populations due to factors like mutation, selection, and genetic drift. Evolution occurs when these gene frequencies shift, so interventions like germ-line therapy could influence evolutionary trajectories by changing heritable genetic variation.