Question

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.

Short answer

Somatic gene therapy does not have a significant impact on human evolution because it only affects the individual receiving treatment and does not alter the genetic makeup of future generations. The changes made in somatic gene therapy are limited to somatic (non-reproductive) cells, which means they are not passed on to the offspring.

Step-by-step solution

Understanding gene therapy

Gene therapy is a treatment method that involves altering the genes inside a person's cells to treat or prevent disease. The main goal of gene therapy is to correct faulty genes, thus allowing the cells to function properly.

Understanding population genetics and evolution

Population genetics is the study of the genetic makeup of populations and how these gene frequencies change over time. Evolution, on the other hand, is the change in the genetic makeup of a population over generations. It occurs through mechanisms such as natural selection, genetic drift, gene flow, and mutation.

Understanding somatic gene therapy and germ-line gene therapy

Somatic gene therapy involves altering the genes within the affected individual's somatic (non-reproductive) cells. This means that the changes made are not passed on to the offspring. In contrast, germ-line gene therapy involves altering the genes within reproductive cells (sperm or eggs), which means that the changes made can be passed on to future generations.

Evaluating the effect of somatic gene therapy on human evolution

Somatic gene therapy targets specific individuals who are affected by a genetic disorder. Since the changes are limited to somatic cells and are not passed on to future generations, the effect of somatic gene therapy on human evolution is negligible. However, it can lead to improved health and quality of life for the individuals treated.

Evaluating the effect of germ-line gene therapy on human evolution

Germ-line gene therapy has the potential to affect human evolution since it targets reproductive cells and can be passed on to future generations. By correcting genetic disorders in germ cells, this therapy could potentially eliminate specific conditions from the gene pool. However, the long-term implications of germ-line gene therapy on human evolution are still uncertain and require further study. Ethical and social concerns also arise when considering germ-line gene therapy, as it could lead to intentional manipulation of human traits, like intelligence or physical appearance.

Conclusion

In light of population genetics and evolution, the criticism is valid only for germ-line gene therapy, as it has the potential to affect human evolution due to changes being passed on to future generations. Somatic gene therapy, on the other hand, has a minimal impact on human evolution since it only affects the individual receiving treatment and does not alter the genetic makeup of future generations.