What is the Difference Between Neoteny and Progenesis?

Neoteny and progenesis are both forms of heterochrony, which refers to the change in the relative timing of developmental events in an organism. They result in paedomorphism, where an organism retains juvenile traits in adulthood. However, they differ in the aspect of development they affect:

• Neoteny: This is the slowing down of somatic development, resulting in reproduction happening at an earlier stage compared to the ancestral form. In neoteny, the somatic cell growth is retarded, while the germ cell growth remains normal. This is commonly observed in young individuals. Neoteny is also seen in domesticated animals, where abundant resources and lowered competition allow them to mature and reproduce more quickly than their wild counterparts.
• Progenesis: This is the speeding up of the germ line, also resulting in paedomorphosis. In progenesis, the somatic cell growth remains normal, while the germ cell growth is accelerated, leading to earlier sexual maturation. This condition is much faster and rapid compared to neoteny.

In summary, the key difference between neoteny and progenesis is the type of paedomorphism they show. Neoteny displays retarded somatic cell growth and normal germ cell growth, while progenesis exhibits accelerated germ cell growth and normal somatic cell growth.

Comparative Table: Neoteny vs Progenesis

Neoteny and progenesis are both mechanisms that result in pedomorphosis, a phenomenon where an organism retains juvenile characteristics into adulthood. Here is a table comparing the differences between neoteny and progenesis:

Both neoteny and progenesis lead to pedomorphosis and show juvenile characteristics. They both take place due to heterochronic mutations and are related to the development processes.