pituitary dwarfism. caused by hyposecretion of growth hormone by pituitary gland at an early age, it slows growth and causes short and proportional stature; it is a congenital condition that can be treated during childhood with growth hormone therapy.aused by hyposecretion of growth hormone by pituitary gland at an early age, it slows growth and causes short and proportional stature; it is a congenital condition that can be treated during childhood with growth hormone therapy.
Molecular dating analyses allow evolutionary timescales to be estimated from genetic data, offering an unprecedented capacity for investigating the evolutionary past of all species. These methods require us to make assumptions about the relationship between genetic change and evolutionary time, often referred to as a 'molecular clock'.
Radiometric dating (often called radioactive dating) is a technique used to date materials such as rocks or carbon, in which trace radioactive impurities were selectively incorporated when they formed.he precision of a dating method depends in part on the half-life of the radioactive isotope involved. For instance, carbon-14 has a half-life of 5,730 years. After an organism has been dead for 60,000 years, so little carbon-14 is left that accurate dating can not be established.