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'.
From Wikipedia, the free encyclopedia. The molecular clock (based on the molecular clock hypothesis (MCH)) is a technique in molecular evolution that uses fossil constraints and rates of molecular change to deduce the time in geologic history when two species or other taxa diverged.he molecular clock alone can only say that one time period is twice as long as another: it cannot assign concrete dates. To achieve this, the molecular clock must first be calibrated against independent evidence about dates, such as the fossil record.