Definition: overall repetitive or reflective pattern in the body of one individual of this taxon. eg: bilateral symmetry, rotational symmetry, radial symmetry
Definition: The initial mortality rate (IMR) represents the mortality rate independently of the ageing process. Though there are different methods, the IMR is typically estimated from the mortality rate prior to its exponential increase with age, which can be obtained from the mortality curve (by looking at the baseline mortality prior to its exponential increase) or, for mice, by using t = 0.25 in the Gompertz equation.
Definition: motion characterized by wave-like movement patterns that act to propel an animal forward. eg: crawling in snakes, or swimming in the lamprey. Typically utilized by limbless animals
Definition: The mortality rate doubling time (MRDT) is considered to be a measure of the rate of ageing. It is estimated from the slope of the Gompertz curve by: MRDT = 0.693/G where G is the exponential (Gompertz) mortality rate coefficient.
