<P> A survivorship curve is a graph showing the number or proportion of individuals surviving to each age for a given species or group (e.g. males or females). Survivorship curves can be constructed for a given cohort (a group of individuals of roughly the same age) based on a life table . </P> <P> There are three generalized types of survivorship curves: </P> <Ul> <Li> Type I or convex curves are characterized by high age - specific survival probability in early and middle life, followed by a rapid decline in survival in later life . They are typical of species that produce few offspring but care for them well, including humans and many other large mammals . </Li> <Li> Type II or diagonal curves are an intermediate between Types I and III, where roughly constant mortality rate / survival probability is experienced regardless of age . Some birds and some lizards follow this pattern . </Li> <Li> Type III or concave curves have the greatest mortality (lowest age - specific survival) early in life, with relatively low rates of death (high probability of survival) for those surviving this bottleneck . This type of curve is characteristic of species that produce a large number of offspring (see r / K selection theory). This includes most marine invertebrates . For example, oysters produce millions of eggs, but most larvae die from predation or other causes; those that survive long enough to produce a hard shell live relatively long . </Li> </Ul> <Li> Type I or convex curves are characterized by high age - specific survival probability in early and middle life, followed by a rapid decline in survival in later life . They are typical of species that produce few offspring but care for them well, including humans and many other large mammals . </Li>

What type of survivorship curve is line a representative of