Compare r-selected and K-selected species for the following life history traits. One of your answers should discuss survivorship curves. 

• lifespan
• juvenile mortality
• body size

R- selected species have short life-spans, high juvenile mortality and small body sizes. K-selected species have long lifespans, lower juvenile mortality and larger body size.

Survivorship curves of r-selected species and k-selected species are very different. R-selected species have a high death rate and few live to old age. K-selected species have a low death rate and many individuals live to old age.

Here's a sample survivorship curve from the Campbell Biology Chapter 53.

The lower curve represent r-selected species that have high juvenile mortality seen by the dip at the beginning of the graph. The upper curve represent k-selected species with low juvenile mortality seen by the plateau remaining at the top of the graph.

The reason that k-selected species have low juvenile mortality is because they have fewer offspring and have more investment in nurturing each offspring lowering juvenile mortality. R-selected species have many offspring knowing that many of them will die, meaning that the more offspring they have the higher the chance that at least a few make it to maturity and old age.

Please see the attached file for the complete solution