Quality vs. Quantity

K-selected - “quality”

• Few offspring, heavy parental care to protect them

• Usually reproduce many times

  • Ex: most mammals, birds

• Long lifespan, long time to sexual maturity = low biotic potential = slow pop. growth rate

  • More likely to be disrupted by environmental change or invasive

R-selected - “quantity”

• Many offspring, little to no care

• May reproduce only once

  • Ex: insects, fish, plants

• Shorter lifespan, quick to sexual maturity = high biotic potential = high pop. growth rate

  • More likely to be invasive

  • Better suited for rapidly changing environmental conditions

K-selected

• Low biotic potential (rep. rate) = hard for pop. to recover after a disturbance (env. change)

• High parental care means death of parent = death of offspring

• Invasives (usually r) outcompete for resources with high biotic potential & rapid pop. growth

• Less likely to adapt & more likely to go extinct

R**__-selected __**

• High biotic potential (rep. rate) = more rapid pop. recovery after disturbance

• Low parental care means death of parent doesn’t impact offspring

• Not as impacted by invasive species since their pop. grow quickly

  • More likely to be the invasive

• Larger pop. & faster generation time = higher chance of adaptation & lower chance of extinction