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Natality and Survivorship determine reproductive rates

We determine reproductive rates using life tables. Life tables are an account book of death, giving us information such as the age at which females give birth and the age at which a population dies. This is a little more confusing for plants because their asexual behavior does not allow for the separation of male and female.


Rate of Population Increase

rate of increase -describes instantaneous population growth

Stable Age Distribution:

A stable age distribution is one in which the properties of each age class remain the same, even though the

population is growing.

Population Growth is Limited by the Environment


We have run out of food

Populations Fluctuate

Low Population may Equal EXTINCTION!!

Are Extinctions Spread Evenly Throughout our Perception of Time in this Reality?


Permian period (225 mil.yrs ago)- 90% of shallow-water marine invertebrates disappeared

Cretaceous period (65-125 mil.yrs ago)-dinosaurs

Pleistocene (11,550-10,000 yrs ago)-woolly mammoth, giant deer, mastodon, giant sloth



Laughing Owl, (Sceloglaux albifacies)

Native to New Zealand, this owl was known for its call that sounded as soon as it awakened every night. It disappeared because humans introduced animals that easily hurt the bird.


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