# Biology, Eighth Edition (Raven)

## Chapter 55: Population Ecology

### Death Calculator

What assumptions are built into estimations of life expectation? This animation calculates a life expectancy based on information used by insurance companies. Data is collected on the number of people dying in each age class (year of age) for a particular year. This pattern is assumed to continue unchanged into the future. To calculate the average of life expectancy for a given age, the average age of all the people dying that are older than that age is calculated. For example, to calculate the average life expectancy of an 18 year old male you would calculate the average age of all males over the age of 18 dying in that year. This is a technique that can provide useful information. However the assumption that the pattern of mortality will not change over time is clearly false. Life expectancy of people in western nations has been increasing most of the time over the last several centuries.

View the animation below, then complete the quiz to test your knowledge of the concept.

 1. According to this death calculator, how many years remaining does a female born in 1985 have? A) 50.1 years B) 51.1 years C) 58.2 years D) 59.2 years 2. According to this death calculator, how many years remaining does a male born in 1985 have? A) 50.1 years B) 51.1 years C) 58.2 years D) 59.2 years 3. According to the graph what has happened to life expectancy between 1900 and 2000? A) it has increased B) it has decreased C) it has not changed D) there is no clear pattern 4. What happened in 1918? A) black plague B) heat wave in 1917 decreased conception rates C) smallpox epidemic D) United States had its worst influenza outbreak 5. At the height of the epidemic how many people died in New York in one day? A) 493 B) 712 C) 851 D) 1119