lab 7 & 8: demography

Define population.

A group of interbreeding individuals of the same species occupying a given area at a given time.

What is one technique used to study population ecology?

Constructing a life table, which uses information about age- and sex-specific mortality rates to determine patterns of survivorship and life expectancy.

What are the two ways life tables can be constructed?

By studying a cohort or constructing a static life table.

What is a cohort?

A group of individuals born at roughly the same time.

How do you construct a static life table?

Using data from cemeteries, historical documents, or even obituaries.

How does a static life table compare to a cohort life table?

Cohort studies are impractical for studying long-lived species as data spans from birth to death. Static life tables sample a given population at a snapshot in time.

What can the data from life tables be used for?

Constructing survivorship curves and examining age-specific mortality classes.

What are the three types of survivorship curves? Briefly describe each one.

Type I (highest probability of death in old age), II (intermediate between the others; such species have an equal chance of dying at any age), and III (highest probability of death at early age).

What does x represent in a life table?

The age class year (0 is first year, from birth to 1 year old, etc).

What does nx represent in a life table?

The number of individuals alive at the start of the age class x.

What does lx represent in a life table?

The proportion of the original population alive at age class x.

What does dx represent in a life table?

The number that die in age class x.

What does qx represent in a life table?

The mortality rate, calculated by dividing the number dying in age class x by the number alive at the beginning of that age class.

The study of the historical and modern population in Stockton is a (static/cohort) one.

Static.

What are the two time periods that the data for the cemetery was divided into?

<1950 life spans and >=1950 life spans.

What is the general format of the =if() function?

=if(logical_test, [value_if_true], [value_if_false])

What is the general format of the =averageifs() function?

=averageifs(average_range, criteria_range1, criteria1, [criteria_range2, criteria2], [criteria_range3, criteria3], ...])

What is the general format of the =countifs() function?

=countifs(criteria_range1, criteria1, ...)

What is the general format of the =countif() function?

=countif(range, criteria)

What would the function in a cell be if you wanted to put the life span for every individual that dies before 1950(the death years start in column F at cell 4 and the ages start in column G at cell 4)? The dataset ends at row 1403.

=if(F4<1950,G4,"")

What would the function be if you wanted to put the life span for every individual that dies after 1950 (the death years start in column F at cell 4 and the ages start in column G at cell 4)? The dataset ends at row 1403.

=if(F4>=1950,G4,"")

What would the function be if you wanted to put the life span for every MALE individual (the death years start in column F at cell 4 and the ages start in column G at cell 4)? The sexes are in column D starting in cell 4 as either F or M. The dataset ends at row 1403.

=if(D4="m",G4,"").

What would the function be if you wanted to put the life span for every female individual (the death years start in column F at cell 4 and the ages start in column G at cell 4)? The sexes are in column D starting in cell 4 as either F or M. The dataset ends at row 1403.

=if(D4="f",G4,"").

What would the function be if you wanted to calculate the average female life span for those dying before 1950 (the death years start in column F at cell 4 and the ages start in column G at cell 4)? The sexes are in column D starting in cell 4 as either F or M. The dataset ends at row 1403.

=averageifs(G4:G1403,D4:D1403,"f",F4:F1403,"<1950")

What would the function be if you wanted to calculate the average male life span for those dying before 1950 (the death years start in column F at cell 4 and the ages start in column G at cell 4)? The sexes are in column D starting in cell 4 as either F or M. The dataset ends at row 1403.

=averageifs(G4:G1403,D4:D1403,"m",F4:F1403,"<1950")

What would the function be if you wanted to calculate the average female life span for those dying after 1950 (the death years start in column F at cell 4 and the ages start in column G at cell 4)? The sexes are in column D starting in cell 4 as either F or M. The dataset ends at row 1403.

=averageifs(G4:G1403,D4:D1403,"f",F4:F1403,">=1950")

What would the function be if you wanted to calculate the average male life span for those dying after 1950 (the death years start in column F at cell 4 and the ages start in column G at cell 4)? The sexes are in column D starting in cell 4 as either F or M. The dataset ends at row 1403.

=averageifs(G4:G1403,D4:D1403,"m",F4:F1403,">=1950")

What was the age pyramid constructed in lab based on?

Percent mortality per age class per sex.