It makes sense that larger organisms have larger offspring, but what the mathematical form of this relationship should be is unclear. Let’s look at the problem empirically for mammals.
Download some
mammal life history data from the web.
You can do this either directly in the program using read.csv()
or download
the file to your computer using your browser, save it in the data
subdirectory, and import it from there.
When you import the data there are some extra blank lines at
the end of this file. Get rid of them by using the optional read.csv()
argument nrows = 1440
to select the valid 1440 rows.
Missing data in this file is specified by -999
and -999.00
. Tell R that
these are null values using the optional read.csv()
argument,
na.strings = c("-999", "-999.00")
. This will stop them from being plotted.
facet_wrap
to
create subplot for each order.geom_smooth
to fit a linear model to each order. You can do this using the
optional argument method = "lm"
in geom_smooth
.