# Adult vs Newborn Size (Graphing)

Larger organisms have larger offspring. We want to explore the form of this relationship in mammals.

Check to see if `Mammal_lifehistories_v2.txt`

is in your working directory.
If not download it
from the web.
This is tab delimited data, so you’ll want to
use `sep = "\t"`

as an optional argument when calling `read.csv()`

. The `\t`

is
how we indicate a tab character to R (and most other programming languages).

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 import only the first 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.

- Graph adult mass vs. newborn mass. Label the axes with clearer labels than the column names.
- It looks like there’s a regular pattern here, but it’s definitely not linear. Let’s see if log-transformation straightens it out. Graph adult mass vs. newborn mass, with both axes scaled logarithmically. Label the axes.
- This looks like a pretty regular pattern, so you wonder if it varies among different groups. Graph adult mass vs. newborn mass, with both axes scaled logarithmically, and the data points colored by order. Label the axes.
- Coloring the points was useful, but there are a lot of points and it’s kind
of hard to see what’s going on with all of the orders. Use
`facet_wrap`

to create a subplot for each order. - Now let’s visualize the relationships between the variables using a simple
linear model. Create a new graph like your faceted plot, but using
`geom_smooth`

to fit a linear model to each order. You can do this using the optional argument`method = "lm"`

in`geom_smooth`

.

*Expected outputs for Adult vs Newborn Size:*

*1*

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*5*