Homework 08: Data Visualization

Please turn in one script with code and comments to answer the questions below.

For this homework, you will try some ggplot2 exercises with morphological data from Galapagos finches, which is available from BIRDD: Beagle Investigation Return with Darwinian Data at http://bioquest.org/birdd/morph.php. It is originally from Sato et al. 2000 Mol. Biol. Evol. http://mbe.oxfordjournals.org/content/18/3/299.full.

I've included some code to get you started. My code downloads the data, cleans it up a bit, and restricts it to data from one island: hw08-clean-birdd.R. There are columns for taxon, sex, wing length, beak height, and upper beak length. Use what you have learned about ggplot2 to make informative and beautiful figures. think about how to use aesthetics (x, y, color, etc) and faceting.

Aim for publication-quality figures.


Question 1

Use ggplot to show me how wing length ("wingl") is related to taxon and sex. Decide what is the best geom and aesthetics. Explain what other geoms you tried before you decided.

Question 2

Investigate the relationship between wing length and beak height across taxa and sex. Is any one taxon morphologically distinct from the others? Create a graph to illustrate your answer.

Question 3

Go back and look at hw08-clean-birdd.R. Why did I use the strip.white argument to read.csv? What problem(s) in these data show up if you omit that argument? Try it out and explain.

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