This is a long 6-8 page report.
We have created a file with the color spectral analyses of the belly (on newts) and red limb segments on the Ensatina salamanders.
Newts from three areas were sampled:
Pescadero (we collected these)
East Bay
Sierras
Ensatina from 6 areas were sample (abbreviations refer to subspecies of Ensatina eschscholtzii e, o, or x as given by David Wake.
Eeo – Pescadero
Eeo – Swanton road (we collected these)
Eex – Campus (last years class collected these)
Eex – Sierras (Shawn collected these)
Eee – s Pajaro R (Shawn collected these)
From this data you have to argue which of the Ensatina are cryptic populations and which are mimetic on Newts.
We have coded the columns for geographical location and species
1) You should first “edit a criteria” in the Manage part of the menu and set
species = “Ensatina”
Then run an ANOVA with LM (red-green) as the Y and geographical location as the X
This gives you the P-value for differences among all populations as well as all of the pairwise combinations of Posthoc tests. Posthoc tests are very similar to a T-test (see Bruce’s lecture on statistics).
Also carry out the MS (yellow-blue) comparison.
2) You should then “edit a criteria” in the Manage part of the menu and set
species = “Taricha” (e.g., newt).
Then run an ANOVA with LM (red-green) as the Y and geographical location as the X
This gives you the P-value for differences among all populations as well as all of the pairwise combinations (e.g., Post-Hoc tests).
Also carry out the MS (yellow-blue) comparison.
3) Finally you should create a column with your hypothesis of:
model
mimic
cryptic
labeled as categories
and run the same ANOVA models.
4) We have also included a number of other variables in the file (based on Alexis’ lecture on color). Test whether there is any additional information in these channels for color besides the information encoded in LM and MS. We have included a paper on Endler’s tome of color and color perception where he derived LM and MS color spaces (see drawer 13). You can cite this paper as well.
5) From these analyses, you should be able to write a 6-8 page paper on the evolution of mimicry and crypsis in the different subspecies of Ensatina. The issues you include in the discussion can be quite free-form, but you should at the very least include a discussion of the phylogeographic paper by David Wake which gives you the history of the Ensatina.
In addition, you should include predictions about what you would expect from the model study that we have carried out on campus. You predictions should relate to your analysis and interpretation of color (signal) evolution of the Ensatina data.
I have also put my copy of Stebbins in the laboratory. Read the sections on the Newt and Ensatina and work those into your discussion (and introduction) to introduce the reader to basic natural history.
Finally, you should also search the literature for other papers that have used models to test hypotheses of color signal evolution (e.g., Aposematic models, mimicry, and crypsis, etc.).
Thus, your ref list should include Stebbins, Endler, Wake and any other papers you find in your literature survey.
We have spelled out what is required in this long report. In the future, you will have much more leeway in what tests you do and what references you include. HINT: Start early so you can ask questions when they come up!! This is especially true for the discussion and introduction sections.
Cheers
Barry, Bruce, and Alexis