Dear EvolDir members, A few days ago I posted a question in EvolDir regarding "Suggestions for inter-species competition experiment". Many of you replied and made very useful suggestions. I am posting these replies since I consider they will be of use to many of you. I would like to thank all those that replied, I think I now have a good idea of how to se up some experiments both in the field and in the lab. Thanks a lot. Aris -----Compilation of responses----- Hello, We are doing this kind of teaching here in Montpellier with around 100 students. We are using Chlamydomonas for that purpose. It grows fast, does not require sterile equipment and you can order many different strains from the web. We have two sets of experiments, one where students measure the outcome of competition between a strain of Chlamydomonas and Klebsormidium sp. (another algae that we isolated from a soil sample) and a second set where they study competition between two strains of Chlamydomonas, the wild type one (CC125) and one that resists to an herbicide (strain CC2473 that resists to atrazine). The first experiment focus on interspecific competition while the second is designed to study natural selection. The way we organize this is that, for each experiment, small groups of 4-5 students run a single replicate of each treatment. We then pool all results (using a web interface) and all students have to analyze the complete data set. The most interesting part of this is that most of the time some aspects of the experiment fail. Students have to deal with that and must also cope with heterogeneity in data. I think these issues are realy central in educating students to scientific thinking. And still, students seldom face these problems in the context of a class. If you want more details on these experiments, feel free to ask! On the web-site from which you can order the strains (http://www.chlamy.org), you will also find some teaching kits, I think. I never used these, but it might proove useful in your case. Sincerely, Jean-Baptiste Ferdy Institut des Sciences de l'Évolution de Montpellier CNRS UMR 5554 Université Montpellier 2 34 095 Montpellier cedex 05 tel. +33 (0)4 67 14 42 27 fax +33 (0)4 67 14 36 22 ----- Dear Aris I took an undergraduate class of Ecology in Colombia where we play "Othello" to understand concepts of inter-species competition in Ecology. Do you know this game? It's a game based on strategy and you "compete" with your opponent for space in a table of 8x8 spaces. Here is a link in wikipedia where is explained the game. http://en.wikipedia.org/wiki/Reversi Good look in your class. Ivania ----- Hello, Our department has an undergraduate ecology lab that focuses on competitive exclusion, using spider species as the study organisms. Students measure web diameter, angle, distance from ground, and an approximation of strand density. They use chi-square and we encourage them to test between ecologically similar species (e.g. between two different orb weavers). I can email you a .pdf of the lab if you like. Good luck! Jen Hamel jahamel@mizzou.edu University of Missouri - Columbia Tel. 573-882-4189 www.biosci.missouri.edu/cocroft/Jennifer/jennifer.htm ----- Hello, I teach an undergraduate ecology class, and use a great set of software called EcoBeaker (SimBiotic Software: http://www.ecobeaker.com/) to help teach a number of ecological concepts. The simulation software is very easy to use, the directions are clear, and the labs are visually appealing. There is often some control over the options if you want to play around, and students can output data and graphs for further analysis. They also provide full lab exercises, with good questions, to go along with each lab. I've had a very good experience with this program, and its companion, EvoBeaker. I realize this isn't a field or laboratory demonstration per se, but it may be appropriate for such a large class. Cheers, Maarten Vonhof Assistant Professor, Department of Biological Sciences and Environmental Studies Program Western Michigan University 1903 W. Michigan Avenue Kalamazoo, MI 49008-5410 Phone: (269) 387-5626, Fax: (269) 387-5609 E-mail: maarten.vonhof@wmich.edu ----- Hi Aris, I run an interspecific competition experiment in my Ecology lab using Tribolium flour beetles based on the classic experiments of Park. I have up to 100 students so the lab is suitable for large groups. Do you run the lab with all the students or divide them into groups? If you have the facilities to divide them into smaller groups, this experiment might work as it requires students to spend time at the microscope sorting out the beetles. I have attached a copy of the lab. Let me know if you have any questions Cheers Mary Alice Coffroth ----- This paper may be of interest [The Journal of Applied Ecology, Vol. 13, No. 1, (Apr., 1976), pp. 211-216] . Mustard and cress seed can be bought in bulk and grown on wet tissue paper - therefore minimal costs with a large class. Quentin ----- Dear Aris, I have attached a paper I have coming out in J Ecol where we look at pairwise competition in the greenhouse and the field. Our study is more complicated in that we also consider genetic variation in competitive ability, but I think your class could ignore the genetic variation and do something like our "greenhouse experiment 1" (see methods), which would produce a figure like that attached in the pdf file, which clearly shows the dramatic effects of competition. Similarily, you could try to do something in the field like we did in the field experiment (ignoring genetic variation), and here again the effects of competition are pretty clear from figure 4. Good luck, Marc (mtj5@duke.edu) for those that would like Marc to e-mail them the papers. ----- Dear friend, I am developing these ideas for years and a good project is about plant competition!!! You can use species like carrots and radishes because they grow fast and you can compare variables like number os leaves, lenght of leaves, leaf dry weight, root lenght, root dry weight in plants growing alone and together with another species. Another student team can test the same using a very poor soil with sand or with less watering. You can use around 40 plastics glasses for each treatment and eliminate the glasses with seed not geminating. Good luck!!! Voltolini Prof. Dr. J. C. VOLTOLINI Grupo de Estudos em Ecologia de Mamiferos (ECOMAM) Universidade de Taubate - Departamento de Biologia Taubate, SP. 12030-010. E-Mail: jcvoltol@uol.com.br Website do ECOMAM: http://jcvoltol.sites.uol.com.br/ Fotos de Cursos: http://jcvoltol.fotoblog.uol.com.br/ Amostra de um Curso de Campo de Ecologia: http://trabiju.blogspot.com/ Currículo Lattes: http://lattes.cnpq.br/8137155809735635 Fotos Artísticas: http://voltolini.fotos.net.br/texturas aparmakel@biol.uoa.gr