We don’t think there would have been any selection pressure to keep a dark fur mutation around for there to be any dark mice before the lava flow.
This indicates the dark mutation was already present in the population. One thing that bothered us is that the first picture showing location B BEFORE the lava flow has one dark mouse.
We counted our mice and then put the illustrations in order. –This activity had you look through some pictures depicting rock pocket mice in two locations over time (mixed up). Second activity: Color Variation Over Time in Rock Pocket Mouse Populations Evolution helps us to understand the history of life. This definition encompasses small-scale evolution (changes in gene frequency in a population from one generation to the next) and large-scale evolution (the descent of different species from a common ancestor over many generations). You should work towards understanding all of the terms on this page: īiological evolution, simply put, is descent with modification. This activity provides an introduction to natural selection and the role of genetic variation by asking students to analyze illustrations of rock pocket. This was a good time for Jack to pull out his textbook, but another alternative that is an excellent source of information on evolution is the Berkeley Paleontology’s website on evolution: Here are some good starting points: Gene flow may introduce beneficial alleles into different populations experiencing similar selective pressures.Īnd that is when we realized we needed to pay more attention to question #4: the other mechanisms. Also, if spans of rocky outcrops are between the lava flows, then these habitats would provide suitable locations for migrating dark mice to “hide” in during the migration in order to avoid predators. If the lava flows were indeed close to one another, rock pocket mice may be able to migrate from one population to another. The “official” answer is: Gene flow (migration) could be the mechanism in the described scenario. There would be breeding between all the populations, right? Once the mutation has happened, natural selection would keep the frequency of the dark fur gene higher in the mice living on the lava, and vice versa for the light mice on the sand. The question is: If two of the lava flows in New Mexico were near each other and included spans of rocky outcrops between them, what would be a possible mechanism, other than new mutations, to drive the decrease in the light coat-color gene frequency and the increase in the dark coat-color gene frequency in these rock pocket mouse populations? Explain your answer. Question #5 actually confused us, since we weren’t sure exactly what they were looking for. The Teacher’s handout has the “answers” so you can check your answers (link to HMMI page: ).
ROCK POCKET MOUSE ACTIVITY HOW TO
The answers might seem simple and obvious, but it is about learning how to use the language of biology when discussing selection, fitness, and so on. Jack answered orally, but will be writing most of these down. There are also some great questions to answer. We filled in the amino acids for the different mice populations we’ll learn lots more about all of this later on in genetics.
There’s also a short film that shows two scientists who have been working with these mice in New Mexico for years now – it is only 10 minutes, so well worth watching (direct link: ). There’s a short excerpt from Smithsonian (here’s the link to the entire article: ).
First one: Natural Selection and Evolution of Rock Pocket Mouse Populations. We started with the two rock pocket mouse activities. (HMMI Biointeractive activity – analyzing data and answering questions)Ĭolor Variation Over Time in Rock Pocket Mouse Populations (more in same vein – analyzing data and answering questions)Īllele and Phenotype Frequencies in Rock Pocket Mouse Populations – an introduction to Hardy Weinberg What we did/More information Throughout the activity, students learn concepts such as fitness, natural selection, mutation, and phenotype.Natural Selection and Evolution of Rock Pocket Mouse Populations. Students then watch the HHMI Video on pocket mice and answer discussion questions. Students also graph the color differences at each location to show how the dark variation increased over time in response to an environmental change. (Cards can be printed and laminated for multiple uses.) Students collect data on the number of mice phenotypes in each location and develop a hypothesis about the order of the cards. Students look at cards showing light and dark mice on different substrates. It has been simplified from the original activity so that it is suitable for beginner biology students. This worksheet was modified from the HHMI Activity on color variation in the rock pocket mouse.
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