1 / 17

Evolutionary Effects of Size-Specific Selection in Guppy Populations

Explore the impact of size-specific selection on body size and life history traits in guppies through experimental design, data interpretation, and graphical representation. Evaluate evolutionary outcomes and fitness models in predator and predator-free environments.

daisy
Download Presentation

Evolutionary Effects of Size-Specific Selection in Guppy Populations

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Learning Goals • Content • Predict the effects of size-specific selection on body size and important life history traits (e.g. age at maturity) • Explain how selection on body size can result in the evolution of other characters (e.g. number of offspring) • Process • Graphically represent data and predictions • Interpret data from tables and graphs • Evaluate experimental design

  2. Vote for Best Cartoon • A) • B) • C) • D) • E)

  3. Checklist for scoring guppy experimental design • Fish transferred from an environment with predators to one without • There are two independent treatments (two different rivers) • Controls are the downstream habitats • Measure body size and reproductive traits in both environments: the treatments and the controls • Traits measured after 7-12 generations (or a period of time) • Values for the treatments and the controls in each river compared

  4. Treatments Move fish to predator-free environment Move fish to predator-free environment waterfall Controls El Cedro River Aripo River Guppy Predator 7 - 12 generations Compare Compare Control Treatment Control Treatment Size Time to maturity Time to maturity

  5. Vote for Best Graph • A) • B) • C) • D) • E)

  6. Rubric for scoring constructing a figure • Important results are easily gained from looking at the graph • Axes are appropriately labeled • Legend is appropriately labeled and the different values clearly differentiated • Important details (such as significance or information about treatments or controls included) • Figure or graph is not messy (straight lines, readable font, etc)

  7. 30 25 20 15 10 5 0 * Male Female Rate of Body Size Evolution (in Darwins) * * * * * ns Aripo (11 yrs) Cedro (4 yrs) Cedro (7.5 yrs) *—significant at 0.05

  8. Effect of Predation Transfer of fish from a locality with a predator to one without resulted in… • …an increase in average body size of the prey species • …a decrease in average body size of the prey species • …equivocal results because in some cases there was an increase in body size and in other cases there was a decrease in body

  9. A B Fitness Fitness Body Size Body Size Based on the results from the guppy experiment, choose the fitness model that best describes the environment with predators A) A B) B C) Both A and B describe the environment with predators depending on when you survey the population

  10. A B Fitness Fitness Body Size Body Size Based on the results from the guppy experiment, choose the fitness model that best describes the environment without predators A) A B) B C) Both A and B describe the environment with predators depending on when you survey the population

  11. Draw Your Prediction

  12. B A D C E) Some other graph not included above

  13. Draw Your Prediction

  14. Choose Your Graph A) B) C) D) E) My graph not shown

  15. The Data

More Related