Natural Selection lab
This is a Natural Selection lab that we normally run in BIOL 1001 lab. Since we are no longer face-to-face this semester, the videos/ virtual lab/ data will be provided to you. This assignment will make you familiar with what we normally do for this lab. Please read the instructions and complete the assignments. The due date for this assignment is July 09, 2020. Remember to submit your assignments electronically through D2L.
THE CHIPS ARE DOWN: A NATURAL SELECTION SIMULATION
Introduction The process of natural selection occurs because organisms vary in their heritable characteristics, and some variants survive and reproduce better than others. As a result, the genetic structure of a population changes through time. Natural selection occurs via the interaction of the environment and organisms (including the organism’s components).
It is far too time-consuming in our lab period to observe natural selection at work in natural populations, so we will use artificial populations consisting of chips. These chips (prey) will be removed from the population (‘eaten’) by you (predator). You will use your vision to find the prey and ‘eat’ them (i.e. remove them and their genes for color from the population). Note: Don’t really eat the chips, really.
Definition of evolution a. Descent with modification, the idea that living species are descendants of ancestral species b. Genetic changes in a population from generation to generation
The process of natural selection 1. variations exist within a population 2. more offspring are produced than survive 3. competition for resources occurs 4. some individuals have characteristics that allow them to survive and reproduce more than others (fitness) 5. these traits are passed on to offspring 6. over time a population will change to reflect the selected traits
Simulation Procedure:
- 1.On the table tope, spreadout the fabric or paper habitat given to you by your teacher on the table t
- 2.Countout 25 chips of each of the 4 colors for a total of 100 as your initial populati
- 3.Appointone person as the prey (chip) distributor. That person should spread the chips out randomly over the entire fabric, making sure the chips do not stick togeth The other members of the group should have their backs turned during this procedure.
- 4.Thepredators (other members) should turn around and take turns picking off the prey (chips) one by one until only 25% remain. COUNT CAREFULLY. Predators are to take the first chip they see and follow each chip to the discard area with their eyes so as not to see more chips, and keep track of the number of chips they ge
- 5.Carefullyshake off the fabric to remove survivors (remaining 25 chips).
- 6.Groupthe survivors according to Count and record these numbers.
- 7.Assumeeach survivor produces three offspring. Using the reserve chips, place three chips of the same color with the survivors (e., take the number of survivors multiplied by 4).
- 8.Mixthese chips together and re-distribute them as in step
- 9.Repeatthe entire process two more times, making a total of three generations of prey being preyed
CHIPS ARE DOWN….Data Sheet
PURPOSE:
| COLORS | |||||
| Color 1 | Color 2 | Color 3 | Color 4 | ||
| Number at start–> | 25 | 25 | 25 | 25 | 100 |
| # after 1st predation–> | 3 | 15 | 5 | 2 | 25 |
| # after 1st reproduction–> | 12 | 60 | 20 | 8 | 100 |
| # after 2nd predation–> | 2 | 18 | 4 | 1 | 25 |
| # after 2nd reproduction–> | 8 | 72 | 16 | 4 | 100 |
| # after 3rd predation–> | 1 | 21 | 3 | 0 | 25 |
REVIEW QUESTIONS:
- Compare the original and survivor populations. Is there any color from the original population that is not represented in the final survivor population? If so, what color?
Yes, color 4
- Compare the original and survivor populations. Is there any color from the original population that is dominant (most represented) in the final survivor population? If so, what color?
Yes, color 2
- How are the colors of the survivors related to their habitat?
The colors of survivors represent their adaptation to their habitat. Color 1 slightly adopted and only survived one, color 2 adapted to the habitat they survived 21 of them, color 3 survived only 3 of them and color 4 did not survive, and they were phased out. Color I and 3 have a lower survival chance, and any slight alteration could lead to their extinction.
- What would happen if you switched fabrics (changed the ‘habitat’)? Would your results change? Explain.
Changing habitat would mean that the chips would be in a totally new environment, and they would need to adapt to it, and those that cannot adapt will be phased out.
- Using Microsoft Excel, create a line graph from the data below. Label the x-axis ‘Reproduction Period’ and the y-axis ‘Number of Prey Organisms’. The line graph should have four lines (black, blue, red and yellow). Insert your completed Excel line graph into this Word document. YouTube ‘how to make a line graph in Excel’ for assistance if needed.
Data to graph (taken from the Data Table above)
| Red | Black | Blue | Yellow | |
| Reproduction Period 1 | 12 | 60 | 20 | 8 |
| Reproduction Period 2 | 8 | 72 | 16 | 4 |
| Reproduction Period 3 | 4 | 84 | 12 | 0 |
The Making of the Fittest: Natural Selection and Adaptation video Using this link, https://www.biointeractive.org/classroom-resources/making-fittest-natural- selection-and-adaptation, watch The Making of the Fittest: Natural Selection and Adaptation short film and answer the following questions.
- Where does this study take place?
√a. desert b. coastal zone c. rainforest d. tundra
- What is the major predator of interest in this system?
- snakes √b. birds c. scorpions d. feral cats
- The ground of this environment is normally __________ colored, however a lava flow that occurred about 1,000 years ago covered portions of the area with ________________ colored rock. √a. light, dark b. dark, light c. medium, light d. medium, dark
- Predators of the rock pocket mouse mostly hunt via
- smell √b. vision c. hearing d. touch
- This film is about natural selection. What is acting as the selective force?
- mice √b. the environment c. predators d. prey
- Most rock pocket mice are light colored, occasionally
a dark colored mouse will be born. The dark color appears because of a. genetic drift
√b. mutation
- predation
- natural selection
- A light colored mouse will try to avoid the lava flow rock.
√a. true b. false
- Coat color in rock pocket mice is controlled by ___________ gene(s)
- one b. two √c. many d. zero
- Dark coat color in the rock pocket mouse spreads quickly through the population of mice living on the lava flow. This is because mice that happen to have dark coats are more likely to
- find food √b. survive and reproduce c. find water d. come out only at night
- Evolution is not ‘goal oriented’ it is not trying to make the perfect mouse. What would happen if a dark colored mouse was born into a population of mice living on the sand?
- the dark colored mouse would be more likely to survive than a light colored mouse
- the dark colored mouse would be less likely to survive than a light colored mouse
√c. the dark colored mouse would be as likely to survive as a light colored mouse
- Is evolution via natural selection a random process?
- yes √b. no
- The researcher in this video sampled several lava flows that were separated by hundreds of miles. He found only dark mice on each of these lava flows. Upon further investigation, the researcher discovered that the mice from the different lava flows were dark due to the same mutation in each of their genes.
√a. true b. false