This sample essay on Predator Prey Lab provides important aspects of the issue and arguments for and against as well as the needed facts. Read on this essay’s introduction, body paragraphs, and conclusion.
An adaptation aids survival by either decreasing a prey’s chance of being eaten, or y increasing a predator’s chance of obtaining food to survive and reproduce. Predators must fight for food. They face density-independent factors which are factors that limit resources, but they cannot be controlled; an example would be bad weather or wildfires.
Density-dependent factors are things that can be controlled such as the amount of competition in an environment.
For example, if a preys traits allow it to run faster, the predator must also have the characteristics to allow it to run fast enough to catch its prey.
Many people confuse adoptions with evolution, but they are not the same. Adoptions are changes in an animal that happen in one generation, while evolution occurs over many generations (Modern Biology, 2006).
Charles Darwin had a theory that was the opposite of adaptations. Charles Darning’s theory of natural selection was basically “survival of the fittest. ” When organisms reproduce and exceed the carrying capacity, the competition in the environment increases. Because of this, some organisms will not survive (Theory of Natural Selection).
It was then that Darwin realized those organisms who were most suited for the environment were the ones who will live on and produce (Darning’s Theory of Evolution). For example, picture two birds in an environment. One bird has a long beak and the other has a short beak. The bird with the long beak is able to reach into the holes in the ground and eat the seeds, but the other cannot. The bird populations with the long beaks will be able to survive and reproduce while the population of birds with the short beaks will thin out and eventually go extinct (Modern Biology, 2006).
Problem: Which predators will be able to survive and reproduce based on their characteristics, adaptations to the environment, density-dependent factors such s competition for food, and density-independent factors such as bad weather or wild fires? Hypothesis: The spoon will be the predator that survives, reproduces, and dominates the population. If there is a competition between predators over a prey, then the spoon will easily be able to use its bowl-like shape to easily scoop up the prey. If the prey is hidden in the grass, then the spoon will be able to slide through the grass and scoop up any prey hiding.
Materials: . 300 pieces of corn 2. 300 pieces of black beans 3. 300 pieces of lima beans 4. 100 pieces of pinto beans 5. Plastic forks with one tongue removed (Broken Forks) . Plastic forks 7. Small plastic knives 8. Plastic spoons 9. Tweezers (forceps) 10. A grass field approximately 15 meters square or a carpeted area about the same size. 11. Styrofoam 6-8 oz. Cups 12. Stop watch Procedures: 1. Distribute 100 pieces of corn, lima beans, and black beans onto the field. 2. Divide the class into 5 groups that are as close to equal as possible. . Give each member of one group forks, of another group spoons, of another group broken forks, of another group knives, and the last group forceps. (If there are no forceps available, the lab can be demonstrated with only 4 groups. 4. Every student gets a Styrofoam cup. 5. Instruct the students that they are individual predators with structural variations. The beans and the corn are the prey. The prey must be picked up with the feeding mechanism (forks, knives, spoons, broken forks, and forceps) and placed in the model mouth (cup).
No scraping or pushing of the prey in the mouth is allowed – the cup may not touch the ground area. The predators may, however, dash in and pick up any prey being pursued by another predator. Do not hesitate to intrude, any hungry natural predator would not. Hunting time will be 5 minutes. When the teacher or the “wildfire” comes around and touches any of the students, they must step out of the playing area for fifteen seconds. When told to stop, each student will tally up his “kills”. If a predator is in the process of capturing a prey when told to stop, he must drop it. 6.
Repeat this process for each generation and make the proper adjustments required for each. 7. At the end of the lab, share your data with the class and add up the number of prey killed. Observations: In certain parts of the field, the grass was very tall and the prey that were in that area were very difficult to find. Because of this many predators ignored the grassy areas which caused a lot of competition for prey in the other areas of the field. Certain prey such as the corn was easily concealed in the grass because of its small size. However, in the dirt area, the color of the corn really made it stand out.
Therefore, the spoon population was able to reproduce while the other populations began to thin out because they were not as well adapted to the environment, and they were not able to reproduce. Their populations decreased steadily and we can infer that they will eventually go extinct. Fig. 5 shows predator consumption. This graph corresponds to the Predator Population graph. In both graphs the spoon population increases while the others decrease steadily. Again, this is because the spoons were well adapted to the environment and they were able to get more food and reproduce.
Another reason was the fact that when some predators “starved to death” or consumed fewer than five preys they became part of the spoon population. This was done to show how populations that cannot get enough food die off, and those who can continue to live and reproduce. It proves the theory of natural selection. Fig. 6 shows the population of prey. In all cases except for the lima beans, the populations increased. This is because the lima beans were the easiest prey to catch and all the redactors went after them in the first generation. Their population immediately decreased at a drastic level.
Because of this, no more lima beans were thrown on the field to show they were no longer able to reproduce. However, for the second generation, the black beans and the corn population increased by one- hundred. This is because there were enough of them left to reproduce. In the third generation you see the corn population increase by one-hundred once again. This is because they were able to reproduce again. However, the black bean population did not increase, but a pinto bean population started at one- hundred. This was because the pinto beans were an invasive species and took over the black bean population.
This caused the black beans to not be able to reproduce and their population size stayed the same. Conclusion: This lab was done to show how natural selection affects a predator-prey relationship. Only the strong and most adapted species can survive. The hypothesis was correct because the spoon population was the most adapted and over time became the dominate population. The spoon population was best adapted because it was able to easily scoop up and hiding prey and it was able to scoop up the prey easily in a competition. The spoons were the best adapted at capturing prey as well.
The knife and broken fork populations went extinct because they were not well adapted to the environment or catching prey. It can also be inferred that all but the spoon population will also go extinct because they are declining steadily. In human examples, men are able to adapt to the heat by air condition and water. They can adapt to the cold by wearing heavy clothing and heaters. There should be funding to continue to save certain species because there are many species that cannot fend for themselves, but they are incredibly important to the environment.
Letting natural selection wee out these species could cause great harm to humans and other animal. Reproduction allowed the spoon population to grow and dominate. It also allowed the corn survive and provide food for the predators. In this lab the experimental group was the predator and prey populations decreasing and increasing based on natural selection. The control variables was the area because it was not tested, as well as the time, and the fact that when you died you became part of the spoon population. The independent variables were the changes in population and prey consumption for each generation.