Lajien välinen
kilpailu
ja evoluutio
|
Interspecific Competition lesson This lesson will demonstrate how competition can affect ecosystems. Competition is an interaction between individuals or species, in which one is harmed when both are trying to use the same limited resource for growth and reproduction. Competition happens when the ecological niches of two species overlap and when the demand for the resources is greater than supply. Each species has its own ecological niche in the community, that is a sum of a species´ use of the biotic and abiotic resources in its environment. In our game, we demonstrate the effects of an exploitative competition, where two species compete indirectly for the same limited resource. This can impact species survival and reproduction and thus lead to changes in the species composition in a community. To understand it better, participants will play an interspecific competition game using two scenarios: no competition and with competition. – – – – – – – – – |
|
Keywords:
interspecific competition, species interactions, ecological niche, Gause´s law. Lesson plan: Competition lesson takes around 45 minutes. It consists of 10 minutes of introduction to the topic, 25 minutes of the game and finally 10 minutes of discussion and going through some examples. Save extra 20 minutes if you want to draw the graphs for competition and no-competition scenarios. You can also use the ready-made excel sheet to demonstrate how number of individuals changes in time in different scenarios. – – – – – – – – – |
|
Equipment needed for the game:
– – – – – – – – –
Participants will first play no competition scenario, in which there are enough resources, that allow all the viable population to grow. This allows them to experience what happens in no competition environment and understand the effects of the competition. Moreover, resources in nature are often limited. Thus, participants will also play 3-5 rounds of the game under competition scenario. After the game you can discuss how these two scenarios differed and why? See more post-activity questions below. To set up the game: 1. Distribute balls randomly on a table (see the equipment needed for the game). 2. Divide participants into 3 person groups. 3. Give all the participants an animal card (different species each within a group) and spoon / 2 forks / 2 knives to collect the balls, a plate and 3 life chips. 4. Explain the rules. Rules: 1. Each animal has to collect balls, in order to survive and reproduce in the game. 2. Each animal has its own eating habits. For example, red fox can collect green, orange and blue balls. Wolf can collect white and orange balls. Lynx can collect yellow and blue balls. 3. Each animal has its own adaptations to collect the food: one spoon (fox), two forks (wolf) and two knives (lynx). Note, tools can be held in ONE hand only. 4. Participants have 30 seconds in each round to collect the balls. 5. Each animal starts the game with three lives (3 life badges). In order to survive the round, each species needs to collect at least 5 balls. If the participant collects 3 balls beyond the 5, then they will get an additional life chip, showing that they have successfully reproduced! 6. The game will last min 6 rounds (3-no competition, 3-competition) and each round will last 30 seconds. – – – – – – – – – Competition Game plan: Participants are divided into 3-person groups. These participants are divided so that all of them will get a different species card. So that each species has its own ecological niche. Players will play 3-4 first rounds a no competition scenario, and then the same game where there is limited amount of resources. The aim of the game is to survive and try to produce offspring under both scenarios. Each species can collect only certain coloured balls (i.e. have their own ecological niches). These resources can be collected using a certain tool (i.e. spoon/two forks/two knives). Tools can be held in one hand only. In the beginning of the game each participant will start off with 3 life chips. In order to survive the round, each species needs to collect at least 5 balls. If the participant collects 3 balls beyond the 5, then they will get an additional life chip, showing that they have successfully reproduced! The game will last several rounds and each round is 30 seconds long. The first 3 rounds are played in no competition environment. After that some balls will be removed and the participants play the same game in the competitive environment then the game will continue for 3 more rounds. Post-activity questions for the students: * Compare the game in the no competition environment and competitive environment. * What happens in the no competition environment? * What happens in the competitive environment? * Why? * What affects competition? * What happens if niches overlap completely? What happens if the niches do not overlap? – – – – – – – – – |
