This model represents the exponential growth of a Quokka population. Quokka's are a small creature which are native to the Australian continent. This model's inflow are the joey's that enter the initial quokka population through each quokka mother that gives birth. This would be like the faucet turning on in the bathtub model which then adds to the stock. The initial quokka population is the stock according to the bathtub model as previously mentioned in this week's reading by Donella Meadows. The stock is what is already present. So the tub contains water, just like how the initial population of quokka's is present before the addition of baby quokka's, also known as joey's. Finally, the outflow, are the quokka's leaving the population by death. Similar to the bathtub model, this would be similar to the drain, removing the stock from the model. This whole system keeps the quokka population in equilibrium and can also act as a guide to sustainability, as it allows us to view birth and death rates of a population. We can then work with the numbers of this model to decide how we want to approach this population with sustainability in mind. For example, a high birth rate means we would need to find methods to control the population to create a sustainable environment which is able to maintain this population. Overall, this model can help look at population rates, while keeping sustainability in mind.