(a) The Paramecium population in the lab (graph a) appears to have a logistical population growth. Visually, the data and trend line of the graph create an S-shaped curve, which is the shape of a logistical population growth. A logistical population growth is a population growth that initially occurs at a constant rate of increase over time, but then levels out as the carrying capacity of the environment is approached. For 10 days the population increases at a steady rate. However, after day 10 the rate of population growth relatively decreases to zero at a carrying capacity of approximately 900 Paramecium/mL. A carrying capacity is the largest population a particular habitat can support and sustain for an indefinite period, assuming there are no changes in
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Also, since exponential population growths rarely occur in nature, they occur most often in a laboratory setting due to a lack of competitors and other forces that normally decrease populations. However, after day 60 the population steadily decreases below the carrying capacity and then stabilizes at a growth rate of zero on day 140. This change in growth rate was most likely cause by a limitation of resources that began after 60 days, thus causing the population to decrease and then stabilize at a new carrying capacity.
(c) While the song sparrow population (graph c) is a logistical population growth as well, the amount of sparrows vary greatly compared to the other graphs, primarily due to the fact that this population is in its natural habitat over the span of 25 years. While the populations in the laboratory setting had one carrying capacity, the sparrow population has several, all at different population amounts. This is due to the fact that, in nature, the carrying capacity changes in response to environmental changes. Also, this population experienced a few population crashes, an abrupt decline from a high to low population density. This is commonly caused by an exhaustion
Also, since exponential population growths rarely occur in nature, they occur most often in a laboratory setting due to a lack of competitors and other forces that normally decrease populations. However, after day 60 the population steadily decreases below the carrying capacity and then stabilizes at a growth rate of zero on day 140. This change in growth rate was most likely cause by a limitation of resources that began after 60 days, thus causing the population to decrease and then stabilize at a new carrying capacity.
(c) While the song sparrow population (graph c) is a logistical population growth as well, the amount of sparrows vary greatly compared to the other graphs, primarily due to the fact that this population is in its natural habitat over the span of 25 years. While the populations in the laboratory setting had one carrying capacity, the sparrow population has several, all at different population amounts. This is due to the fact that, in nature, the carrying capacity changes in response to environmental changes. Also, this population experienced a few population crashes, an abrupt decline from a high to low population density. This is commonly caused by an exhaustion