Sigmoid growth curve define by

Options

A. Malthus
B. Adam Smith
C. Verhulst
D. Charles Darwin

Explanation

### Step-by-Step Solution:

1. **Understanding the Sigmoid Growth Curve**:
- The sigmoid growth curve is a graphical representation of population growth that shows how a population increases rapidly at first, then slows down as it approaches a certain limit, resulting in an S-shaped curve.

2. **Defining the Sigmoid Growth Curve**:
- The sigmoid growth curve is defined by logistic growth, which describes how populations grow in an environment with limited resources.

3. **Key Contributors**:
- The sigmoid growth curve was defined by several scientists, including Warholz and Perl. Their work contributed significantly to our understanding of logistic growth.

4. **Logistic Growth Equation**:
- The mathematical representation of logistic growth is given by the equation:
\[ \frac{dn}{dt} = r \cdot n \cdot \left( \frac{k - n}{k} \right) \]
- Where:
- \( n \) = population density at time \( t \)
- \( r \) = intrinsic rate of natural increase
- \( k \) = carrying capacity of the environment

5. **Interpreting the Variables**:
- \( \frac{dn}{dt} \): This represents the change in population size over time.
- \( r \): This is the rate at which the population grows when resources are unlimited.
- \( k \): This is the maximum population size that the environment can sustain.

6. **Conclusion**:
- The sigmoid growth curve is fundamentally linked to logistic growth, and it is characterized by its S-shape due to the initial exponential growth followed by a slowdown as the population reaches its carrying capacity.