Question

A biologist surveyed islands of different sizes and consolidated the results in the form of the data given below. Study the data carefully and answer the questions that follow.

Name of Islands	Island Area (sq. km)	No. of mammalian species
P	1	5
Q	10	18
R	100	60
S	1000	150

1. What pattern do you observe in the above data?
2. Name the scientist who proposed the concept of relationship between area and species.
3. Write the mathematical expression for this relationship.

Answer 1

(i) The data show a Species–Area Relationship: as the area of the island increases, the species richness (number of mammalian species) also increases, following a consistent pattern.

(ii) Alexander von Humboldt

(iii) The species-area relationship follows a power function.

log S = log C + Z log A

Where:
S = Species richness
A = Area
Z = Slope of the line (regression coefficient), typically 0.1 to 0.2
C = Y-intercept (a constant)