Allometry is the study of the relationship of body size to shape. In particular, it refers to the rate of growth of one part of the body compared to other parts.
In most cases, the relative size of body parts changes as the body grows. Most allometric relationships are adaptive. For example, organs which depend on their surface area (such as the intestine) grow faster as the body weight increases.
Also, there are changes in allometry as a clade evolves. Allometry is an important way to describe changes in gross morphology (body shape) during evolution. Changes in time of development in an evolutionary series or clade are very common. The trend is known as heterochrony.
Allometry was first outlined by Otto Snell in 1892, D'Arcy Thompson in 1917, and Julian Huxley in 1932. The relationship between two measured quantities is often expressed as a power law:
or in a logarithmic form:
where is the scaling exponent of the law.
Questions and Answers
Q: What is allometry?
A: Allometry is the study of the relationship of body size to shape, and refers to the rate of growth of one part of the body compared to other parts.
Q: How do most allometric relationships change as a body grows?
A: In most cases, the relative size of body parts changes as the body grows.
Q: What are some examples of adaptive allometric relationships?
A: Organs which depend on their surface area (such as the intestine) grow faster as the body weight increases.
Q: Who first outlined allometry?
A: Allometry was first outlined by Otto Snell in 1892, D'Arcy Thompson in 1917, and Julian Huxley in 1932.
Q: How is a relationship between two measured quantities often expressed?
A: The relationship between two measured quantities is often expressed as a power law or logarithmic form.
Q: What does "a" represent in this equation? y = kx^a + logk A: In this equation, "a" represents the scaling exponent of the law.
