Metamorphosis – The Science of Change: Metamorphosis seems like the ultimate evolutionary magic trick, the amazing transformation of one creature into a totally different being: one life, two bodies.
From Ovid and Kafka to X-Men, tales of metamorphosis richly permeate human culture. The myth of transformation is so common that it seems almost preprogrammed into our imagination. But is the scientific fact of metamorphosis just as strange as fiction or… even stranger? Film-maker David Malone explores the science behind metamorphosis. How does it happen and why? And might it even, in some way, happen to us?
Metamorphosis – The Science of Change
Metamorphosis is a biological process by which an animal physically develops after birth or hatching, involving a conspicuous and relatively abrupt change in the animal’s body structure through cell growth and differentiation. Some insects, fishes, amphibians, mollusks, crustaceans, cnidarians, echinoderms, and tunicates undergo metamorphosis, which is often accompanied by a change of nutrition source or behavior. Animals can be divided into species that undergo complete metamorphosis (“holometaboly”), incomplete metamorphosis (“hemimetaboly”), or no metamorphosis (“ametaboly”).
Scientific usage of the term is technically precise, and it is not applied to general aspects of cell growth, including rapid growth spurts. References to “metamorphosis” in mammals are imprecise and only colloquial, but historically idealist ideas of transformation and monadology, as in Goethe’s Metamorphosis of Plants, have influenced the development of ideas of evolution.
All three categories of metamorphosis can be found in the diversity of insects, including no metamorphosis (“ametaboly”), incomplete or partial metamorphosis (“hemimetaboly”), and complete metamorphosis (“holometaboly”). While ametabolous insects show very little difference between larval and adult forms (also known as “direct development”), both hemimetabolous and holometabolous insects have significant morphological and behavioral differences between larval and adult forms, the most significant being the inclusion, in holometabolus organisms, of a pupal or resting stage between the larval and adult forms.