Student Article
Student Article: Why Some Creatures Transform
Bilateral symmetry (noun): A type of body arrangement where an organism's left and right sides are mirror images of each other.
Radial symmetry (noun): A type of body arrangement where an organism's parts are arranged around a central point, like spokes on a wheel.
Exoskeleton (noun): A hard outer structure that provides protection and support for some animals.
Embryo (noun): A very young organism in the early stages of development.
Ecological niche (noun): The role and position an organism has in its environment.
Metamorphosis is a fascinating process where animals undergo dramatic changes in form. We first encounter this through stories like "The Very Hungry Caterpillar," where a caterpillar turns into a butterfly. This transformation creates significant differences between larvae and adults.
What animals go through metamorphosis?
Metamorphosis is common in insects and amphibians. Flatfish, for example, start with bilateral symmetry but change as they grow, with one eye moving to the other side of their body. Similar phenomena occur in invertebrates like echinoderms, where larvae are bilaterally symmetrical but adults have radial symmetry.
Do insects go through metamorphosis?
Insects like butterflies, beetles, and dragonflies undergo metamorphosis. They start as larvae, such as caterpillars, and transform into adults with wings. Primitive insects like silverfish do not change much and look like small adults when they hatch. More advanced insects, like crickets and dragonflies, undergo partial metamorphosis, while most insects, including beetles and flies, undergo complete metamorphosis.
What about amphibians?
Frogs and salamanders are amphibians that undergo metamorphosis. Frogs start as tadpoles with gills and tails. As they grow, they develop lungs and legs, and their tails disappear. Salamanders also change from having tails for swimming to having legs for walking on land. The axolotl is an unusual species that retains larval traits even as an adult.
How does metamorphosis work?
Metamorphosis involves the remodeling of an animal's body through cell changes controlled by hormones. Insects shed their exoskeleton to grow, while amphibians change their body parts to adapt to life on land. The process is technically defined as the transitions that occur after an embryo has finished developing.
Why is metamorphosis important?
Metamorphosis allows animals to occupy different ecological niches at different life stages, reducing competition for resources. For example, tadpoles are herbivores, while adult frogs are carnivores. This process helps them survive and thrive in various environments. The evolution of powered flight in insects likely contributed to their success and diversity, enabling them to find food, escape predators, and move to favorable climates.
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Bilateral symmetry (noun): A type of body arrangement where an organism's left and right sides are mirror images of each other.
Radial symmetry (noun): A type of body arrangement where an organism's parts are arranged around a central point, like spokes on a wheel.
Exoskeleton (noun): A hard outer structure that provides protection and support for some animals.
Embryo (noun): A very young organism in the early stages of development.
Ecological niche (noun): The role and position an organism has in its environment.