Why do insects have six legs

Get a free answer to a quick problem. Most questions answered within 4 hours. Choose an expert and meet online. No packages or subscriptions, pay only for the time you need. Anatomy Zoology Evolution Entomology. Apparently, there is an advantage to having 6 legs in the insect world. Colloquially, in the terrestrial world, they are things that an organism walks on. But the scientific definition of 'legs', for insects, relies on homology: many insects have six 'legs' because they all descend from a common ancestor, which had six legs.

The anatomical structures derived from those legs, regardless of whether they are functionally used as paddles, or as claws, or as feeding appendages or elaborate mate-signalling devices, all get called 'legs'. Referring to all of these as 'legs' makes as much sense, from a functional perspective, as referring to our arms as 'legs'.

We only do it to keep the homology clear when talking about evolutionary relationships between species. The diversity of uses to which insects put their legs makes it clear that there is no single universal advantage of having six - it is just that completely losing or gaining appendages is a difficult evolutionary process, so it seldom happens over evolutionary time. Regardless, some groups of insects members of the Coccidae and Diaspididae , for instance have lost their legs completely - an apparent adaptation to their obligate parasitic lifestyle.

If it's an advantage either way, why don't bigger life forms like mammals have 6 limbs? In the insect groups which use six legs for locomotion, AliceD's answer provides an excellent description of how all six legs are used. However, there really is nothing special which can be achieved with six legs, which could not be achieved with some other number of legs: mantises handle their locomotion perfectly fine on just four of their six legs, and arachnids not insects, I know - but with many of the same design challenges such as a rigid exoskeleton manage equally fine on eight.

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Create a free Team What is Teams? Learn more. Why do adult insects have 6 legs? Ask Question. Asked 6 years, 1 month ago. Active 4 years, 2 months ago. Viewed 10k times. Improve this question. DrZ DrZ 1, 1 1 gold badge 11 11 silver badges 17 17 bronze badges. Many features of modern life-forms aren't necessarily 'better' than other possible features, but are the way they are as a result of historical chance and the constraints imposed by development.

Inclusive of applicable taxes VAT. By Jeff Hecht THE idea that all six-legged animals are insects has been turned on its head, along with the theory that all such creatures evolved from a common ancestor. Insects, springtails …. Arthropods are members of the taxonomic phylum Arthropoda, which includes insects, arachnids, and crustaceans. Insects represent about 90 percent of all life forms on earth.

More than one million insect species have been identified throughout the world, and some entomologists scientists that study insects estimate there may be as many as 10 million species. These species are divided into 32 groups called orders, and beetles make up the largest group. No one knows exactly how many insects are found within Everglades National Park.

Entomologists have prepared lists of some insect groups, such as bees, ants, and butterflies , but no park-wide inventory has been carried out yet. Insects have six legs and two antennae, and their body is made up of three main regions: head, thorax, and abdomen.

They have an exoskeleton that contains sense organs for sensing light, sound, temperature, wind pressure, and smell. Insects typically have four separate life stages: egg, larvae or nymph, pupa, and adult. Insects are cold blooded and do not have lungs, but many insects can fly and most have compound eyes. Insects are incredibly adaptable creatures and have evolved to live successfully in most environments on earth, including deserts and even the Antarctic. The only place where insects are not commonly found is in the oceans.

Insects pollinate flowers and crops and produce honey, wax, silk, and other products. However, some species that bite, sting, destroy crops, and carry disease may be considered pests to people and animals.