prompter: Why don't animals have wheels? Answer as briefly as possible.

assistant: Several organisms are capable of rolling locomotion. However, true wheels and propellers—despite their utility in human vehicles—do not seem to play a significant role in the movement of living things. First, there are several developmental and evolutionary obstacles to the advent of a wheel by natural selection. Secondly, wheels are often at a competitive disadvantage when compared with other means of propulsion.

prompter: That doesn't sound right.

prompter: Why is it difficult for wheels to occur naturally in animals? What are those evolutionary obstacles?

assistant: Wheels are a highly specialized and complex structure, and as such, it is highly unlikely that they would have evolved naturally in animals. Evolution of wheels would require development of a special skeletal structure and joints capable of supporting an animal's weight and allowing it to rotate muscles and tendons to drive wheel rotation, probably at a considerable cost in terms of survival and reproduction. Lastly, the wheel is a human invention, very useful in some circumstances, but the result of human ingenuity and technology rather than natural development.

assistant: There would need to be a way to bring in nutrients and get ride to the wheel body part. The wheel would spin and not be able to move resources and waste around.

prompter: For the organisms that are capable of rolling locomotion, how do they move that way without wheels?

assistant: Organisms that are capable of rolling locomotion use different mechanisms to roll without wheels. Some examples include:

Ball-rolling animals: Some animals, such as the pill millipede, roll into a tight ball as a defense mechanism.
Armadillo-like animals: Some animals, such as the armadillo, can roll into a tight ball for protection.
Rolling fish: Some fish, such as the barreleye, can roll their eyes to change the direction of their gaze.
Rolling insects: Some insects, such as the dung beetle, can roll a ball of dung using their legs.
In summary, organisms that are capable of rolling locomotion use a variety of mechanisms such as ball-rolling, armadillo-like rolling, rolling eyes and legs to move without wheels.

assistant: Several species of elongate organisms form their bodies into a loop to roll. Other species adopt more spherical postures, primarily to protect their bodies from predators. Species may roll passively (under the influence of gravity or wind) or actively, typically by altering their shape to generate a propulsive force.

assistant: Organisms capable of rolling locomotion typically achieve this by using their body shape and muscle contractions to roll themselves along a surface. For example, a pill bug, also known as a rollie-pollie, can roll into a tight ball as a defence mechanism. The pill bug's exoskeleton provides a hard exterior to protect its body while it rolls. Similarly, some caterpillars use their flexible bodies to roll themselves into a tight ball as a defence mechanism. Other organisms, such as certain snakes, can use their flexible bodies and muscle contractions to "inch" themselves along in a rolling motion.

assistant: Some organisms use rolling as a means of locomotion. These examples do not constitute the use of a wheel, as the organism rotates as a whole, rather than employing separate parts which rotate independently

prompter: It seems like legs would use a lot more energy than wheels, especially to balance. Why don't the energy savings of using wheels outweigh the disadvantages of them in biological creatures?

prompter: Well, what about prosthesis used in animal hospitals for animals with legs problems?

assistant: It is unlikely to happen by genetical mutations.

prompter: Elaborate pls

assistant: Animals do not have wheels because they have evolved to move in different ways that are better suited to their environments and survival needs. For example, animals that live in forests and rough terrain often have four legs that allow them to walk on uneven ground and climb trees. Animals that live in water often have fins or flippers that allow them to swim efficiently. Additionally, wheels are a man-made invention and don't occur naturally in the animal kingdom, in the same way, it doesn't occur in the plant kingdom either. Evolutionary pressure has led to the development of different forms of movement and structures, such as legs, fins, wings, etc. that are better suited to the environments in which different species live.

assistant: Evolution happens gradually, so a change has to be beneficial every step of the way, e.g. a slight increase in running speed or a more optimized gut flora. Wheels, on the other hand, need to be nearly perfect to provide any sort of advantage, unlike e.g. limbs, which allow for at least some locomotion even if barely formed.

assistant: There would be a big amount of mutation to represent anything like wheels in an animal and mutations are not that common to happen, so it would be unlikely to see that combination.

prompter: Could you elaborate on why is unlikely? Could you give me the answer as a list of bullet points?

prompter: Is it possible to create experiments to grow wheels on animals instead of legs?

assistant: It’s not fundamentally impossible to have wheeled creatures, but there are a number of different answers. The technical problem with making a biological wheel is blood supply. If you want to have a wheel, somehow you need to connect it up to the blood, and that’s an extremely hard engineering problem. You also need to provide some method of propulsion, although that could be done like a scooter, using other limbs to propel you along.

assistant: It's probably not impossible, but it might be extremely challenging. First, experiments involving biological evolution span over many generations of the organisms that are studied, which for most animals can last from weeks up to many years. Second, evolution by mutation and natural selection typically only makes small, incremental modifications to existing structures. Therefore, modifying legs, which are attached by joints, into wheels, which need a free rotating axle, might be very unlikely to happen.

assistant: Experiments to grow wheels on animals instead of legs can certainly be conducted, but it is unlikely to yield the desired outcome since wheels are a man-made object.

prompter: Please eloborate on why evolution will likely be unable to come up with an animal with wheels

assistant: Mechanistically because wheels are a human invention, and only a few animals have been invented by human. In general current modern technology is quite bad mergine biological and mechanical components in a way that is consistent with the animal's fitness curve. If by having wheels you mean only figuratevely, then domestic animals often have prostetic wheels as a consequence of surgeries and congenital problems which serverly impair their deambulation ability.

prompter: Oh, that's sad. On another note, there were animals invented by humans?

assistant: Oops! I was wrong earlier: No animals have been invented by humans. Humans have definitely modified animals through selective breeding and genetic engineering, but these actions hardly amount to something like inventing, which typically implies designing and creating product from the ground-up.

assistant: Humans did not invent animals, except in their name. However there exists variantions in races in specific species that humans invented, such as dobermanns in dogs.

assistant: There man made hybrids such as mules which are deliberately bred. Also species that have been domesticated have their characteristics altered through humans doing artificial selection, an example of this are dog breeds.

prompter: Why did evolution never come up with wheels instead of legs?