Robo Alive Saharan Red Lurking Lizard Battery-Powered Robotic Toy by ZURU (Red)

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Lead author and USC Ph.D. candidate Johanna Schultz said that after four years of studying lizard movement, and multiple generations of robot designs (X-4 is just the most recent), the team concluded that lizards had practically perfected the way they moved for speed, stability and efficiency. Looking at the lizards’ phylogenetic trees showed that ancient terrestrial tetrapod linages, such as salamanders, exclusively use rotations in their spine to move, but modern climbing lineages move their limbs to extend their reach more. “Evolution was following the same gradient as our robot, moving towards this optimum,” says Clemente. As part of a larger study, Clark and colleagues investigated why it is that these differences in signals exist between the different species of lava lizard, in a paper published in Animal Behaviour. To do this, they designed robot lizards of two different ‘species’, Microlophus grayii and Microlophus indefatigabilis. The researchers used these robot lizards to simulate interactions between them and real lizards of the same two species. Therefore, a real lizard could either have an interaction with a robot of the same species, or of a different one. The idea here is, if different species have evolved to pay attention to each other’s signals (and thus avoid mating with a different species), then males that are the same species as the robot should respond much more to the robot’s signals than a lizard of the other species. On the other hand, if the different species arose by genetic drift, then we wouldn’t expect for there to have been as much selection on individuals to avoid mating with the other species. Over time, as these differences between the two different populations become larger and there is less and less mating between the populations, they will become ‘reproductively isolated’ (i.e. not mating with each other at all) and thus become two new species. The team then built a robot model to investigate the advantages of lizardlike and snakelike body movements in the intermediate lizard species. Known as a robophysical model, the robot functions as a physicist’s model of a living system that can also be used to vary parameters such as limb length and how the lizard’s body drags on the ground. With such capabilities, they can test the predictions of their theoretical model while also gaining understanding of the biological system.

Using geometric mechanics, Chong produced diagrams that visualized the body-limb coordination data, replacing complicated calculations with much simpler diagrammatic analysis. They were able to both see and show the advantage of snakelike waves in short-limbed elongate lizard locomotion and predict that the advantage arises as the primary thrust generation shifts from the limbs to the body.With the robophysical models, we can develop principles that can also inform the next generation of robots that might have to crawl around in rubble or move around in extraterrestrial environments like the surface of moons or planets,” Goldman said.

One set of animals where it is not clear how the differences between similar species arose is the lava lizard. Lava lizards live throughout the Galapagos archipelago and there are nine species in total. The different species are separated from each other geographically and have both different colouration and different push-up and head-bob behaviour that they use for communication. Research supervisor Dr. Christofer Clemente said there is potential for lizard-inspired robots to assist with operations such as remote inspections for electronics in remote locations — startup Eelume Subsea Intervention recently announced its own snake-like underwater maintenance robot in a similar vein.

Mimicking years of evolution to make climbing robots

Using biological experiments, robot models, and a geometric theory of locomotion from the 1980s, researchers at the Georgia Institute of Technology investigated how and why intermediate lizard species, with their elongated bodies and short limbs, might use their bodies to move. Led by living systems physics professor Daniel Goldman, the research team studied body-limb coordination in a diverse sample of lizard bodies. Their multidisciplinary approach uncovered the existence of a previously unknown spectrum of body movements in lizards, revealing a continuum of locomotion dynamics between lizardlike and snakelike movements. Their findings, published in the June issue of Proceedings of the National Academy of Sciences, deepen the understanding of evolution’s implications for locomotion, and have additional applications for advanced robotics designs. Baxi Chong, a Ph.D. student in Goldman’s lab and first author of the paper, became interested in the short-limbed, elongated lizard species Brachymeles at a presentation by Philip Bergmann, associate professor of evolutionary biology at Clark University, in which Bergmann discussed the evolution of the species. Chong, a theoretician, had a tool in mind that he believed could help explain how the rare lizard moved, so he reached out to Bergmann to collaborate. Bergmann sent footage of the lizards in the wild to Goldman’s lab for analysis. By understanding which parameters influence an animal's locomotion, we might be able to define what a robot would have to look like and how it would have to move depending on what we want the robot to do: be super-fast, super stable, or something in the middle," Ms. Schultz said. Anole lizard (Anolis cristatellus) in the Caribbean National Forest in Puerto Rico. Credit: Terry Ord/UC Davis

Ord and Stamps observed that "male lizards...advertise territory ownership to neighbors and intruders via dynamic visual displays consisting of species-typical headbobs and extensions of a colored dewlap." Sometimes, they begin their displays with exaggerated 4-legged push-ups before beginning the typical headbob sequence. Each of the hip joints connecting the spine structure with the robot's legs is made of two servos and a four-linkage mechanism that allows the robot to lift without losing its balance. The robot's "feet" have four flexible "toes," consisting of two hinges and a claw. Sometimes the robot lizards did the headbob thing without the push-ups. Sometimes they used push-ups before the headbob thing. Sometimes they did the dewlap thing before the headbob thing. Importantly, this particular species of lizard never uses the dewlap thing as an announcement (though other species do). The researchers included this condition to test the hypothesis that ANY high-speed movement at the beginning of a display could function as an announcement.Snakes and lizards have distinct body movement patterns. Lizards bend from side to side as they retract their legs to walk or run. Snakes, on the other hand, slither and undulate, like a wave that travels down the body. However, there are species of lizards that have long, snakelike bodies, and limbs so tiny even scientists have wondered about their purpose. Understanding how these hybrid-looking lizards move could provide insight into why an evolutionary transition from lizardlike to snakelike motion occurred. The orientation of their feet is not at all aligned with their direction of climbing," said Ms Schultz, who completed her undergraduate studies at the University of Bremen in Germany. The researchers initially evaluated their robot in a series of simulations, to determine whether it could effectively replicate the movements of lizards. Their results were very promising, as they found that their robot could perform the desired motions and walking style. Like the researchers, both Xu and Morin have also worked on bioinspired color-changing materials in the past, using divergent approaches to imitate what the live animals still do best. Researchers in the field are still long ways off, says Xu, and he’s constantly in awe of the physiologies of these actively camouflaging creatures.

The researchers found that, when more body weight was distributed on the belly rather than the limbs, snakelike body movement had the clear advantage in getting lizards where they need to be — even for those lizards with the strongest legs. These results would seem to imply that there had been selection on lizards to not mate with other, similar species. However, the researchers also carried out a phylogenetic analysis which showed that the lizards had evolved these traits in isolation from one another and without much effect of sexual selection. So what’s going on? It seems that the lizards have evolved the ability to pay attention to the different behavioural signals of each other (and discriminate against the ‘wrong’ species) without having evolved in the same geographic area as them. Exactly how this happens is still not clearand perhaps just shows more than anything that evolution is complicated!The Mars rover can't get to a lot of places it needs to go because it's on wheels, but a legged climbing robot could access these areas," he said. This fantastic kit has everything necessary to build your loveable reptilian, giving you the satisfaction of building your very own AI robot. This kit is a great project for adults and children alike, allowing you to create, build and play.