The Surging News reporter Xue Shasha intern Wang Schuman
With a pink nose, small eyes, wide and flexible ears, and a tail that resembles a broom, the pigtail rat, known as the "blind mouse", has its own echo localization ability.
Recently, researchers from the Kunming Institute of Zoology of the Chinese Academy of Sciences came to this conclusion.
The Shi Peng Research Group, Jiang Xuelong Research Group and Liu Zhen Research Group of the State Key Laboratory of Genetic Resources and Evolution of the Institute jointly tackled the problem and confirmed the echo localization ability of species of rodent-tailed rat genus by integrating multiple independent evidences of behavioral, anatomical, genomics, and gene function experiments.
"In addition to the well-known bats, toothed whales, etc. with this ability, pigtail rats also have this ability, which is very magical in itself!" On July 5, Dr. Liu Qi, one of the researchers and one of the researchers in Shi Peng's research group, said in an interview with the surging news (www.thepaper.cn) that the research on the echo localization ability of pigtail rats lasted for about 4 years. This research is expected to make the pigtail rat a new experimental animal for studying vocalization, hearing, echolocation neural circuits and other aspects. He also hopes that the results of the research can be applied to artificial intelligence in the future, such as improving autopilot driving in cars and assisted navigation for the blind.
"Are there other mammals that have this ability but haven't been discovered?" Liu Qi believes that there is still a lot of room for human research and application of echolocation, and the study of pig tail rats is just the beginning.
The experiment lasted for nearly 4 years, and the researchers followed the pigtail rat to "stay up late"
The nose is pink, the eyes are small, the ears are broad and very flexible, and it swings back and forth like a bat, collecting sounds in different directions. Its tail is long, broom-shaped, and it has a pinch of white hair at the end of its tail.
This is Liu Qi's research object, the pigtail rat, because of its small eyes and is also known as the "blind mouse", it belongs to the rodent family Officinalis pigtail rat genus.
00:32
Video loading...
Pigtail Mouse Video Source: Interviewee (00:32)
Liu Qi studied the echo localization ability of pigtail rats. Echolocation refers to a directional behavior in which animals carry out activities such as navigation and foraging by comparing the differences in information between sound waves emitted and echoes received.
As early as 2017, Liu Qi had already begun to carry out this research.
At that time, after he did some basic work, the experiment had preliminary research results. He compiled the contents of the experiment into an English manuscript and sent it to the journal Secience in a short article. The journals have given a lot of recognition and interest in this research result, which gives them a lot of confidence.
"In the later process, we supplemented many experiments according to the requirements of the journal, and constantly enriched and improved the paper." Liu Qi said that on the one hand, it is necessary to get accurate experimental evidence in many aspects, on the other hand, the workload of each experiment is very large, including many revisions in the later papers, so the entire topic involves a relatively long time, and it is a joint research team of multiple research teams.
Liu Qi introduced that the corresponding authors of the paper, Shi Peng and Liu Zhen, have long been engaged in the research of convergence evolution and molecular genetic mechanism of echolocation, and have published many heavyweight research results. Another collaborative team, researcher Jiang Xuelong, who is also the corresponding author of the paper, is engaged in the research of the behavioral ecology and phylogenetic development and classification of pigtail rats. This research is the result of a joint research by three research groups.
Although there are 3 elite teams working together to conduct experiments, there are also many difficulties encountered in the experiments.
Liu Qi introduced that the first difficulty comes from the research object - pig tail rat. Before the study, they didn't know much about the wildlife's habits, such as what it ate, where it lived, whether it lived in groups, what the nest looked like, and how long it was active.
Secondly, the number of pigtail rats in the wild is not large, and using it to do experiments, there is a big problem is how to catch it, and catch a certain number of live pigtail rats.
At the same time, the researchers have no breeding experience, after catching a certain number of pig tail rats, they do not know how to raise, very worried about the artificially created conditions, can not make the pig tail rats show natural behavior.
However, as the experiment advanced, these difficulties found solutions.
What makes Liu Qi very interesting is that in the experiment, they found that animals such as pigtail rats are nocturnal, sleeping during the day and more active at night. Therefore, during behavioral experiments, researchers schedule experiments at night, sometimes having to work all night to complete an experiment.
Echolocation function of the small eye "blind mouse"
Liu Qi said that in the experiment, they recorded that the pigtail rat regularly emitted short-range, FM-type, high-frequency sound waves (peak frequency ~ 98 kHz) in motion. In dark environments, pigtail rats emit higher ultrasonic speeds in complex spatial environments and when avoiding obstacles. These results all show that the ultrasound emitted by the pigtail mouse plays a directional role in the movement behavior, that is, echo localization.
00:17
Pigtail Mouse in the Experiment Video Source: Interviewee (00:17)
Subsequently, the researchers used a classic experimental device and a rigorous experimental design to verify whether the pigtail rat had echo localization ability. Through behavioral task experiments, it was found that pigtail rats will spend more time and emit higher ultrasonic speeds to explore targets, they accurately detect the escape platform in complete darkness conditions, and successfully obtain food rewards; when its ears are blocked, pigtail rats cannot receive echoes and can no longer detect targets and complete tasks; after removing earplugs, pigtail rats recover the ability to explore and locate targets. Under the conditions of eliminating vision, touch, and controlled smell, behavioral experiments have confirmed that pigtail rats achieve localization goals by emitting ultrasound and using auditory reception echoes.
In addition, the researchers used technical means to present the skeletal anatomy of the pigtail rat, and found that its stem and hyoid bone were in contact with the spatial position of the drum bone and fused, which is consistent with the structure of the bat that is located by echo through laryngeal sound. This suggests that in terms of vocal and auditory structure, pigtail rats have the same anatomical structural basis as echolocation bats that emit laryngeal sounds.
Liu Qi and other researchers also sequenced and assembled a high-quality whole genome of the Chinese pigtail rat, and through evolutionary genomics analysis, it was found that the echolocation of the pigtail rat was of independent origin. Genome-wide, pigtail rats have significantly enriched their auditory genes with known echolocation species (bats and toothed whales).
By integrating multiple independent evidence from behavioral, anatomical, genomics, and gene function experiments, the echolocation ability of species of the rodent pigtail rat genus was confirmed.
It is expected to be applied to artificial intelligence, blind assisted navigation and other fields
The echo localization ability of pigtail rats seems to be incompatible with ordinary people. But Liu Qi said that this research may be applied to artificial intelligence in the future, such as improving autopilot driving and assisted navigation for the blind.
Liu Qi said that from the science itself, echolocation, as a special behavior of animals, is very rare in the animal kingdom. The echolocation species that humans know now may be limited to a few categories, such as bats and toothed whales, which are more familiar and unfamiliar to everyone, like some birds, shrews and horse island hedgehogs.
"In addition to the animals listed above, we confirmed that there is also a rat that also has echolocation skills, using hearing and ultrasound to find food or locate targets, which is very magical in itself!" Liu Qi said that in addition to the five taxa of independent origin such as bats, toothed whales and giant whales with echolocation capabilities, the research team found a sixth taxon with this ability.
In addition, because the pigtail rat belongs to the rodent class, the kinship, body size and model animal mice are closer, feeding and breeding is easy to operate and other factors, it is expected to become a new type of experimental animal for studying vocalization, hearing, echolocation neural circuits, etc.
Liu Qi said that based on the long-term research on echo-localized species such as bats, humans have developed many bionic products. For example, bats will emit ultrasonic waves to detect targets during fast flight, track moving prey, or avoid obstacles in time. The guide stick, invented accordingly, facilitates the movement of blind people.
He frankly said that there is still a lot of room for human research and application of echolocation, and the study of animals such as bats and pigtail rats and their echolocation can have more impact on human life in the future.
After discovering that pigtail rats have echo localization capabilities, Liu Qi and his research team have been wondering whether there are other mammals in nature that have this ability but have not been discovered. They hope that through the team's efforts, more such magical animals will be discovered.
"This requires the unremitting efforts of many researchers, and it may even be a very long exploration process." Liu Qi said that the discovery of pigtail rats and their echolocation is just the beginning, and they hope to stick to this research, hoping that in the future it can be used in artificial intelligence, such as improving autopilot driving in cars and assisted navigation for blind people.
Editor-in-charge: Yubing Tang
Proofreader: Ding Xiao