The value of animal skeletal specimens goes far beyond their ornamental function in science popularization exhibitions. They play an irreplaceable role in scientific research, education, archaeology, forensic medicine and other fields. In evolutionary biology research, skeletal specimens are the **key evidence** for exploring species evolution. There are differences in the skeletal structures of different species, and these differences record the evolutionary trajectories of species adapting to the environment. For example, by comparing the skeletal specimens of modern birds with those of ancient dinosaurs, scientists have found many similarities between the wing bones of birds and the forelimb bones of dinosaurs, which provides strong support for the theory that **birds originated from dinosaurs**. In addition, by analyzing the fossil specimens of animal bones from different geological ages, scientists can also reconstruct the ancient ecological environment and understand the rise and fall of species. In the field of education, skeletal specimens serve as intuitive **anatomical teaching aids**. For students majoring in biology and medicine, observing animal skeletal specimens enables them to quickly grasp knowledge such as animal skeletal structure, joint connection, and muscle attachment points, which is more intuitive and easier to understand than simply reading textbooks. For instance, in veterinary education, skeletal specimens of common animals like dogs and cats can help students familiarize themselves with animal skeletal anatomical structures, laying a solid foundation for subsequent clinical diagnosis and surgery. Skeletal specimens also play an important role in archaeology and forensic medicine. By studying the skeletal specimens of ancient animals, archaeologists can understand the production and living methods of human beings at that time. For example, analyzing the bones of domestic animals can help judge the level of agricultural development in that period. Nowadays, with the development of technology, the production and application of animal skeletal specimens are constantly innovating. For example, 3D scanning technology can accurately replicate precious skeletal specimens, which not only facilitates resource sharing among researchers but also avoids damage to the original specimens. In virtual museums, digital skeletal specimens allow audiences to observe skeletal structures 360 degrees through interactive operations, enhancing the science popularization experience. A single animal skeletal specimen carries the history of life, embodies the craftsmanship of its maker, and unlocks the mysteries of nature. 

The discoloration of wax leaf specimens is mainly caused by light, humidity, oxidation of plant components, and improper handling. The core avoidance strategy is to control environmental factors, optimize the production process, and do a good job in post production protection. The specific methods are as follows. 1、 Collection and preprocessing stageChoose an appropriate collection timeAvoid collecting under high light at noon (when plant cells have vigorous metabolism and are prone to rapid dehydration leading to pigment degradation), and prioritize collecting in the early morning or evening; After collection, immediately place it in a sealed fresh-keeping bag (temporary storage) to avoid prolonged exposure of plants to air and reduce the oxidation of pigments such as chlorophyll and anthocyanins.Targeted treatment of special plantsPlants containing polyphenols and tannins (such as tea leaves and acorn leaves): After collection, quickly boil them in boiling water for 10-20 seconds (to kill them), destroy the oxidase activity, and then suppress them;Succulent/succulent plants (such as Sedum and Portulaca): First, remove excess fleshy tissue, use absorbent paper to absorb surface moisture, and then press to avoid water retention and browning;Flower specimens: Gently separate petals and avoid overlapping when spreading to reduce discoloration caused by high local humidity. 2、 Compression drying stageIncrease the frequency of replacing absorbent paperChange the absorbent paper 2-3 times a day in a humid environment (at least once in a dry environment) to keep it dry and avoid mold growth or pigment hydrolysis of the specimen due to moisture retention; When changing paper, handle with care and do not rub the specimen to prevent cell damage and accelerated oxidation.Control and suppress the environmentThe suppression area should be ventilated, dry, and away from light (can be placed in a cool indoor corner), and avoid direct sunlight (ultraviolet rays can damage chlorophyll and cause yellowing of leaves); If the environment is humid, a desiccant (silica gel) can be placed next to the specimen holder to accelerate water evaporation.Moderate pressureThe pressure of the specimen clamp is moderate (it is advisable to fix the specimen flat without squeezing the organs). If it is too tight, it will cause cell rupture and pigment exudation; If it is too loose, the specimen will not have sufficient contact with the absorbent paper, and uneven drying will cause local discoloration. 3、 Disinfection and Binding StageChoose a gentle disinfection methodPrioritize low-temperature disinfection (freezing at -20 ℃ for 48 hours) to avoid damage to pigments caused by chemical fumigation (such as bromomethane); Ordinary teaching specimens can be exposed to short-term sunlight (1-2 hours), but it is necessary to avoid fading caused by prolonged exposure.Avoid using easily dyed materials for binding materialsUse neutral glue (such as white latex) or pure cotton needle and thread binding, avoid using acidic glue or colored string (acidic substances can corrode specimens, colored materials may fade and contaminate specimens); Select acid free cardboard for the table paper (to prevent acidic substances from seeping out after the paper ages, causing the specimen to turn yellow).