Red-necked keelback snakes possess a potent toxin derived from the toads they consume, which can cause severe harm to predators like mongooses. The snakes store these toxins in specialized nuchal glands.
The bodies of the crabs displayed male reproductive structures, while other parts showcased female features, including gonopores, said K.S. Anoop Das.
Human breasts sit at an elevated temperature, protecting a newborn from hypothermia. What's more, the size and shape of the breast allows for broad contact surface - enhancing the heat transfer from mother to child. This could improve a newborn's chances of survival and provide an evolutionarily grounded explanation for the development of external breasts in humans.
Such sex 'distorters' have been discovered - and studied in great depth - in laboratory animals such as mice and flies, in which their effects can be detected through selective breeding. 'If you look, more often than not, you find them,' says Nitin Phadnis, an evolutionary geneticist at the University of Utah in Salt Lake City, who co-led the study.
In a naturalistic rendition of David vs. Goliath, a 28-pound Reeves's muntjac named Tata, a small deer species native to Asia, took on Maruśka, a 1.7-ton female rhinoceros, in a fierce head-to-head at the Wroclaw Zoo in Poland. A video that's gone viral on social media shows the miniature deer fiercely standing its ground and charging at the far more massive rhino, clashing into its horn-tipped snout with tiny antlers.
The mirror spider can rapidly shift a patchwork of minuscule reflective plates underneath its abdomen's outer surface, altering the pattern of mirrorlike flashes. This uncommon display comes from common building blocks: Similar tilelike arrangements of plates and soft joints appear throughout the tree of life, from turtle shells to tropical fruit peels. Researchers have now compiled 100 examples of this pattern across animals, plants, microbes and viruses, which they describe in PNAS Nexus.
The study's authors researched 96 peer-reviewed studies documenting SSB to compile one of the most comprehensive datasets for primates to date. The study found that SSB are a "persistent and integral component of primate social [practices]." In fact, the prevalence of SSB across a variety of closely related primate species - and over several lines of descendants - "indicates a deep evolutionary root or multiple independent evolutionary origins," the study's authors wrote.
What's scarier than a spider? A really big spider, of course. A newfound defensive tactic takes advantage of this idea: researchers documented spiders building giant spiderlike silhouettes on their webs to ward off predators. These decoys are an example of web decorations that some spiders are known to produce, often to prevent getting eaten, avoid bird strikes or attract prey.