To understand the biology of the modern golkh, we need to understand where they came from. Let’s start out by examining an early ancestor: Primonasus sp., of the tribe Primonasini in the subfamily Procyoninae.
Primonasus was omnivorous, eating fruit, insects, fungi, and occasionally small birds and rodents. They lived in temperate forested habitats. They were semi-arboreal, scaling trees to avoid predators and forage for food. A partly opposable hallux and pollex assisted them in climbing.
Climatic shifts began to erode at the forest ecosystem. Drier interiors made forests give way to woodlands, to savannah, and eventually to arid grasslands. Organisms had to adapt to increased heat and limited food. Primonasus was in a good position to adapt for food scarcity: good at scavenging/foraging and able to use a variety of resources for food. This second capability further developed in the desert. They supplemented their diet with scavenging, and eventually evolved resistances to many common pathogens found in meat in the early stages of decay.
Using tools (a capability Primonasus already possessed) helped with foraging – tearing thick hide from carcasses, chopping through woody coverings around tubers, extracting grubs from borrows, mounds or trees. As tool use became critical to survival, a fully opposable pollux was selected for.
This brings us to bipedalism. Primonasus already could stand on its hind legs. Permanent bipedalism freed up the front limbs for better tool use. Fast moving wasn’t as important for them as it was for humans. They were primarily scavengers, not pursuit hunters, using tools for extractive foraging (and, occasionally, disuading their few natural predators). As such, the posture they used for walking wasn’t particularly efficient – there was never the selective pressure to force them to adapt to quick movement. Their gait was slow and shambling, and, though they could stand more or less upright, they typically walked with bent knees and a forward-angled back. To help balance, their foot shape somewhat changed, resulting in their halluces no longer being opposable. However, their toes remained far more dextrous than that of humans, allowing them to more easily navigate rough terrain.
Heat was also a factor that shaped the modern Golkh. Like humans, they lost most of their fur. (Yes, that’s the reason that I often draw them with wrinkles – their modern forms bear a slight resemblance to a sphynx cat, or a Mexican hairless dog). However, they didn’t keep a patch of hair over their head. In humans, this patch shielded the head from the sun. Given human bipedalism, this was especially important, as their heads were far more exposed than the rest of their body. However, the stance of these early Golkh exposed both the head and the back of the torso to the sun. Instead of hair, the Golkh instead relied on preexisting traits of their coloration. Like many carnivora, Primonasus exhibited countershading – a lighter underbelly and a darker top. In the desert, this feature adapted for sun protection. In addition to a large overall increase in melanin production, the back and top of the head of these early Golkh became much darker. (Like in humans, this trait would diversify as the Golkh moved into different climates, with different groups having different skin colors, but some trace of the darker back would always remain.)
Golkh also had to deal with heat dispersion. However, they didn’t need to be as efficient at this as humans. Sweating for evaporative cooling is useful in humans in part because it can be toggled on and off – greater exertion heats up the body and triggers sweating. But, again, the Golkh were scavengers, not pursuit hunters. They lived at a fairly constant rate of exertion. Sweating, as such, didn’t have as many advantages, and was a waste of valuable water in an arid environment. Instead, the ears of Golkh enlarged (an adaptation seen in many hot-habitat creatures – big ears means more surface area, which means better heat dispersal.)