Life coach: why does my stomach grumble?

PhotonQ-Noel de Chien
High Frequency Hearing Aids
Image by PhOtOnQuAnTiQuE
How does a dog perceive the world. That’ s one of the questions I was wondering while taking his picture. So here are few interesting facts I came across =)

Vision

Like most mammals, dogs are dichromats and have color vision equivalent to red-green color blindness in humans (deuteranopia).

The dog’s visual system has evolved to aid proficient hunting. While a dog’s visual acuity is poor, their visual discrimination for moving objects is very high; dogs have been shown to be able to discriminate between humans (e;g. identifying their owner) from distances up to a mile.
As crepuscular hunters, dogs often rely on their vision in low light situations:
they have very large pupils, a high density of rods in the fovea, an increased flicker rate, and a tapetum lucidum. The tapetum is a reflective surface behind the retina that reflects light back to give the photoreceptors a second chance to catch the photons. A Dog’s Life: Dog Vision(short video)

Smell

While the human brain is dominated by a large visual cortex, the dog brain is dominated by an olfactory cortex. The olfactory bulb in dogs is roughly forty times bigger than the olfactory bulb in humans, relative to total brain size, with 125 to 220 million smell-sensitive receptors.
The bloodhound exceeds this standard with nearly 300 million receptors. Dogs can discriminate odors at concentrations nearly 100 million times lower than humans can.
The wet nose is essential for determining the direction of the air current containing the smell. Cold receptors in the skin are sensitive to the cooling of the skin by evaporation of the moisture by air currents.

Hearing

The frequency range of dog hearing is approximately 40 Hz to 60,000 Hz, which means that dogs can detect sounds far beyond the upper limit of the human auditory spectrum.
Additionally, dogs have ear mobility which allows them to rapidly pinpoint the exact location of a sound. Eighteen or more muscles can tilt, rotate, raise, or lower a dog’s ear. A dog can identify a sound’s location much faster than a human can, as well as hear sounds at four times the distance.

There are estimated to be 400 million dogs in the world.

And something interesting to think about co-evolution :

Domesticated dogs got advantages that wolves never had—more safety, more reliable food, lesser caloric needs, and more chance to breed.

Humans have an upright gait that give them larger range over which to see both potential predators and prey, as well as color vision that at least by day give humans better warning of predators that could be dangerous to both humans and dogs.

With their tool use, humans could get dogs to take more specialized roles in a hunt. Humans and dogs together could hunt prey that neither humans nor wolves could detect and subdue without aid from the other.
Dogs and humans together out-competed other large predators and crowded wild wolves, bears, and big cats out in their range and thus share the top of the food chain. wikipedia

Life coach: why does my stomach grumble?
Your first step is to get a good hearing test – this is possible in many commercial high street hearing aid outlets, but can also be arranged via the NHS by your GP. Hearing loss may be fairly subtle or affect only certain frequencies but if, as is …
Read more on Telegraph.co.uk

Moth's Superhearing Evolved to Escape Bats
The greater wax moth can hear at a higher frequency than any other animal on Earth, according to a new study. These insects, whose ears are each only … The results showed that the moths ended up topping out at about 300 kHz—a pitch so high that even …
Read more on National Geographic




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