Domestication of the dog began around 15,000 years ago and during this process, humans selected for particularly desirable traits such as coat colour and leg length.
This selection process has resulted in over 400 different breeds of dog, 209 are recognised by the UK Kennel Club.
Dogs have an incredibly well-developed sense of smell, far superior to humans.
At certain frequencies, dogs can detect sounds up to four times quieter than humans can hear. Dogs can also hear in ultrasound, which is sound with a frequency greater than the upper limit of human hearing.
Dogs can see better than humans in dark and dim light.
Communication is very important in helping dogs form and maintain social groups.
To transmit scent information, dogs use urine, faeces and secretions from special scent glands.
Many dogs can use their body, face, tail, ears and limbs to communicate with other dogs.
The fastest recorded speed for a greyhound is 42 miles per hour, similar to that of a mounted racehorse, which can reach speeds of around 43 miles per hour.
Dogs actively seek information about their surroundings and will spend much time investigating and exploring.