Chihuahua Dog Breed. First discovered in Mexico, the Chihuahua is best known for being the smallest dog breed in the world. Extremely loyal to its owner, the breed has recently become a popular culture icon in the United States, most notably Paris Hilton's Chihuahua, Tinkerbell. Physical Characteristics.
Earth formed around 4.54 billion years ago by accretion from the solar nebula. Volcanic outgassing probably created the primordial atmosphere and then the ocean; but the atmosphere contained almost no oxygen and so would have been toxic to most modern life including humans.
According to human evolution, humans as they are now first appeared on the earth around 250,000 years ago.n the bible, in the book of genesis you will find that the first person on earth is Adam   Another answer: All of the evidence that has been accumulated suggests that th â¦ ere was no first human. Humans gradually became differentiated from their ancestors.