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.
  A:The first modern humans (Homo sapiens sapiens) appeared on earth around more than one hundred thousand years ago. They began to replace Neanderthal man (Homo sapiens neanderthalis or, more recently, Homo neanderthalis) in Europe around 50,000 years ago.ho they were and what they did represents a large field of study, pursued by Archaeologists, Anthropologists and Evolutionary Biologists. 1  According to Quran, Adam & Hawa were the first humans born on earth. 2  According to the Bible (Genesis Chapter 4), the first born person on earth was Cain, the child of Adam and Eve.