The modern working definition of a gene is a portion (or sequence) of DNA that codes for a known cellular function or process (e.g. the function make melanin molecules). A single 'gene' is most similar to a single 'word' in the English language.The nucleotides (molecules) that make up genes can be seen as 'letters' in the English language. Nucleotides are named according to which of the four nitrogenous bases they contain. The four bases are cytosine, guanine, adenine, and thymine.he modern working definition of a gene is a portion (or sequence) of DNA that codes for a known cellular function or process (e.g. the function make melanin molecules). A single 'gene' is most similar to a single 'word' in the English language.
Where did humans first appear on Earth, and what were their society, technology, and culture? Humans first appeared on Earth during the Paleolithic Era, in the steppes and savannah of Africa, before migrating to Eurasia, the Americas, and Australia. These humans were hunter-foragers, changing their tools and culture to adapt to their surroundings. Describe earliest humans' technology & tools.
A map of early human migrations. Homo sapiens seem to have appeared in East Africa around 200,000 years ago. The oldest individuals found left their marks in the Omo remains (195,000 years ago) and the Homo sapiens idaltu (160,000 years ago), that was found at the Middle Awash site in Ethiopia.he expansion of modern human population is thought to have begun 45,000 years ago, and may have taken 15,000-20,000 years for Europe to be colonized. During this time the Neanderthals were slowly being displaced.