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.
According to this model, modern humans evolved in East Africa, and started to disperse through the world roughly 50,000 to 100,000 years ago. The single-origin hypothesis is cited as having the scientific consensus as of the mid-2000s.