Common Design Features: All spring aligners are available for both arches. Standard design is 3-3, although 4-4 is very common & often used when canine correction is desired. Wraparound designs are also available with Mushroom & Super Spring designs.
exists and is an alternate of . The most generally accepted scientific theory states that the first humans (defined as members of the genus Homo) originated in Africa. The oldest known fossil of a human ancestor (a female Ardipithecus ramidus specimen nicknamed Ardi, 3.2 million years old) at a site called Aramis in the Middle Awash region of the Afar Desert in Ethiopia.
Researchers generally have believed the first human beings in the Americas came over a land bridge there from Asia, but disagree how they spread south.