Africa is the world's second largest and second most populous
continent, after Asia. At about 30.2 million km2 (11.7 million
sq mi) including adjacent islands, it covers 6% of the Earth's
total surface area and 20.4% of the total land area. With 1.05
billion people (as of 2011, see table) in 55 territories, it
accounts for about 15.12% of the world's human population. The
continent is surrounded by the Mediterranean Sea to the north,
both the Suez Canal and the Red Sea along the Sinai Peninsula to
the northeast, the Indian Ocean to the southeast, and the
Atlantic Ocean to the west. The continent has 54 sovereign
states, including Madagascar and various island groups. Africa,
particularly central Eastern Africa, is widely regarded within
the scientific community to be the origin of humans and the
Hominidae clade (great apes), as evidenced by the discovery of
the earliest hominids and their ancestors, as well as later ones
that have been dated to around seven million years ago –
including Sahelanthropus tchaden