Out of Africa Theory Changed
An analysis of a 1.5 million-year-old vertebra from a human relative living in what is now Israel suggests that ancient humans dispersed out of Africa is multiple waves.
Transcript
00:00there is a continuous debate about the nature of out-of-Africa migration.
00:04Was this a one-time event, or did it take place on multiple occasions?
00:17The site of Ubediyah is found close to the southern edge of the Sea of Galilee,
00:22near Kibbutz Beit Zehra, and is one of the earliest prehistoric sites to be found
00:26outside of Africa, and dates to around 1.5 million years ago. The only other site that
00:32predates Ubediyah is Dmanisi in the Republic of Georgia, which dates to around 1.8 million years.
00:41Ubediyah was discovered and excavated in the early 60s by many of the famous
00:46Israeli prehistorians who uncovered rich stone tools assemblages that were used by early humans,
00:53together with numerous animal bones, some of which went extinct long time ago,
00:57like saber-toothed cats and mammoths, while others are not usually associated with Israel,
01:03such as hippos, rhinos, and big crocodiles. In 2018, Miriam Bellemaker won a National
01:10Science Foundation grant to study the ancient climate and to accurately date the site.
01:16While studying animal bones from the site, she came across a vertebra with a human-like feature
01:21that was actually excavated in 1966. Together with Professor Elabin, we studied the vertebra
01:28and came up with some new and important conclusions. First, it is a fossilized early
01:35human bone that belonged to a child. We know so because of the shape of the vertebra
01:40and the fact that it is incomplete, meaning that it did not finish its growing process.
01:46We estimate that, had it reached adulthood, this individual would be around 1.8 meters tall
01:53and weigh about 19 kilograms. These numbers are similar to some of the large-bodied hominins
01:59that are found in Africa in the similar time period, but are very different from the
02:06small-bodied hominins that we found in Georgia. Second, here we witnessed two distinct human
02:13species at the same time period, which is known as the lower Pleistocene, outside of Africa.
02:20We know that the earliest stages of human evolution took place in Africa,
02:26based on the fossil record and by comparing DNA data from apes and humans. However, over the years,
02:33there is a continuous debate about the nature of out-of-Africa migration. Was this a one-time event
02:40or did it take place on multiple occasions? And who were the people who migrated out of Africa?
02:47Our current study indicates that early hominins migrated at least twice and in two distinct ways.
02:54This is because the people of Dmanisi are different in size and shape from those in Ubadia.
03:00Moreover, Dr. Omri Barzilai studied the stone artifacts from both sides,
03:05concluded that the stone manufacturing techniques, as well as the stone tools themselves,
03:12are different. Professor Miriam Bellmaker concluded that the climate, as well as
03:16the animals, are also different in both sides. Thus, with each migration waves came new and
03:24different types of hominins, with their own stone-making traditions, which may indicate
03:30maybe about their cognitive abilities and the different preferences of their
03:36ecological niche inhabitants. Thank you for listening and have a great day.