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
00:00 there is a continuous debate about the nature of out-of-Africa migration.
00:05 Was this a one-time event or did it take place on multiple occasions?
00:09 The site of Ubedia is found close to the southern edge of the Sea of Galilee,
00:22 near Kibbutz Beidzera,
00:23 and is one of the earliest prehistoric sites to be found outside of Africa,
00:27 and dates to around 1.5 million years ago.
00:31 The only other site that predates Ubedia is Dmanisi in the Republic of Georgia,
00:36 which dates to around 1.8 million years ago.
00:40 Ubedia was discovered and excavated in the early 60s
00:45 by many of the famous Israeli prehistorians
00:48 who uncovered rich stone tools assemblages that were used by early humans,
00:53 together with numerous animal bones,
00:55 some of which went extinct long time ago, like saber-toothed cats and mammoths,
00:59 while others are not usually associated with Israel,
01:03 such as hippos, rhinos, and big crocodiles.
01:06 In 2018, Miriam Bellemaker won a National Science Foundation grant
01:11 to study the ancient climate and to accurately date the site.
01:16 While studying animal bones from the site,
01:18 she came across a vertebra with human-like feature
01:21 that was actually excavated in 1966.
01:25 Together with Professor Elabin, we studied the vertebra
01:28 and came up with some new and important conclusions.
01:32 First, it is a fossilized early human bone that belonged to a child.
01:37 We know so because of the shape of the vertebra and the fact that it is incomplete,
01:42 meaning that it did not finish its growing process.
01:47 We estimate that had it reached adulthood,
01:48 this individual would be around 1.8 meters tall and weigh about 19 kilograms.
01:56 These numbers are similar to some of the large-bodied hominins
01:59 that are found in Africa in the similar time period,
02:05 but are very different from the small-bodied hominins that we found in Georgia.
02:10 Second, he will witness two distinct human species at the same time period,
02:16 which is known as the lower Pleistocene outside of Africa.
02:20 We know that the earliest stages of human evolution took place in Africa,
02:26 based on the fossil record and by comparing DNA data from apes and humans.
02:31 However, over the years, there is a continuous debate
02:35 about the nature of out-of-Africa migration.
02:38 Was this a one-time event or did it take place on multiple occasions?
02:43 And who were the people who migrated out of Africa?
02:47 Our current study indicates that early hominins migrated at least twice,
02:52 and in two distinct ways.
02:54 This is because the people of Dmanisi are different in size and shape from those in Obadiah.
03:00 Moreover, Dr. Omri Barzilai, who studied the stone artifacts from both sides,
03:05 conclude that the stone manufacturing techniques,
03:09 as well as the stone tools themselves, are different.
03:13 Professor Biryam Belmecker concludes that the climate,
03:15 as well as the animals, are also different in both sides.
03:20 Thus, with each migration waves came new and different type of hominins,
03:27 with their own stone making traditions,
03:29 which may indicate maybe about their cognitive abilities
03:34 and the different preferences of their ecological niche inhabitants.
03:39 Thank you for listening and have a great day.
03:42 [music]
03:45 [silence]