Exploring the Origins of Today's Humans

Summary:
Where did we humans come from? When did we become the dominant species on the planet? Available evidence indicates that all humans living today are derived from a relatively small population that arose in Africa beginning >200,000 years ago, spreading throughout Africa and eventually the rest of the planet. In the course of this diaspora, we mated with other human-like species and assimilated some of their DNA, but eventually replaced all of these other close evolutionary cousins, without exception – leaving only one human species today. A flood of new information from Ancient DNA, Fossils, Archeology and Population Studies calls us to revisit the matter, summarizing knowledge and updating conclusions since the last CARTA symposium on the subject six years ago.

Event Sessions:

Media for each talk can be played by clicking on icons in the table below, or by clicking on the individual talk titles below and then the attachment file at the bottom of the page.

Speakers	Media	Session
Pascal Gagneux Mark Collard		Welcome & Opening Remarks
Jean-Jacques Hublin		Homo sapiens Origins: when “Moderns” were Archaic. The last half million years witnessed a remarkable diversification of hominin lineages. Among them early Homo sapiens, Neandertals and Denisovans displayed the widest geographical distribution. Although genetics sheds some light on their mutual relationships, the early phases of their evolution are poorly documented in the fossil record. The site of Jebel Irhoud in Morocco yielded the oldest evidence regarding the ancestry of our own species in Africa, in direct association with a well... read more
Katerina Harvati-Papatheodorou		Homo sapiens dispersals out of Africa The timing and number of early dispersals of Homo sapiens out of Africa is a matter of great interest and debate. Broad consensus exists that the major dispersal of early modern humans started 70-50 thousand years ago (ka), reaching the Near East by 60 ka and Europe by 45 ka, and eventually replacing archaic humans around the world. However, a well documented population of early Homo sapiens is known to have lived in the Near East already by 130-100 ka, raising the possibility of earlier... read more
Tim Weaver		The evolution of the human skull The skulls of today's humans differ from those of Neandertals and other members of the genus Homo in a number of ways. By identifying these differences in fossils—as well as with evidence from the genomes of present-day and ancient individuals––it has been possible to trace the emergence of our evolutionary lineage to Africa. So, we now know the continent our lineage came from. But when and how rapidly did our distinctive skull anatomy appear? And why don't our skulls look like those of other... read more
John Hawks		How Homo naledi matters to our origins Today’s humans all over the world derive most of their ancestry from African populations that lived before 100,000 years ago. The period from 350,000 to 100,000 years ago in Africa was the time when the initial population diversification of modern human groups happened. Until recently, most anthropologists thought that Homo sapiens was alone on the African continent during this critical time period. In 2013, our team working in the Rising Star cave system in South Africa uncovered the new... read more
Sriram Sankararaman		Recovering signals of ghost archaic introgression in African populations While introgression from Neanderthals and Denisovans has been documented in modern humans outside Africa, the contribution of archaic hominins to the genetic variation of present-day Africans remains poorly understood. We provide complementary lines of evidence for archaic introgression into four West African populations. Our analyses of site frequency spectra indicate that these populations derive 2 to 19% of their genetic ancestry from an archaic population that diverged before the split of... read more
Paola Villa		The Archaeology of Ancient Tools The earliest known stone tools have been found at the site of Lomekwi in Kenya and are dated to 3.3 million years. Metal (copper) tools appear in several places by about 4000 B.C. onward and slowly replaced stone weapons and domestic tools. In brief, humans used stone tools for 3 million years. Bone tools and tools made of wood were also used throughout this long period but lithic tools were always the most common. The long history of stone tools is punctuated by important innovations such as... read more
Teresa Steele		Continuity or Punctuation in the African Archaeological Record After 500,000 Years Ago When investigating how, when and where our ancestors in Africa gained the ability to expand globally and to replace, for the most part, existing occupants, we often examine the archaeological record for evidence of increasing human behavioral complexity. “Sophisticated” stone tool technology, the manufacturing of bone tools, the use and engraving of pigments, the employment of mollusk and ostrich eggshell beads, and the control of fire for cooking, heating stone materials, and processing... read more
Joshua Akey		Tales of human history told by Neandertal and Denisovan DNA that persist in modern humans It has become well known over the past few years that as anatomically modern humans dispersed out of Africa, they encountered and mated with other hominins such as Neandertals and Denisovans. The ability to identify and excavate extinct hominin DNA from the genomes of contemporary individuals reveals considerable information about human history and how encounters with Neandertals and Denisovans shaped the trajectory of human evolution. I will show how catalogs of surviving hominin lineages... read more
Iain Mathieson		Using ancient DNA to track the evolution of today’s humans As humans migrated throughout the world, they experienced new and challenging environments. They also created new environments for themselves, for example through the development of agriculture. The traces of genetic adaptation to these environments can be seen in our genomes and phenotypes today. By analyzing ancient DNA–genetic data directly from ancient humans–we are able to watch evolution in action, and observe adaptation as it happens. Here, I summarize what these data have told us about... read more
All Speakers		Wrap-up, Question and Answer Session, Closing Remarks