Hybrid-origin

The Hybrid-origin hypothesis of human origins argues that all or at least some of the genetic variation between the contemporary human races is attributable to genetic inheritance from at least two widely divergent Hominina subspecies, that were geographically dispersed throughout Africa, Southeast Asia and the Indian subcontinent, prior to the evolution of modern Homo sapiens sapiens (according to hybrid-origin theory, approximately 35,000 years ago).

Hominid populations, put forward by the hybrid-origin theory as sources for genetic admixture, include Homo neanderthalensis and Peking Man (a subspecies of Homo erectus), and Cro-Magnon man (who physically and culturally differs significantly from Homo erectus).This theory was first introduced in 1971 by the British psychologist Stan Gooch.

Theory outline

Here is a brief summary of Gooch's theory (from "Guardians of the Ancient Wisdom" 1979):

# From other human species, Cro-Magnon man evolves in Northern India during millions of years of isolation, develops and practices sun worship and hunting magic; the culture is patriarchal.
# Elsewhere during the same period, different forms of Neanderthal evolve in Europe and the Middle East, while moon worship and earth magic is developed and practiced; the culture is matriarchal.
# Around 35,000 years b.p. Cro-Magnon abandons India and heads west through the Middle East into Europe, overrunning Neanderthal. By 25,000 years ago, the predominant type in Europe is Cro-Magnon.
# In the Middle East a hybrid population, a cross between the Cro-Magnon and Neanderthal types, emerges. Pure Neanderthal has largely ceased to exist either here or in Europe.
# By 15,000 years ago, pure Cro-Magnon man has also ceased to exist, driven out of north and west Europe, into southern Europe, by renewed glaciation, absorbed by the hybrid type (that is, ourselves).

Meanwhile mixed types have also migrated back into Africa (during glaciation in Europe the Sahara had become well-watered, grassy plains) and back into India and then on to China. In these places the mixed type further mingled with the local Neanderthal types.

According to this theory the resulting hybrid 'Homo sapiens sapiens', was superior to both its ancestors due to what is commonly termed hybrid vigour.

ee also

*Recent single-origin hypothesis
*Multiregional hypothesis
*Punctuated equilibrium
*Interbreeding of Cro-Magnon and Neanderthals

Further reading

;"Pan"-"Homo" hybrid
* [http://www.nytimes.com/2006/05/18/science/18evolve.html?pagewanted=2&_r=1 NYTimes.com] - "Two Splits Between Human and Chimp Lines Suggested", "New York Times" (May 18, 2006): "The analysis, by David Reich, Nick Patterson and colleagues at the Broad Institute in Cambridge, Mass., sets up a serious conflict between the date of the split as indicated by fossil skulls, about 7 million years ago, and the much younger date implied by genetic analysis, as late as 5.4 million years ago. The conflict can be resolved, Dr. Reich's team suggests in an article published in today's "Nature", if there were in fact two splits between the human and chimp lineages, with the first being followed by interbreeding between the two populations and then a second split."