Coastal Migration Theory and I:
A new paper on another archaic hominin species and their admixture in Homo Sapiens is out. According to the study, hominin species labeled as 'Denisovans', remains of whom found in Siberia, were related to Neanderthals. Let me call our old friend Neanderthals as N. Euskaria and these Denisovans as N. Siberia.
A previous study found N. Euskaria admixture in all of Eurasian Sapiens but not in African Sapiens. This was considered as a proof of early Sapiens meeting with N. Euskaria in middle east and their subsequent dispersal to all over the world.
Now the new study has found N. Siberia admixture in Melanesians but which supposedly missing in other Euraisans and Africans. These two studies have a bearing on my model of the northern route migration of Homo Sapiens.
Until now I have based my opposition to the coastal migration theory on two counts.
- Lack of common sense in the model considering India is a tropical country like Sapiens' original home in Africa and there was no pressing need for further migrations to SE Asia and Oceania. I have proposed that the movement thro' temperate landscape would develop the wanderlust that our ancestors have been famous for in occupying the whole of Eurasia in a quick time. They migrated in search of a tropical climate until they reached SE Asia.
- The second factor is genetic. The lack of uniparental lineage Y-Haplogroup D, associated with the coastal migration, in India and the uniform distribution of Y-Haplogroup C (which is now strangely considered as "intrusive" Ancient North Indian or not part of the original gene pool -which has been called Ancient South Indian- in a recent study) cannot be overlooked. Along with the fact that India's so-called oldest mtDNA lineage M2 is mostly observed in East India. This of course gives evidence for migration from SE Asia to India (and then further into Middle East and Europe).
Probably, I need to give add one more factor or probably replace the common sense approach to more circumspect scenario.
Now we know that N. Euskaria and N. Siberia interbred with us. We also know that we don't have N. Euskaria an N. Siberia Y-Haplogroup or mtDNA lineages. There could be two scenarios.
1. Male Sapiens and Female Neanderthal species mated and produced only fertile males and sterile females. Therefore, only Sapiens' uniparental lineage survived.
2. Female Sapiens and Male Neanderthal species mated and produced only fertile females and sterile males. Therefore, only Sapiens' uniparental lineage survived.
We really don't know whether both scenarios were in vogue or only one of them had occurred. But since both N. Euskaria and N. Siberia were Neanderthal species we could see that above two scenarios have been found consistently true.
I would propose the reason for Sapiens' rapid migration along northern route from middle east to Siberia and from there to SE Asia along western east Asia is related to the second scenario.
It has been observed that Neanderthal communities always had lower percentage of females or lacked enough females so all males could have sex and/or procreate, a situation similar to Haryanvis. It was a common practice for a Neanderthal group to abduct females. In contrast the oldest Sapiens had excess females. So what would happen when a Hominin with enough females meet another Hominin that has scarcity.
Evidently there was a very strong evolutionary pressure on Neanderthals to abduct Sapien females than vice versa. This had resulted in Sapiens' rapid migration from middle east to central Asia to escape from N.Euskaria. But unfortunately for them there they would meet N.Siberia who had similar evolutionary pressure since they were also a branch of Neanderthals.
So, we do see Siberia admixture among one of the Y-Haplogroup C population in Oceania, Melanesians. Since the admixture is clearly because of a species related to Neanderthals and not any Erectus branch in SE Asia, we can say that northern route was taken by the early Sapiens.
1. Estimators of the Human Effective Sex Ratio Detect Sex Biases on Different Timescales
- Emery et al. (2010)
2.Genetic history of an archaic hominin group from Denisova Cave in Siberia
- Reich et al (2010)
3. A Draft Sequence of the Neandertal Genome
- Richard E Green et al. (2010)
4. Reconstructing Indian population history
- Reich et al (2009)
5. The documentary I saw either on Discovery or National Geographic channel