The Path From the Old World to the New

The map above shows the theory about how human beings moved from Africa to the rest of the world. The letters refers to mtDNA - the Haplogroups that pass from mother to child.

The five major lineages that make up Native Americans are A, B, C, D, and X. Most scientists believe that America was initially settled from Asia and this is supported by most of the genetic evidence. Most Native Americans are genetically linked to Asia. This fits the long standing theory that the people who populated the two American continents walked across the land bridge that connected Asia with North America during the ice age and later theories that envision boats following the coasts.

The map below shows the distribution of MtDNA lines in America. Lines A through D are the dominant ones and clearly came from Asia. They are distributed throughout North and South America. But X is concentrated in northeast North America. And what is the "other MtDNA" shown for North America?

 americanscientist.org/my_amsci/restricted.aspx?act=pdf&id=2885494546964

The map below illustrates the current location of Male "Y" haplogroups passed from father to son. This is the DNA from the indigenous people - Native Americans and Australian Aboriginals. Note that the America's are populated by descendants of three major groups.

Click to view a larger map.  https://upload.wikimedia.org/wikipedia/commons/c/ca/World_Map_of_Y-DNA_Haplogroups.png

The map below shows the distribution of the male haplogroup "Q", which is inherited from father to son. Most male Native Americans share this haplogroup and it is clear from the map that it spread from north east Asia into America. It appears to be the signature for the first migrants still reflected in current Native Americans. Both continents were settled.

The map below shows the distribution of the male haplogroup "C3".  People with this haplogroup clearly came from Asia and judging from the map, was a later migration into the new world. It did not go further south, probably blocked by earlier migrants to the new world.

Maps are from Wikapedia.

Patterns That Look Like Movements From West Asia or Europe to America

But not so fast. The maps below show patterns that appear more likely to have originated in west Asia and Europe. It is possible that migrants originated in Asia and went by land to America but died out in east Asia and northwest North America, leaving little trace.  This seems unlikely.

The maps above shows the distribution of the male Y Chromosome "R"  Y-DNA, passed from father to son. Most sources contend that this Haplogroup came about in Native Americans recently from post Columbian American colonists. 

Some R-1 no doubt did come from recent European migrants. But the concentration in northeast North America seems too high for all of it to be Post Columbian.  And there is little reason to think that the percentage of R-1 would be so much higher in northeast North America than in other parts of North and South America. 

Wikapedia addresses this issue

A second theory that was introduced during European colonization^[42] can be excluded for the following reasons:^[45]

1. SNP array-based analyses using a data set masked for inferred admixed genomic regions19 gave no matches with recent European admixture.^[45]
2. Allele frequency-based D-statistic tests20 show that all 48 tested modern-day populations with First American ancestry19 are equally related to MA-1 within the resolution of our data, which would not be expected if the signal was driven by recent European admixture.^[45][46]
3. MA-1 is closer to Native Americans than any of the 15 tested European populations.^[45][47]

Central and South America have had longer post Columbian histories of intermarriage than northeast North America but R1 barely shows up there. 

The map above shows the world distribution of haplogroup X, the fifth founding maternal lineage in America. Unlike haplogroups A through D, it is found primarily in West Asia, Europe, and North America. And unlike haplogroups A through D which are distributed throughout North and South Ameria, it is found primarily in northeast North America.  

It was initially thought that persons with this haplogroup were descended from post Columbian European immigrants but now it has been determined that the haplogroup is very old in North America and much different from the X found in Asia and Europe.

The two maps above depict minor DNA lineages in Native Americans that originated in West Asia and Europe and are now primarily in northeast North America.  It is possible that the came from Siberia and then died out in Asia and for some reason did not expand into South America.  But it seems most likely to me that they got to North America by crossing the Atlantic.  

The alternate assumes that they immigrated across Asia and western North America but left little genetic trace of their passage in Asia and northwest North America. And unlike the other Native American groups they are concentrated in northeast North America.

I am certainly not a DNA expert.  But I can read maps. 

Most of the DNA evidence supports immigration from Siberia into the Americas and most Native Americans are descended from these people.

But the male line R1-M173 and the female line X are in my opinion more likely the result of seaborne expansion from west Asia and/or Europe into the new world.

And the two expansions from Asia and Europe/the middle east into America likely occurred at roughly the same time, with the R-M173 and X probably coming into America shortly after the main Native American lineages arrived from northwest Asia. The two peoples would have expanded into their respective territories and then met in the middle, where they blocked further expansion and where over time there has been significant gene exchange. The immigration from Asia continued on to populate central and South America.

Many people believe that the R1-M173 in Native American populations is post Columbian. But it is hard to see that this would have been so strong in northeast North America but not elsewhere.   

Denisova DNA

The graphic above is interesting. It shows the world location of of people with Denisova alleles. Interbreeding with Denisova individuals took place much earlier than movement into the Americas.  

The people of Oceania have the most genetic evidence of interbreeding with Denisovians.  The people of Oceania have the most genetic material from Desinova.

But look at the concentration in the north part of South America. The map looks like a migration by sea from Oceania. The alternative explanation is that the migration came from Siberia over the land bridge but let little trace in North Asia and North America. Rather unlikely.

Anomolous DNA

Click on the link below for an interesting discussion of Anomalous DNA found in Native Americans.

"In the past, whenever a geneticist or anthropologist conducting a study of Native Americans has encountered an anomalous haplogroup, that is, a lineage that does not belong to one of the five generally accepted American Indian mitochondrial DNA haplogroups A, B, C, D and X, it has been rejected as an example of admixture and not included in the survey results. 

Lineage A, B, C, D and X are American Indian.

Therefore, all American Indians are lineage A, B, C, D and X.

The fallacy in such reasoning is apparent. It could be restated as: "All men are two-legged creatures; therefore since the skeleton we dug up has two legs, it is human." It might be a kangaroo."

http://dnaconsultants.com/_blog/DNA_Consultants_Blog/post/Anomalous_Mitochondrial_DNA_Lineages_in_the_Cherokee/