The Mari seem to be linguistically, ethnically tied to the Saami (Laps) of Scandinavia. Language related to Finnish, Hungarian, Estonian etc.
Physical appearance of both Saami and Mari varies, with some having Asian type eyes, but some also having blond or red hair.
http://s1.zetaboards.com/anthroscape/topic/4825891/1/
That is a cool site, for the Uralic people of Russia.
My female friend was the one that created a written language for the Mari. She used to go to Finland every summer as a guest lecturer and teacher for the Saami,who basically look like what we call Eskimos. Then again,Eskimos look like Asians. Since they are,that kind of works out.
If you see a Mari that looks Asian,think "Mongul hordes descendant" from the time the Mongols controlled Russia. Seeing one with red or blonde hair means there has been a ethnic Russian in the woodpile,and truly most today look like Russians. Ironically enough,my friend Natalia looked Slavic even though she was half-Mari. Her husband Vladimir died several years ago and I lost contact with her. I suspect she has probably died by now. They had no children.
I know nothing about Estonian Mari,but there was a big tribe in Hungary,and some of them may have migrated to Estonia to be closer to the sea and fishing.
BTW,if I ever get my breathing back under control and my knees fixed,I plan on making a trip to Hungary. I have a theory that the red-headed Scots are closely related to the redheads that populated the Belgrade area in ancient history,and they are both related to or the direct offspring of the Picts of ancient Scotland,and that they are all originated in northern Spain and the Basques. Same with the redheaded people of Ireland,of course.
I strongly suspect it was these people who were found buried in the desert in China back in the 1920's. Most of the graves were plundered long ago,but there are still some being uncovered,and due to the very dry climate,very revealing. One tomb is said to probably be that of a Priestess because of all jewelry entombed with her,but what was most stunning to me is she was buried sitting up in a bed fully clothed from head to toe in black,and she is wearing what would be described as a "Witches Hat" on her head.
She is described as being over 6 feet tall,with long braided red hair running down her back,and green eyes. I think these people were related to the Picts,and were probably ran out of what is now Europe by the Catholic Church,who at one time declared red-headed children to be "the spawn of Satan",which caused a lot of them to be drowned at birth. Nobody has ever seen even a drawing of a Pict,but the Romans that build a big wall to protect themselves from the Picts described them as "fierce giants with red hair that went into battle naked with their bodies painted blue. They flat scared the hell out of the Romans,but for reasons lost to history they just seemed to vanish into thin air,and nobody knows what happened to them.
Personally,I think they bred with the Basque that moved into the area to the point where they as well as the local Basque disappeared as a distinct people,and became the "Highland Scots".
It has been decades since I have given this much thought,and I suspect there has been new information discovered about all these people since then. With the ability we have now to link people by DNA,it would be hard to believe that more isn't known now.