Genealogia Molecular: July 2011

Wednesday, July 20, 2011

Hoy 20 de julio pero del año 1822 nació el austríaco Gregor Johann Mendel

Hoy 20 de julio pero del año 1822 nació el austríaco Gregor Johann Mendel, personaje mejor conocido por sus leyes de la herencia genética. Po ello google le ha dedicado su doodle por sus 189 aniversario.

Mendel fue titular de la prelatura de la Imperial y Real Orden Austriaca del emperador Francisco José I, director emérito del Banco Hipotecario de Moravia, fundador de la Asociación Meteorológica Austriaca, miembro de la Real e Imperial Sociedad Morava y Silesia para la Mejora de la Agricultura, Ciencias Naturales y Conocimientos del País y jardinero (aprendió de su padre cómo hacer injertos y cultivar árboles frutales).

Mendel presentó sus trabajos en las reuniones de la Sociedad de Historia Natural de Brünn3 (Brno) el 8 de febrero y el 8 de marzo de 1865, y los publicó posteriormente como Experimentos sobre hibridación de plantas en 1866 en las actas de la Sociedad. Sus resultados fueron ignorados por completo, y tuvieron que transcurrir más de treinta años para que fueran reconocidos y entendidos.

Al tipificar las características fenotípicas (apariencia externa) de los guisantes las llamó "caracteres". Usó el nombre "elemento" para referirse a las entidades hereditarias separadas. Su mérito radica en darse cuenta de que en sus experimentos (variedades de guisantes) siempre ocurrían en variantes con proporciones numéricas simples.

Los "elementos" y "caracteres" han recibido posteriormente infinidad de nombres, pero hoy se conocen de forma universal con el término genes, que sugirió en 1909 el biólogo danés Wilhem Ludwig Johannsen. Para ser más exactos, las versiones diferentes de genes responsables de un fenotipo particular se llaman alelos. Los guisantes verdes y amarillos corresponden a distintos alelos del gen responsable del color.

Mendel falleció el 6 de enero de 1884 en Brünn, a causa de una nefritis crónica sin tener descendientes directos.

Leyes de la Herencia de Mendel
Las tres leyes descubiertas por Mendel se enuncian como sigue: según la primera, cuando se cruzan dos variedades puras de una misma especie, los descendientes son todos iguales y pueden parecerse a uno u otro progenitor o a ninguno de ellos; la segunda afirma que, al cruzar entre sí los híbridos de la segunda generación, los descendientes se dividen en cuatro partes, de las cuales una se parece a su abuela, otra a su abuelo y las dos restantes a sus progenitores; por último, la tercera ley concluye que, en el caso de que las dos variedades de partida difieran entre sí en dos o más caracteres, cada uno de ellos se transmite de acuerdo con la primera ley con independencia de los demás.

(desde mi SmartPhone)

Benicio Samuel Sanchez
Genealogista e Historiador Familiar

Email: samuelsanchez@genealogia.org.mx
Website: http://www.Genealogia.org.mx
Cell Phone (81) 1667-2480

"Haz tu Arbol Genealogico...El Arbol mas Hermoso de la Creacion"

Por medio de la historia familiar descubrimos el árbol más hermoso de la creación: nuestro árbol genealógico. Sus numerosas raíces se remontan a la historia y sus ramas se extienden a través de la eternidad. La historia familiar es la expresión extensiva del amor eterno; nace de la abnegación y provee la oportunidad de asegurarse para siempre una unidad familiar".
(Élder J. Richard Clarke, Liahona julio de 1989, pág.69)

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Friday, July 15, 2011

Ugo Perego is the speaker in this DNA Webinar

If you are interested in Genetree.com, the Legacy Family Tree Webinar with Ugo Perego is now archived from July 13, 2011

http://www.millenniacorp.com/_videos/webinars/2011-07-13-dna/2011-07-13-dna.html

(desde mi SmartPhone)

Monday, July 04, 2011

New Report on Maria Ines Rodriguez mtDNA

I have DNA test results.

Not the criminal evidence or disease identification type.

I have genetic genealogy DNA test results. Some years ago I had my y-DNA tested. You can see those test results along with hundreds of others posted on "Genealogy of Mexico DNA Surname Project" web site http://garyfelix.tripod.com/index63.htm

The test reveals that my y-DNA came from some European in the distant pass. Look at the summary pie chart of Mexican y-DNA on the web site and find the y-DNA distribution of people claiming Mexican roots today is made up of 79% Spanish, 13% Native American and 8% African. That is my simplification of what is actually presented. The page has 49% Western European, 23% Semitic, 7% Nordic, 13% Native American and 8% Miscellaneous. Iberian history and archaeology explains why Spaniards are a mixture of Western European, Semitic (A family of languages that includes Hebrew, Arabic, Aramaic, and certain ancient languages such as Phoenician and Akkadian.) and Nordic (Relating to Scandinavia, Finland, and Iceland.) African slaves brought to Mexico in very large numbers explains the 8% figure for them. What is hard to fathom is that in 490 years since the conquest of Mexico the Native American y-DNA level in Mexico dropped from 100% to 13%. I read somewhere that there were 6 million people living in Mexico at the time of the conquest. Where did all that y-DNA go?

This year I decided to get my mtDNA tested. This after making a presentation last year at a SHHAR meeting on the subject of Mexican mtDNA testing. I decided to test with FamilyTreeDNA for a number of reasons, the primary reason being that they have a large Mexican mtDNA project. They have test results for hundreds of people with Mexican roots posted.

http://www.familytreedna.com/public/GenealogyofMexicoDNAProject/default.aspx?section=mtresults

I ran the numbers from that site and found 77% Native American, 17% European (Spanish), 5% African and 1% Asian. I think these numbers are easier to swallow.

As I swabbed the inside of my cheek for a test sampled, I wondered to which Native American haplogroup I belonged. After all, the odds favored my results would be Native American. I rushed to embrace the idea of belonging to any one of the Native American haplogroups which are A, B, C, D and the rare X. You cannot pick your mtDNA test results. The results came back as haplogroup K. It took a while to accept it but I have come to love it. Let me tell you why I find my test results so special. Some time ago I persuaded Rosalinda Cantu to get mtDNA tested because my genealogy database identified her as an mtDNA descendant of Maria Ines Rodriguez.

I have over 70,000 descendants of Maria Ines in my database. She is at the top of my database top ten list of mtDNA haplotypes. My test results match those of Rosalinda Cantu. That means that I probably have my mtDNA by way of Maria Ines Rodriguez. Unlike Rosalinda, I have not been able to trace my mtDNA line back to Maria Ines. I trace my mtDNA line back seven generations. I would have to add another maybe ten generations to reach Maria Ines. These test results may have bridged that generational gap for me.

What do these tests results tell me about who I am? Both reveal Spanish ancestors. They confirm one male and one female ancestor had roots in Europe (Spain?). That is a far cry from the whole picture. Starting from me as generation one and going back eleven generations I would have 1,024 ancestors (612 male and 612 female) that generation alone. One of those males and one of those females carried the same y-DNA and mtDNA as me. My test results tell me nothing of my other 1,022 ancestors. The numbers from the Mexican Surname DNA site may give a truer picture of my genome. Why not use the numbers from that site to predict my genetic mixture. If I could test my 612 male ancestors, I might predict 483 Spaniard, 80 Native American and 49 African. If I could test my 612 female ancestors the numbers could be 471 Native American, 104 Spaniard and 37 African. I like that.

I have an email from a person matching my mtDNA asking how to interpret the results.

One way to think about it is that my mtDNA came from my mother who got it from her Mexican mother who got it from her Mexican mother etc. until we arrive at a mother who sailed across the ocean from Spain bringing a new mtDNA to the Mexico. That mtDNA spread to be the largest haplotype in my records. I have posted a report showing how over 3,000 females carry the same mtDNA as Maria Ines Rodriguez. (See the link below)

My records show that I descend from Maria Ines Rodriguez, 34 ways, by way of three of her daughters; Beatriz, Ines and Mariana Navarro.

I descend from Beatriz Navarro 1 way, Ines Navarro 14 ways and Mariana Navarro 19 ways. Coincidentally, of the four people in my database that trace back to Maria Ines Rodriguez on their mtDNA line, all have matching HVR1 mtDNA test results on FamilyTreeDNA. The two people that trace back to Mariana Navarro do so from different daughters. I used different color highlighting on the report to make it easier to follow how the lines descend.

Female mtDNA Descendants of Maria Ines Rodriguez

http://home.earthlink.net/~crisrendon/mariainesrodriguez.pdf

Best Regards,

Crispin Rendon

(desde mi SmartPhone)