Monday, September 17, 2018

Monday Information in Mid-September 2018.



In our generation, more and more people are studying genealogy. Learning about our ancestors certainly is interesting and makes us aware of the common bonds that we have as human beings. Nothing is new under the sun. So, our forefathers and our foremothers had the same emotions, the same yearnings for justice, and the same motivation to enact action as we do in our time near 2020. Recently, I have investigated much of my ancestry and I have certainly made incredible discoveries. I discovered distant cousins that I didn’t know and I knew of many ancestors who made an incredible impact on American history. For example, my 3rd great-grandfather Johnson Brickhouse was born in 1826 and he was a man who fought on the Union side of the Civil War. Also, my fifth great-grandmother was Zilphy Claud (1820-1893) of Southampton County, Virginia. She was born a slave and lived to see the end of slavery in witnessing her children and her grandchildren. My mother told me stories about a man named Arthur Boss Claud (1891-1974), who is my second great-grandfather. He was a short man and a famous man of Southampton County. My father talked about my second great-grandmother Esther Brickhouse Bailey (1862-1955) too. She was born a slave and lived to see freedom. She lived in Northampton County, Virginia. So, I have been blessed enough to know a lot about my ancestors. Today is the time to show more information not only on DNA, but on my family history on my father’s side and on my mother’s side. Haplogroups and other components of genealogical research are very important. As technology develops, even more millions of human beings will get DNA tests in figuring out their genetic ancestral story.


DNA stands for deoxyribonucleic acid. DNA in essence is a molecule made up of 2 chains (made up of nucleotides) that coil around each other to form a double helix. DNA carries the genetic instructions used in the growth, development, functioning, and reproduction of all known living organism and many viruses. The instructions dealing with life is encoded in DNA. DNA is organized into pieces called chromosomes. Then, chromosomes are organized into genes. DNA plus RNA (ribonucleic acid) are nucleic acids. Nucleic acids are one of the four major types of macromolecules that are essential for all known forms of life. The two strands of DNA are called polynucleotides since they are made up of simpler monomeric units called nucleotides. DNA stores biological information. A chromosome is a DNA molecule with part or all of the genetic material (genome) or an organism. Chromosomes are made up of chromatin fiber. So, you have a cell. In the middle of the cell is the nucleus. Part of the nucleus is the chromosome and a chromosome is made up of DNA. The unit of DNA packaging in eukaryotes (i.e. any organism have cells with a nucleus enclosed with membranes. Humans therefore are eukaryotes. Conversely, prokaryotes are bacteria and archaea) is called the nucleosome. So, genetic information is held in DNA via genes. The genetic information in a genome is held within genes and the complete set of this information in an organism is called the genotype. A gene is a unit of heredity and is a region of DNA that influences the characteristics of an organism. The genotype represents the genetic makeup of a cell. The genotype influences the phenotype. A phenotype results from the expression of an organism's genetic code, its genotype, as well as the influence of environmental factors and the interactions between the two. The phenotype is an organism’s observable characteristics or traits like morphology, development, biochemical, or physiological properties. For example, black hair or dark skin is a phenotype. Also, the egg and sperm are necessary to create human life. They have only 23 chromosomes each in humans. A sperm from a man and an egg from a woman combine to create the zygote (via fertilization. The sperm binds with the eggs and fuses the gametes to form a new organism. One cell divides constantly and ends up with a human life). Sperm cells have an X and a Y while egg cells can only have an X. The zygote has 46 chromosomes and grows into a baby. This process of the sperm and the egg merging into one human with the DNA is called meiosis. In genetics, all of our chromosomes are inherited from both of our parents. Genes can dictate our characteristics. For example, if you have long arms, then the genes inherited from your parents will instruct your body to have long arms. Genes have proteins to do functions like giving cells shape, digesting foods, and carrying oxygen in the blood. By about 60,000-70,000 years ago, modern day Homo sapiens sapiens lived in all over Africa started to travel into the world beyond Africa as well.


A lot of people don’t know what haplogroups mean. In genetic testing, haplogroups are discussed all of the time. What is a haplogroup? A haplogroup is a genetic population group who share a common ancestor on the patrilineal or the matrilineal line. Researchers give haplogroups assigned letters of the alphabet and refinements are made up of additional number and letter combinations. Haplogroups have shared genetic variation. So, a haplogroup is like a signal of your genetic ancestry. A haplogroup is made up of similar haplotypes. A haplotype is a DNA signature that is made up of markets on a single chromosome that the end to be inherited together. In other words, a haplotype is a group of genes in an organism that are inherited together from a single parent. A haplogroup is a group of similar haplotypes that share a common ancestor with a single-nucleotide polymorphism mutation. More specifically, a haplogroup is a combination of alleles at different chromosomes regions that are closely linked and that tend to be inherited together. Each letter and number in a haplogroup corresponds to a set of defining mutations in our mitochondrial DNA and our Y-chromosome. Some letter and number combinations define a mark when a population first migrated out of Africa or when another group was geographically isolated. 

The maternal haplogroups (mtDNA) are determined by defining variants in your own mitochondrial DNA. Everyone inherits their mitochondria from our mothers. Our mtDNA is the only type of DNA that is found outside of the nucleus. That is why it doesn’t recombine with other types of DNA. Our mitochondria is inherited directly from our mothers and undergoes very little recombination. We share maternal hapologroup with any relative you share a direct maternal line with. So, our mothers, our brothers, our sisters, our maternal aunts, our maternal grandmother, etc. would share the same maternal haplogroup. Maternal hapologroup goes back through the generations to a single mutation at a specific place and time. Human mtDNA haplogroups are lettered: A, B, C, CZ, D, E,F, G, H, HV, I, J, pre-JT, JT, K, L0, L1, L2, L3, L4, L5, L6,M, N, P, Q, R, R0, S, T, U, V, W, X, Y, and Z. The most up-to-date version of the mtDNA tree is maintained by Mannis van Oven on the PhyloTree website. mtDNA hapologroups in Africa include L0, L1, L2, L3, L4, L5, and L6. 

The paternal haplogroup (Y-DNA) is determined by defining variants in our Y-Chromosome. The Y chromosome is the sex determining chromosome for males, which means men inherit it from our fathers. I am a man, so I inherited by my Y-chromosome from my father and I have a paternal haplogroup situation. The Y chromosome does have recombination with the X-chromosome, but it only does it at the end. About 95% of the Y chromosome remains intact relatively across generations. The Y chromosome is a reflection of our paternal ancestry. Human Y chromosome DNA (Y-DNA) haplogroups are named from A to T, and are further subdivided using numbers and lower case letters. Y chromosome haplogroup designations are established by the Y Chromosome Consortium. Haplogroup E-V38 is a human Y-chromosome DNA haplogroup. It is primarily distributed in Africa. E-V38 has two basal branches, E-M329 (formerly E1b1c or E1b1*) and E-M2 (formerly E1b1a).


By Timothy


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