News tagged with ancestry
(HealthDay)—Variants of insulin receptor substrate 1 (IRS1) are associated with insulin resistance and metabolic syndrome, but only under particular dietary conditions, according to a study published online ...
Diabetes Apr 28, 2013 | 3 / 5 (2) | 0
Researchers from Dartmouth's Institute for Quantitative Biomedical Sciences (iQBS) and the Center for Genomic Medicine have helped to discover three unique genetic variations that influence body size and obesity in men and ...
Genetics Apr 22, 2013 | not rated yet | 1
The largest genetic search for "obesity genes" in people of African ancestry has led to the discovery of three new regions of the human genome that influence obesity in these populations and others.
Genetics Apr 15, 2013 | not rated yet | 0 |
Humans have between 20,000 and 25,000 genes that carry instructions for assembling the proteins that do the work of cells. Work led by St. Jude Children's Research Hospital found that children who inherit certain variations ...
Cancer Mar 19, 2013 | not rated yet | 0 |
In the largest ever genome-wide association study on myopia, 23andMe, the leading personal genetics company, identified 20 new genetic associations for myopia, or nearsightedness. The company also replicated two known associations ...
Genetics Mar 14, 2013 | not rated yet | 0
For the first time, scientists have discovered that five major psychiatric disorders—autism, attention deficit-hyperactivity disorder, bipolar disorder, major depressive disorder and schizophrenia—share several common ...
Psychology & Psychiatry Feb 27, 2013 | 5 / 5 (1) | 0
Low birth weights are more prevalent among Brazilians with African ancestry and may be attributed to less use of prenatal care facilities and where those ethnic groups live, according to a new study.
Health Feb 26, 2013 | not rated yet | 0
Atrial fibrillation is the most common type of abnormal heart rhythm, affecting 2.5 million Americans. If left undetected or untreated, atrial fibrillation can lead to stroke. Determining who is at increased risk for atrial ...
Cardiology Feb 26, 2013 | not rated yet | 0
(Medical Xpress)—More than 45,000 people of European and Asian ancestry have taken part in a big study to gain a better understanding of the genetics behind the world's most common eye disorder.
Genetics Feb 21, 2013 | 4 / 5 (1) | 0 |
(Medical Xpress)—Scientists have discovered a gene that interferes with the clearance of hepatitis C virus infection. They also identified an inherited variant within this gene, Interferon Lambda 4 (IFNL4), that predicts ...
Genetics Jan 08, 2013 | 5 / 5 (1) | 0 |
(HealthDay)—Investigators have found preliminary evidence that eating red meat and poultry seems to boost the risk of breast cancer in white women—but not black women.
Cancer Nov 02, 2012 | not rated yet | 0
A large international study has identified three new gene variants associated with body mass index (BMI) levels in adults. The scientific consortium, numbering approximately 200 researchers, performed a meta-analysis of 46 ...
Genetics Oct 25, 2012 | 5 / 5 (1) | 0 |
In the largest-ever genetic study of cholesterol and other blood lipids, an international consortium has identified 21 new gene variants associated with risks of heart disease and metabolic disorders. The findings expand ...
Genetics Oct 11, 2012 | 5 / 5 (1) | 0 |
(Medical Xpress)—Researchers from Harvard School of Public Health have found that greater consumption of sugar-sweetened beverages (SSBs) is linked with a greater genetic susceptibility to high body mass index (BMI) and ...
Overweight and Obesity Sep 21, 2012 | 1 / 5 (1) | 2 |
(Medical Xpress)—Researchers at Moffitt Cancer Center and colleagues have published a study describing the greater difficulty in finding matched, unrelated donors for non-Caucasian patients who are candidates for hematopoietic ...
Cancer Sep 11, 2012 | not rated yet | 0 |
An ancestor is a parent or (recursively) the parent of an ancestor (i.e., a grandparent, great-grandparent, great-great-grandparent, and so forth).
Two individuals have a genetic relationship if one is the ancestor of the other, or if they share a common ancestor. In evolutionary theory, species which share an evolutionary ancestor are said to be of common descent. However, this concept of ancestry does not apply to some bacteria and other organisms capable of horizontal gene transfer.
Assuming that all of an individual's ancestors are otherwise unrelated to each other, that individual has 2n ancestors in the nth generation before him and a total of about 2g+1 ancestors in the g generations before him. In practice, however, it is clear that the vast majority of ancestors of humans (and indeed any other species) are multiply related (see Pedigree collapse). Consider n = 40: the human species is more than 40 generations old, yet the number 240, approximately 1012 or one trillion, dwarfs the number of humans that have ever lived.
Ignoring the possibility of other inter-relationships (even distant ones) among ancestors, an individual has a total of 2046 ancestors up to the 10th generation, 1024 of which are 10th generation ancestors. With the same assumption, any given person has over a billion 30th generation ancestors (who lived roughly 1000 years ago) and this theoretical number increases past the estimated total population of the world in around AD 1000. (All of these ancestors will have contributed to one's autosomal DNA is concerned: this excludes Y-chromosomal DNA and mitochondrial DNA.)
Some cultures confer reverence to ancestors, both living and dead; in contrast, some more youth-oriented cultural contexts display less veneration of elders. In other cultural contexts, some people seek providence from their deceased ancestors; this practice is sometimes known as ancestor worship or, more accurately, ancestor veneration.
For more information about Ancestor, read the full article at
This text uses material from Wikipedia and is available under the GNU Free Documentation License.