In a groundbreaking development in the field of anti-acne therapies, a team of researchers at University of California San Diego School of Medicine has created an acne vaccine that successfully reduces inflammation in a mouse ...
Jan 5, 2024
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The large, capable human brain is a marvel of evolution, but how it evolved from a smaller primate brain into the creative, complex organ of today is a mystery. Scientists can pinpoint 'when' our evolutionary ancestors evolved ...
Dec 11, 2023
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In 1802, Ludwig van Beethoven asked his brothers to request that his doctor, J. A. Schmidt, describe his malady—his progressive hearing loss—to the world upon his death so that "as far as possible at least the world will ...
Mar 22, 2023
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There is no stronger risk factor for cancer than age. At the time of diagnosis, the median age of patients across all cancers is 66. That moment, however, is the culmination of years of clandestine tumor growth, and the answer ...
Mar 4, 2021
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Music has been a part of humanity for as long as humanity has existed. Archeologists have unearthed relatively complex bone instruments greater than 40,000 years old. Certainly, human ancestors likely were making music in ...
Dec 29, 2020
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An international group of researchers has tackled the controversial question of when measles first emerged, finding it could be linked to the rise of large cities. The team sequenced the genome of a measles strain from 1912 ...
Jun 18, 2020
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(HealthDay)—More evidence has surfaced that the COVID-19 coronavirus was circulating in the United States as much as a month prior to the first confirmed local case in February, the U.S. Centers for Disease Control and ...
Jun 1, 2020
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Scientists have discovered an earlier origin to the human language pathway in the brain, pushing back its evolutionary origin by at least 20 million years.
Apr 20, 2020
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Researchers have provided new insight on why some genes that formed during the evolution of the earliest animals on earth are particularly impaired (or dysregulated) by specific mechanisms during cancer development.
Feb 26, 2019
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Our ability to selectively forget distracting memories is shared with other mammals, suggests new research from the University of Cambridge. The discovery that rats and humans share a common active forgetting ability—and ...
Nov 7, 2018
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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.
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