A shift in diet has long been seen as one of the critical adaptations that distinguishes our own genus Homo from earlier human ancestors. The timing and context of this dietary shift, however, has been hotly debated. A recent ...
Evolution
Jul 24, 2019
2
457
In pre-Columbian times, the white-tailed deer was among the most abundant and frequently consumed mammals in Panama. It was also an icon, represented on thousands of clay vessels. Through an analysis of deer remains in refuse ...
Archaeology & Fossils
Jul 23, 2019
0
40
Genetic analysis has revealed that the ancestors of modern humans interbred with at least five different archaic human groups as they moved out of Africa and across Eurasia.
Evolution
Jul 15, 2019
7
789
Scientists at the University of Cambridge have uncovered striking similarities in how two distantly related plants defend themselves against pathogens despite splitting from their common ancestor more than 400 million years ...
Plants & Animals
Jul 11, 2019
0
1206
Microbiologists of St Petersburg University, together with researchers from the University of Milan, the University of Pisa, and the University of Pavia, have discovered a new family of bacteria of the order Rickettsiales—Deianiraeaceae. ...
Cell & Microbiology
Jun 14, 2019
0
10
Neanderthals and modern humans diverged at least 800,000 years ago, substantially earlier than indicated by most DNA-based estimates, according to new research by a UCL academic.
Archaeology & Fossils
May 15, 2019
18
1266
Statistical analysis of fossil data shows that it is unlikely that Australopithecus sediba, a nearly two-million-year-old, apelike fossil from South Africa, is the direct ancestor of Homo, the genus to which modern-day humans ...
Archaeology & Fossils
May 08, 2019
1
846
African apes adapted to living on the ground, a finding that indicates human evolved from an ancestor not limited to tree or other elevated habitats. The analysis adds a new chapter to evolution, shedding additional light ...
Evolution
Apr 30, 2019
3
716
In 2015, our Serbian-Canadian archaeological research team was working at a cave site named Pešturina, in Eastern Serbia, where we had found thousands of stone tools and animal bones. One day, an excited Serbian undergrad ...
Archaeology & Fossils
Apr 24, 2019
1
531
What triggered the decline and eventual extinction of many megaherbivores, the giant plant-eating mammals that roamed the Earth millions of years ago, has long been a mystery. These animals, which weighed 1,000kg or more ...
Archaeology & Fossils
Apr 08, 2019
1
15
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 surely 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.
This text uses material from Wikipedia, licensed under CC BY-SA
