Woolly mammoths and Neanderthals may have shared genetic traits

A new Tel Aviv University study suggests that the genetic profiles of two extinct mammals with African ancestry—woolly mammoths, elephant-like animals that evolved in the arctic peninsula of Eurasia around 600,000 years ...

Alligator study reveals insight into dinosaur hearing

To determine where a sound is coming from, animal brains analyze the minute difference in time it takes a sound to reach each ear—a cue known as interaural time difference. What happens to the cue once the signals get to ...

Ancient DNA research shines spotlight on Iberia

The largest study to date of ancient DNA from the Iberian Peninsula (modern-day Portugal and Spain) offers new insights into the populations that lived in this region over the last 8,000 years. The most startling discovery ...

A future for red wolves may be found on Galveston Island

Red wolves, once nearly extinct, again teeter on the abyss. New research finds red wolf ancestry on Galveston Island—providing opportunities for additional conservation action and difficult policy challenges.

Modern humans interbred with Denisovans twice in history

Modern humans co-existed and interbred not only with Neanderthals, but also with another species of archaic humans, the mysterious Denisovans. While developing a new genome-analysis method for comparing whole genomes between ...

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Ancestor

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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