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Chimpanzees Branch Off (CHLCA)

By Michael Alan Prestwood

Sun 27 Jun 2021
Published 5 years ago.
Updated 2 weeks ago.
The Branch That Made Us: The CHLCA
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Chimpanzees Branch Off (CHLCA)

7.5 Million Years Ago
Advanced coalition politics and tool precursors
300,000 Generations Ago (from 2020 CE)

Hominini Tribe: The last common ancestor with humans and the pan genus (chimpanzees and bonobos) lived around 7.5 mya. This branch of pan splits again about 1.5 mya into two species: chimpanzees and bonobos.

Humans did not evolve from Chimpanzees, but both are the current evolution of a common ancestor. That common ancestor has yet to be identified and is sometimes referred to as the Chimpanzee–Human Last Common Ancestor (CHLCA). That ancestor lived in Africa about 7.5 million years ago, likely in East Africa or perhaps Central Africa. The genus that is perhaps the most likely for the CHLCA is Sahelanthropus. While much of Africa today features arid deserts, Western Africa and at least parts of Central Africa and Eastern Africa were rainforests and tropical forests during this key time of early hominin evolution.

CHLCA likely lived sometime between 5 and 9 million years ago, with 7.5 million years ago being a common educated estimate. Sahelanthropus tchadensis, and other later Hominini tribe descendants, supports estimates placing the CHLCA at about 7.5 million years ago. For example, Sahelanthropus tchadensis survived from 7 to 6 million years ago in Central Africa.

Primary Timeline…

Analysis: The descendants of CHLCA are known collectively as the Hominini tribe within the larger Hominidae family. Today this tribe includes only humans, the common chimpanzee, and bonobos. Did you notice that I said CHLCA is not part of the Hominini tribe? Interestingly, scientists so far have excluded the ultimate founder of the Hominini tribe. Tribes are defined by common characteristics and because we have yet to find a CHLCA, they are left out. Since all known descendants of CHLCA, living and extinct, have the common characteristics that define the Hominini tribe, so did CHLCA. Well, that’s what I think at least. For more on why the simplest explanation gets this kind of weight in analysis, check out my Occam’s Razor: Simplifying Complexity article.

— map / TST —

Michael Alan Prestwood
Author & Natural Philosopher
Prestwood writes on science-first philosophy, with particular attention to the convergence of disciplines. Drawing on his TST Framework, his work emphasizes rational inquiry grounded in empirical observation while engaging questions at the edges of established knowledge. With TouchstoneTruth positioned as a living touchstone, this work aims to contribute reliable, evolving analysis in an emerging AI era where the credibility of information is increasingly contested.
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