Human Origins: Difference between revisions

Line 1:

== ~~Question~~ ==

''Written by AI. Help improve this answer by adding to the sources section. When the sources section is updated this article will regenerate.''

=== Summary ===

Current evidence indicates that Homo sapiens evolved in Africa between roughly 300 000 and 200 000 years ago. Rather than arising in a single, isolated population, the species seems to have been shaped by interaction among several semi-independent populations spread across the continent, followed by expansions out of Africa and limited gene flow with Eurasian archaic groups such as Neanderthals and Denisovans [1] [2].

=== Genetic and Fossil Evidence ===

* Fossil remains at Jebel Irhoud (Morocco, ~300 ka) and Omo Kibish (Ethiopia, ~195 ka) display mixtures of modern and archaic traits, implying that “modern” morphology emerged gradually in different regions of Africa [1].

* Genome-wide analyses of present-day and ancient African DNA reveal deep population structure dating back >300 ka. These data are better explained by a network of populations exchanging migrants than by one isolated cradle [1].

* Outside Africa, all living non-African humans share evidence of at least one expansion beginning ~70 ka, accompanied by introgression from Neanderthals (1–2 % of the genome) and, in some regions, Denisovans (up to 5 %) [2].

=== Major Scientific Models ===

Recent African Origin (RAO) – Homo sapiens evolved in Africa and later replaced local Eurasian hominins except for limited admixture. This remains the core narrative for most geneticists [2].

Pan-African Network – Modern humans arose within a structured metapopulation that stretched across Africa; no single region exclusively holds the “origin” [1].

Extended Multiregionalism within Africa – A minority view emphasises near-continuous gene flow across Africa and Eurasia over the last million years. It has little direct genomic support and is not defended by either cited author.

=== Points of Consensus ===

* Africa is the primary geographic source of anatomically modern humans [1] [2].

* All present-day non-Africans descend mainly from a late Pleistocene expansion out of Africa [2].

* Admixture with Neanderthals and Denisovans occurred after that expansion [2].

=== Points of Disagreement ===

* How many ancestral populations within Africa contributed substantially to later humans?

– Nature study argues for at least three long-standing lineages exchanging migrants [1].

– Razib Khan accepts deep structure but stresses that available data cannot yet resolve whether there were “three, six, or a dozen” such groups [2].

* Timing and rate of gene flow among those African lineages.

– The Nature authors model continuous, low-level exchange [1].

– Khan notes alternative models with pulses of admixture also fit current data [2].

=== Timeline of the Public Discourse ===

1920s–1960s – Fossil discoveries feed the “single origin” (East Africa) vs. “multiregional” debate centred on morphology.

1987 – Mitochondrial-DNA “Eve” paper popularises a recent African origin.

1997–2010 – Ancient DNA confirms Neanderthals as a sister group; Neanderthal genome (2010) reveals admixture with modern humans, refining RAO rather than overthrowing it.

2017 – Jebel Irhoud fossils extend modern-looking traits back to 300 ka, raising interest in a pan-African scenario.

2020s – High-coverage genomes from understudied African populations and improved modelling lead to the metapopulation/pan-African synthesis promoted in the 2025 Nature study [1]. Blogs and podcasts (e.g., Razib Khan, 2024) stress the remaining “it’s complicated” aspects [2].

=== Remaining Open Questions ===

* Which specific regions in Africa hosted the main ancestral lineages?

* How did climatic oscillations regulate connectivity among African populations?

* What is the precise contribution of yet-unsampled archaic African hominins?

~~What is~~ the ~~origin of the human species?~~

Ongoing fieldwork and ancient-DNA retrieval from tropical contexts are expected to clarify these issues over the next decade.

== Sources ==

# https://www.nature.com/articles/s41588-025-02117-1

# https://www.razibkhan.com/p/current-status-its-complicated

== Question ==

What is the origin of the human species?

@@ Line 1: / Line 1: @@
-== Question ==
+''Written by AI. Help improve this answer by adding to the sources section. When the sources section is updated this article will regenerate.''
+=== Summary   ===
+Current evidence indicates that Homo sapiens evolved in Africa between roughly 300 000 and 200 000 years ago. Rather than arising in a single, isolated population, the species seems to have been shaped by interaction among several semi-independent populations spread across the continent, followed by expansions out of Africa and limited gene flow with Eurasian archaic groups such as Neanderthals and Denisovans [1] [2].
+=== Genetic and Fossil Evidence   ===
+* Fossil remains at Jebel Irhoud (Morocco, ~300 ka) and Omo Kibish (Ethiopia, ~195 ka) display mixtures of modern and archaic traits, implying that “modern” morphology emerged gradually in different regions of Africa [1].
+* Genome-wide analyses of present-day and ancient African DNA reveal deep population structure dating back >300 ka. These data are better explained by a network of populations exchanging migrants than by one isolated cradle [1].
+* Outside Africa, all living non-African humans share evidence of at least one expansion beginning ~70 ka, accompanied by introgression from Neanderthals (1–2 % of the genome) and, in some regions, Denisovans (up to 5 %) [2].
+=== Major Scientific Models   ===
+Recent African Origin (RAO)  – Homo sapiens evolved in Africa and later replaced local Eurasian hominins except for limited admixture. This remains the core narrative for most geneticists [2].
+Pan-African Network  – Modern humans arose within a structured metapopulation that stretched across Africa; no single region exclusively holds the “origin” [1].
+Extended Multiregionalism within Africa  – A minority view emphasises near-continuous gene flow across Africa and Eurasia over the last million years. It has little direct genomic support and is not defended by either cited author.
+=== Points of Consensus   ===
+* Africa is the primary geographic source of anatomically modern humans [1] [2].
+* All present-day non-Africans descend mainly from a late Pleistocene expansion out of Africa [2].
+* Admixture with Neanderthals and Denisovans occurred after that expansion [2].
+=== Points of Disagreement   ===
+* How many ancestral populations within Africa contributed substantially to later humans?
+  – Nature study argues for at least three long-standing lineages exchanging migrants [1].
+  – Razib Khan accepts deep structure but stresses that available data cannot yet resolve whether there were “three, six, or a dozen” such groups [2].
+* Timing and rate of gene flow among those African lineages.
+  – The Nature authors model continuous, low-level exchange [1].
+  – Khan notes alternative models with pulses of admixture also fit current data [2].
+=== Timeline of the Public Discourse   ===
+s–1960s – Fossil discoveries feed the “single origin” (East Africa) vs. “multiregional” debate centred on morphology.
+– Mitochondrial-DNA “Eve” paper popularises a recent African origin.
+–2010 – Ancient DNA confirms Neanderthals as a sister group; Neanderthal genome (2010) reveals admixture with modern humans, refining RAO rather than overthrowing it.
+– Jebel Irhoud fossils extend modern-looking traits back to 300 ka, raising interest in a pan-African scenario.
+s – High-coverage genomes from understudied African populations and improved modelling lead to the metapopulation/pan-African synthesis promoted in the 2025 Nature study [1]. Blogs and podcasts (e.g., Razib Khan, 2024) stress the remaining “it’s complicated” aspects [2].
+=== Remaining Open Questions   ===
+* Which specific regions in Africa hosted the main ancestral lineages?
+* How did climatic oscillations regulate connectivity among African populations?
+* What is the precise contribution of yet-unsampled archaic African hominins?
-What is the origin of the human species?
+Ongoing fieldwork and ancient-DNA retrieval from tropical contexts are expected to clarify these issues over the next decade.
 == Sources ==
 # https://www.nature.com/articles/s41588-025-02117-1
 # https://www.razibkhan.com/p/current-status-its-complicated
+== Question ==
+What is the origin of the human species?