Post by djoser-xyyman on Mar 19, 2019 13:31:27 GMT -5
1. Mediterranean Hominins: Older or Clever than Usually Thought?
The oldest (ca. 2.6 Ma) stone tools associated with butchery practiced by hominins known to date
are from East Africa (Olduvai, Tanzania). According to the available evidence, this technology did not
appear in the Mediterranean area of northern Africa until 1.8 Ma (Ain Hanech, Algeria), after hominin
dispersal from East Africa. However, Sahnouni et al. [1] reported stone artifacts and cutmarked bones
as old as ca. 2.4 Ma from another Algerian locality (Ain Boucherit), which is the oldest evidence of
hominin butchery from the Mediterranean region. According to the authors, this new evidence
suggests that either East-African butchery technology—and, hence, part of the oldest East-African
hominins—migrated to the Mediterranean region much earlier than previously thought or,
alternatively, the same stone technology originated independently in both East and North Africa, at
similar times.
4. Are We Losing Neandertal Ancestry?
It has been estimated that up to 2% of the genome from present-day non-African humans is of
Neandertal origin as a consequence of interbreeding between modern humans and Neandertals that
occurred ca. 55,000 years ago. It has also been suggested that the amount of Neandertal DNA in modern
humans was higher after the initial interbreeding and has progressively been reduced by negative
selection due to deleterious introgression. Petr et al. [4] reexamined estimates of Neandertal ancestry in
ancient and present-day modern humans and found no evidence for long-term genome-wide removal
of Neandertal DNA. The authors consider that previous results were an artifact resulting from the
failure to consider gene flow between West Eurasian and African modern human populations.
Selection against Neandertal ancestry has occurred primarily on non-coding DNA, suggesting that
Neandertals may have differed from modern humans in their regulatory variants, rather than in
protein-coding sequences
The oldest (ca. 2.6 Ma) stone tools associated with butchery practiced by hominins known to date
are from East Africa (Olduvai, Tanzania). According to the available evidence, this technology did not
appear in the Mediterranean area of northern Africa until 1.8 Ma (Ain Hanech, Algeria), after hominin
dispersal from East Africa. However, Sahnouni et al. [1] reported stone artifacts and cutmarked bones
as old as ca. 2.4 Ma from another Algerian locality (Ain Boucherit), which is the oldest evidence of
hominin butchery from the Mediterranean region. According to the authors, this new evidence
suggests that either East-African butchery technology—and, hence, part of the oldest East-African
hominins—migrated to the Mediterranean region much earlier than previously thought or,
alternatively, the same stone technology originated independently in both East and North Africa, at
similar times.
4. Are We Losing Neandertal Ancestry?
It has been estimated that up to 2% of the genome from present-day non-African humans is of
Neandertal origin as a consequence of interbreeding between modern humans and Neandertals that
occurred ca. 55,000 years ago. It has also been suggested that the amount of Neandertal DNA in modern
humans was higher after the initial interbreeding and has progressively been reduced by negative
selection due to deleterious introgression. Petr et al. [4] reexamined estimates of Neandertal ancestry in
ancient and present-day modern humans and found no evidence for long-term genome-wide removal
of Neandertal DNA. The authors consider that previous results were an artifact resulting from the
failure to consider gene flow between West Eurasian and African modern human populations.
Selection against Neandertal ancestry has occurred primarily on non-coding DNA, suggesting that
Neandertals may have differed from modern humans in their regulatory variants, rather than in
protein-coding sequences