The Middle Pleistocene (~721-126 thousand-years-ago) is one of the most complex and unclear perio... more The Middle Pleistocene (~721-126 thousand-years-ago) is one of the most complex and unclear periods with regards to the evolutionary history of genus Homo. Remains from Africa, Europe, and sometimes Asia are assigned to “Homo heidelbergensis”: a species theoretically defined around the ~600,000-year-old Mauer mandible. However, many specimens do not align closely with the holotype, and the apparently-broad polymorphism during this period, combined with the emergence of modern human, Neanderthal, and Denisovan lineages have made the designation H. heidelbergensis extremely controversial.
A geometric-morphometric analysis of posterior dental crowns was undertaken, with the aim of quantifying and assessing levels of intra-specific shape variability within H. heidelbergensis in comparison with other taxa. The results showed that Middle Pleistocene specimens generally exhibited larger inter-individual shape variation than other hominin species and may include several palaeodemes, providing further support to the illegitimacy of H. heidelbergensis. However, it may not necessarily be concluded from this study that the specimens represent more than one broad, over-arching species; at least, within this sample of mostly-European specimens. Alternatively, it may provide support for broad intra-taxic variability, and leaves the status of H. heidelbergensis still to be clarified. Though many interpretations of H. heidelbergensis are found in palaeoanthropological literature, it may not necessarily be inaccurate as a cross-continental species lasting from ~700kya until speciation events, ~250kya.
The addition of Afro-Eurasian specimens would provide a fairer assessment of H. heidelbergensis as a cross-continental taxon. Furthermore, this study adds to the lack of clarity with regards to acceptable levels of polymorphism within the genus Homo.
Many species co-existed with Homo sapiens in the Late Pleistocene. Through morphological and pala... more Many species co-existed with Homo sapiens in the Late Pleistocene. Through morphological and palaeo-genomic analysis, four archaic hominins have been proven to have interbred with modern humans. Findings show that modern humans of Eurasian origin share DNA with Neanderthals. Additionally, Melanesians, share archaic haplotypes with Neanderthals but also Denisovans and an unknown group, “Species X”, whilst African populations share many with an archaic group of H. sapiens. Introgressed haplotypes of archaic origin are located within many coding sections of DNA, some at curiously high frequencies within certain populations. This can be explained through positive selective pressure, indicating that interbreeding was often adaptive. However, interbreeding also had some detrimental impacts on modern humans (e.g. infertility), which is likely a reason why there is not a greater number of archaic lineages present in modern DNA.
Genetic data allows mapping of the date, location and frequency of admixture events. This contextualisation indicates that - to some extent - an assimilation model is the best fit for the “extinction” of Late Pleistocene hominin species. Therefore, it could be argued that these species are not truly extinct, and instead they live on within modern humans, as nearly 10% of some modern genomes being made up of introgressed sequences. Evidence of introgression suggests it is highly probable that admixture has been a critical dynamic in the process hominin evolution, ever since the origin of our lineage. This has numerous implications on the dynamics of interactions between hominin groups, but also on the designation of many hominin populations as species in their own right.
The Middle Pleistocene (~721-126 thousand-years-ago) is one of the most complex and unclear perio... more The Middle Pleistocene (~721-126 thousand-years-ago) is one of the most complex and unclear periods with regards to the evolutionary history of genus Homo. Remains from Africa, Europe, and sometimes Asia are assigned to “Homo heidelbergensis”: a species theoretically defined around the ~600,000-year-old Mauer mandible. However, many specimens do not align closely with the holotype, and the apparently-broad polymorphism during this period, combined with the emergence of modern human, Neanderthal, and Denisovan lineages have made the designation H. heidelbergensis extremely controversial.
A geometric-morphometric analysis of posterior dental crowns was undertaken, with the aim of quantifying and assessing levels of intra-specific shape variability within H. heidelbergensis in comparison with other taxa. The results showed that Middle Pleistocene specimens generally exhibited larger inter-individual shape variation than other hominin species and may include several palaeodemes, providing further support to the illegitimacy of H. heidelbergensis. However, it may not necessarily be concluded from this study that the specimens represent more than one broad, over-arching species; at least, within this sample of mostly-European specimens. Alternatively, it may provide support for broad intra-taxic variability, and leaves the status of H. heidelbergensis still to be clarified. Though many interpretations of H. heidelbergensis are found in palaeoanthropological literature, it may not necessarily be inaccurate as a cross-continental species lasting from ~700kya until speciation events, ~250kya.
The addition of Afro-Eurasian specimens would provide a fairer assessment of H. heidelbergensis as a cross-continental taxon. Furthermore, this study adds to the lack of clarity with regards to acceptable levels of polymorphism within the genus Homo.
Many species co-existed with Homo sapiens in the Late Pleistocene. Through morphological and pala... more Many species co-existed with Homo sapiens in the Late Pleistocene. Through morphological and palaeo-genomic analysis, four archaic hominins have been proven to have interbred with modern humans. Findings show that modern humans of Eurasian origin share DNA with Neanderthals. Additionally, Melanesians, share archaic haplotypes with Neanderthals but also Denisovans and an unknown group, “Species X”, whilst African populations share many with an archaic group of H. sapiens. Introgressed haplotypes of archaic origin are located within many coding sections of DNA, some at curiously high frequencies within certain populations. This can be explained through positive selective pressure, indicating that interbreeding was often adaptive. However, interbreeding also had some detrimental impacts on modern humans (e.g. infertility), which is likely a reason why there is not a greater number of archaic lineages present in modern DNA.
Genetic data allows mapping of the date, location and frequency of admixture events. This contextualisation indicates that - to some extent - an assimilation model is the best fit for the “extinction” of Late Pleistocene hominin species. Therefore, it could be argued that these species are not truly extinct, and instead they live on within modern humans, as nearly 10% of some modern genomes being made up of introgressed sequences. Evidence of introgression suggests it is highly probable that admixture has been a critical dynamic in the process hominin evolution, ever since the origin of our lineage. This has numerous implications on the dynamics of interactions between hominin groups, but also on the designation of many hominin populations as species in their own right.
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A geometric-morphometric analysis of posterior dental crowns was undertaken, with the aim of quantifying and assessing levels of intra-specific shape variability within H. heidelbergensis in comparison with other taxa. The results showed that Middle Pleistocene specimens generally exhibited larger inter-individual shape variation than other hominin species and may include several palaeodemes, providing further support to the illegitimacy of H. heidelbergensis. However, it may not necessarily be concluded from this study that the specimens represent more than one broad, over-arching species; at least, within this sample of mostly-European specimens. Alternatively, it may provide support for broad intra-taxic variability, and leaves the status of H. heidelbergensis still to be clarified. Though many interpretations of H. heidelbergensis are found in palaeoanthropological literature, it may not necessarily be inaccurate as a cross-continental species lasting from ~700kya until speciation events, ~250kya.
The addition of Afro-Eurasian specimens would provide a fairer assessment of H. heidelbergensis as a cross-continental taxon. Furthermore, this study adds to the lack of clarity with regards to acceptable levels of polymorphism within the genus Homo.
Genetic data allows mapping of the date, location and frequency of admixture events. This contextualisation indicates that - to some extent - an assimilation model is the best fit for the “extinction” of Late Pleistocene hominin species. Therefore, it could be argued that these species are not truly extinct, and instead they live on within modern humans, as nearly 10% of some modern genomes being made up of introgressed sequences. Evidence of introgression suggests it is highly probable that admixture has been a critical dynamic in the process hominin evolution, ever since the origin of our lineage. This has numerous implications on the dynamics of interactions between hominin groups, but also on the designation of many hominin populations as species in their own right.
A geometric-morphometric analysis of posterior dental crowns was undertaken, with the aim of quantifying and assessing levels of intra-specific shape variability within H. heidelbergensis in comparison with other taxa. The results showed that Middle Pleistocene specimens generally exhibited larger inter-individual shape variation than other hominin species and may include several palaeodemes, providing further support to the illegitimacy of H. heidelbergensis. However, it may not necessarily be concluded from this study that the specimens represent more than one broad, over-arching species; at least, within this sample of mostly-European specimens. Alternatively, it may provide support for broad intra-taxic variability, and leaves the status of H. heidelbergensis still to be clarified. Though many interpretations of H. heidelbergensis are found in palaeoanthropological literature, it may not necessarily be inaccurate as a cross-continental species lasting from ~700kya until speciation events, ~250kya.
The addition of Afro-Eurasian specimens would provide a fairer assessment of H. heidelbergensis as a cross-continental taxon. Furthermore, this study adds to the lack of clarity with regards to acceptable levels of polymorphism within the genus Homo.
Genetic data allows mapping of the date, location and frequency of admixture events. This contextualisation indicates that - to some extent - an assimilation model is the best fit for the “extinction” of Late Pleistocene hominin species. Therefore, it could be argued that these species are not truly extinct, and instead they live on within modern humans, as nearly 10% of some modern genomes being made up of introgressed sequences. Evidence of introgression suggests it is highly probable that admixture has been a critical dynamic in the process hominin evolution, ever since the origin of our lineage. This has numerous implications on the dynamics of interactions between hominin groups, but also on the designation of many hominin populations as species in their own right.