scholarly journals Recent origin of low trabecular bone density in modern humans

2014 ◽  
Vol 112 (2) ◽  
pp. 366-371 ◽  
Author(s):  
Habiba Chirchir ◽  
Tracy L. Kivell ◽  
Christopher B. Ruff ◽  
Jean-Jacques Hublin ◽  
Kristian J. Carlson ◽  
...  

Humans are unique, compared with our closest living relatives (chimpanzees) and early fossil hominins, in having an enlarged body size and lower limb joint surfaces in combination with a relatively gracile skeleton (i.e., lower bone mass for our body size). Some analyses have observed that in at least a few anatomical regions modern humans today appear to have relatively low trabecular density, but little is known about how that density varies throughout the human skeleton and across species or how and when the present trabecular patterns emerged over the course of human evolution. Here, we test the hypotheses that (i) recent modern humans have low trabecular density throughout the upper and lower limbs compared with other primate taxa and (ii) the reduction in trabecular density first occurred in early Homo erectus, consistent with the shift toward a modern human locomotor anatomy, or more recently in concert with diaphyseal gracilization in Holocene humans. We used peripheral quantitative CT and microtomography to measure trabecular bone of limb epiphyses (long bone articular ends) in modern humans and chimpanzees and in fossil hominins attributed to Australopithecus africanus, Paranthropus robustus/early Homo from Swartkrans, Homo neanderthalensis, and early Homo sapiens. Results show that only recent modern humans have low trabecular density throughout the limb joints. Extinct hominins, including pre-Holocene Homo sapiens, retain the high levels seen in nonhuman primates. Thus, the low trabecular density of the recent modern human skeleton evolved late in our evolutionary history, potentially resulting from increased sedentism and reliance on technological and cultural innovations.

Author(s):  
K. Schwartz ◽  
◽  
M. Sorokin ◽  

The evolution of modern humans began two and a half million years ago as Homo erectus. Several hundred thousand years ago, Neanderthals, Denisovans, and modern men Homo sapiens have been separated from the Homo erectus branch. Nevertheless, Homo sapiens is the only one that has survived to our days. The complex history of Homo is revealed by genetic research and comparison of the modern human genome with genes of Neanderthals and Denisovans. Svante Pääbo, a professor at the Max Planck Institute for Evolutionary Anthropology, made a significant contribution to these studies and decoded the genome of Neanderthals and Denisovans. Comparison of the genome of modern humans with the genes of Neanderthals and Denisovans made it possible to reveal the size of the population, the paths and times of migrations, interactions of various groups of ancient humans and their biological crossing. It was found that in Eurasia, modern man carries traces of Neanderthal genes, whereas in Asia and Oceania – Denisovan genes. According to anthropological research, the survival of Homo sapiens was driven by the cognitive revolution, which took place about seventy thousand years ago and included the development of language, communication and association in large groups.


eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Anjali M Prabhat ◽  
Catherine K Miller ◽  
Thomas Cody Prang ◽  
Jeffrey Spear ◽  
Scott A Williams ◽  
...  

The evolution of bipedalism and reduced reliance on arboreality in hominins resulted in larger lower limb joints relative to the joints of the upper limb. The pattern and timing of this transition, however, remains unresolved. Here, we find the limb joint proportions of Australopithecus afarensis, Homo erectus, and Homo naledi to resemble those of modern humans, whereas those of A. africanus, Australopithecus sediba, Paranthropus robustus, Paranthropus boisei, Homo habilis, and Homo floresiensis are more ape-like. The homology of limb joint proportions in A. afarensis and modern humans can only be explained by a series of evolutionary reversals irrespective of differing phylogenetic hypotheses. Thus, the independent evolution of modern human-like limb joint proportions in A. afarensis is a more parsimonious explanation. Overall, these results support an emerging perspective in hominin paleobiology that A. afarensis was the most terrestrially adapted australopith despite the importance of arboreality throughout much of early hominin evolution.


Author(s):  
Rainer Kühne

I argue that the evidence of the Out-of-Africa hypothesis and the evidence of multiregional evolution of prehistorical humans can be understood if there has been interbreeding between Homo erectus, Homo neanderthalensis, and Homo sapiens at least during the preceding 700,000 years. These interbreedings require descendants who are capable of reproduction and therefore parents who belong to the same species. I suggest that a number of prehistorical humans who are at present regarded as belonging to different species belong in fact to one single species.  


Author(s):  
STEVEN MITHEN

The modern human is a product of six million years of evolution wherein it is assumed that the ancestor of man resembles that of a chimpanzee. This assumption is based on the similarities of the ape-like brain size and post-cranial characteristics of the earliest hominid species to chimpanzees. Whilst it is unclear whether chimpanzees share the same foresight and contemplation of alternatives as with humans, it is nevertheless clear that chimpanzees lack creative imagination — an aspect of modern human imagination that sets humanity apart from its hominid ancestors. Creative imagination pertains to the ability to combine different forms of knowledge and ways of thinking to form creative and novel ideas. This chapter discusses seven critical steps in the evolution of the human imagination. These steps provide a clear picture of the gradual emergence of creative imagination in humans from their primitive origins as Homo sapiens some 200,000 years ago. This chronological evolution of the imaginative mind of humans involves both biological and cultural change that began soon after the divergence of the two lineages that led to modern humans and African apes.


2005 ◽  
Vol 32 ◽  
pp. 221-232 ◽  
Author(s):  
Harald Haarmann

Since the earliest manifestations of symbolic activity in modern humans (Homo sapiens sapiens) in the Upper Palaeolithic, there is evidence for two independent cognitive procedures, for the production of representational images (naturalistic pictures or sculptures) and of abstract signs. The use of signs and symbols is attested for archaic humans (Homo neanderthalensis) and for Homo erectus while art in naturalistic style is an innovation among modern humans. The symbiotic interaction of the two symbolic capacities is illustrated for the visual heritage of Palaeolithic cave paintings in Southwestern Europe, for rock engravings in the Italian Alps (Val Camonica) and for the vivid use of signs and symbols in Southeastern Europe during the Neolithic. Around 5500 BC, sign use in Southeastern Europe reached a sophisticated stage of organization as to produce the earliest writing system of mankind. Since abstractness is the main theme in the visual heritage of the region, this script, not surprisingly, is composed of predominantly abstract signs.


2016 ◽  
Vol 371 (1698) ◽  
pp. 20150247 ◽  
Author(s):  
William L. Jungers ◽  
Mark Grabowski ◽  
Kevin G. Hatala ◽  
Brian G. Richmond

Body size is a fundamental biological property of organisms, and documenting body size variation in hominin evolution is an important goal of palaeoanthropology. Estimating body mass appears deceptively simple but is laden with theoretical and pragmatic assumptions about best predictors and the most appropriate reference samples. Modern human training samples with known masses are arguably the ‘best’ for estimating size in early bipedal hominins such as the australopiths and all members of the genus Homo , but it is not clear if they are the most appropriate priors for reconstructing the size of the earliest putative hominins such as Orrorin and Ardipithecus . The trajectory of body size evolution in the early part of the human career is reviewed here and found to be complex and nonlinear. Australopith body size varies enormously across both space and time. The pre- erectus early Homo fossil record from Africa is poor and dominated by relatively small-bodied individuals, implying that the emergence of the genus Homo is probably not linked to an increase in body size or unprecedented increases in size variation. Body size differences alone cannot explain the observed variation in hominin body shape, especially when examined in the context of small fossil hominins and pygmy modern humans. This article is part of the themed issue ‘Major transitions in human evolution’.


2020 ◽  
Author(s):  
Axel Timmermann

Anatomically Modern Humans are the sole survivor of a group of hominins that inhabited our planet during the last ice age and that included, among others, Homo neanderthalensis, Homo denisova, and Homo erectus. Whether previous hominin extinctions were triggered by external factors, such as abrupt climate change, volcanic eruptions or whether competition and interbreeding played major roles in their demise still remains unresolved. Here I present a spatially resolved numerical hominin dispersal model (HDM) with empirically constrained key parameters that simulates the migration and interaction of Anatomically Modern Humans and Neanderthals in the rapidly varying climatic environment of the last ice age. The model simulations document that rapid temperature and vegetation changes associated with Dansgaard-Oeschger events were not major drivers of global Neanderthal extinction between 50-35 thousand years ago, but played important roles regionally, in particular over northern Europe. According to a series of parameter sensitivity experiments conducted with the HDM, a realistic extinction of the Neanderthal population can only be simulated when Homo sapiens is chosen to be considerably more effective in exploiting scarce glacial food resources as compared to Neanderthals.


2021 ◽  
Author(s):  
Tingting Sun ◽  
Qing Liu ◽  
Meiqi Shang ◽  
Kejian Wang

The origin of human beings is one of the most important questions in science. A combination of numerous archaeological and genomic analyses has led to the widely accepted opinion that modern humans are the descendants of anatomically modern Homo sapiens that originated in Africa about 200 thousand years ago (KYA). In this study, we reanalysed the mitochondrial DNA and Y chromosome DNA of the 1000 Genomes Project, and found many minority-specific single-nucleotide polymorphisms. Using these polymorphisms, we recalculated the time taken for the evolution of modern humans. Analysis of mitochondrial DNA suggested that the most recent common female ancestor lived about 400 KYA and began to leave Africa about 180 KYA. In contrast, analysis of Y chromosome DNA revealed that the most recent common male ancestor lived about 3.67 million years ago (MYA) and began to migrate out of Africa about 2.05 MYA, a time which is consistent with the expansion time of Homo erectus identified by archaeological research. Based on the findings, we proposed a new migration routes and times of modern human, and speculated that anatomically modern Homo sapiens has been extensively interbred with local archaic human population during their dispersal across the globe.


2019 ◽  
Author(s):  
Rainer Walter Kühne

I argue that the evidence of the Out-of-Africa hypothesis and the evidence of multiregional evolution of prehistorical humans can be understood if there has been interbreeding between Homo erectus, Homo neanderthalensis, and Homo sapiens at least during the preceding 700,000 years. These interbreedings require descendants who are capable of reproduction and therefore parents who belong to the same species. I suggest that a number of prehistorical humans who are at present regarded as belonging to different species belong in fact to one single species.


2016 ◽  
Vol 12 (2) ◽  
pp. 365
Author(s):  
Emmanuel Osewe Akubor

Africa has often been referred to as the Home of Civilization. This reference is based on the fact that most of the continent evidences how man has, over time, interacted meaningful with his environment to produce all that he needs to make history. Archaeological remains in Egypt have shed light on this development as far as Africa is concern. Other remains found particularly in central Eastern Africa have been widely recognized such that the area is now widely accepted as the origin of humans and the Hominidae clade (great apes). This is evidenced by the discovery of the earliest hominids and their ancestors, as well as later ones that have been dated to around seven million years ago. These later ones include Sahelanthropus tchadensis, Australopithecus africanus, A. afarensis, Homo erectus, H. habilis, and H. ergaster, with the earliest Homo sapiens (modern human) found in Ethiopia dating far back to circa 200,000 years ago. Now, this rich historical heritage is being threatened by the emergence of some religious movements in Africa. The reason for this is that these religions see the preservation of these relics as idolatry and unacceptable. Data obtained from primary and secondary sources were deployed to carry out the study, and the study was carried out with an analytical and narrative historical method. Findings indicate that while the European world continue to beg for the preservation of these artifacts and in some cases preserve these artifacts and relics in their museums, the emerging groups continue to target these historical artifacts for destruction. This paper argues that this trend is unhealthy for the development of history and preservation of the continent’s heritage. Furthermore, it asserts that once this wanton destruction is not checked, there is a high possibility that in the nearest future, nothing would be left to study in African history.


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