scholarly journals Early Homo , plasticity and the extended evolutionary synthesis

2017 ◽  
Vol 7 (5) ◽  
pp. 20170004 ◽  
Author(s):  
Susan C. Antón ◽  
Christopher W. Kuzawa
Keyword(s):  
Phenotypic Variation ◽  
Fossil Record ◽  
Evolutionary Process ◽  
Homo Erectus ◽  
Evolutionary Synthesis ◽  
Early Pleistocene ◽  
Human Populations ◽  
Extended Evolutionary Synthesis ◽  
Early Homo ◽  
Regional Diversification

The Modern Synthesis led to fundamental advances in understandings of human evolution. For human palaeontology, a science that works from ancestral phenotypes (i.e. the fossil record), particularly important have been perspectives used to help understand the heritable aspects of phenotypes and how fossil individuals might then be aggregated into species, and relationships among these groups understood. This focus, coupled with the fragmentary nature of the fossil record, however, means that individual phenotypic variation is often treated as unimportant ‘noise’, rather than as a source of insight into population adaptation and evolutionary process. The emphasis of the extended evolutionary synthesis on plasticity as a source of phenotypic novelty, and the related question of the role of such variation in long-term evolutionary trends, focuses welcome attention on non-genetic means by which novel phenotypes are generated and in so doing provides alternative approaches to interpreting the fossil record. We review evidence from contemporary human populations regarding some of the aspects of adult phenotypes preserved in the fossil record that might be most responsive to non-genetic drivers, and we consider how these perspectives lead to alternate hypotheses for interpreting the fossil record of early genus Homo. We conclude by arguing that paying closer attention to the causes and consequences of intraspecific phenotypic variation in its own right, as opposed to as noise around a species mean, may inspire a new generation of hypotheses regarding species diversity in the Early Pleistocene and the foundations for dispersal and regional diversification in Homo erectus and its descendants .

Into the Woods Early Homo sapiens and Tropical Forest Colonization

2019 ◽  
Author(s):  
Patrick Roberts
Keyword(s):  
Tropical Forests ◽  
Late Pleistocene ◽  
Homo Sapiens ◽  
Homo Erectus ◽  
Rapid Expansion ◽  
Early Pleistocene ◽  
Human Populations ◽  
Tropical Regions ◽  
Early Homo ◽  
Middle And Late Pleistocene

Popular philosophical associations of tropical forests, and forests in general, with an inherent ancestral state, away from the stresses, pollution, and technosphere of modern life, are nicely summarized by Murakami’s quote above (2002). Given the probable origins of the hominin clade in tropical forests, this quote is also apt from an evolutionary standpoint. Yet, somewhat surprisingly, tropical forests have frequently been considered impenetrable barriers to the global migration of Homo sapiens (Gamble, 1993; Finlayson, 2014). As was the case with the focus on ‘savannastan’ in facilitating the Early Pleistocene expansion of Homo erectus discussed in Chapter 3 (Dennell and Roebroeks, 2005), the movement of H. sapiens into tropical regions such as South Asia, Southeast Asia, and Australia has tended to be linked to Late Pleistocene periods when forests contracted and grasslands expanded (Bird et al., 2005; Boivin et al., 2013). Alternative narratives have focused on the importance of coastal adaptations as providing a rich source of protein and driving cultural and technological complexity, as well as mobility, in human populations during the Middle and Late Pleistocene (Mellars, 2006; Marean, 2016). The evidence of early art and symbolism at coastal cave sites such as Blombos in South Africa (Henshilwood et al., 2002, 2011; Vanhaeren et al., 2013) and Taforalt in North Africa (Bouzouggar et al., 2007) is often used to emphasize the role of marine habitats in the earliest cultural emergence of our species. Indeed, for the last decade, the pursuit of rich marine resources (Mellars, 2005, 2006) has been a popular explanation for the supposed rapidity of the ‘southern dispersal route’, whereby humans left Africa 60 ka, based on genetic information (e.g., Macaulay et al., 2005), to reach the Pleistocene landmass that connected Australia and New Guinea (Sahul) by c. 65 ka (Clarkson et al., 2017). In both of these cases, the coast or expanses of grassland have been seen as homogeneous corridors, facilitating rapid expansion without novel adaptation.

scholarly journals Homo naledi, a new species of the genus Homo from the Dinaledi Chamber, South Africa

eLife ◽  
2015 ◽  
Vol 4 ◽  
Author(s):  
Lee R Berger ◽  
John Hawks ◽  
Darryl J de Ruiter ◽  
Steven E Churchill ◽  
Peter Schmid ◽  
...  
Keyword(s):  
South Africa ◽  
Single Species ◽  
Homo Erectus ◽  
Cranial Morphology ◽  
Human Populations ◽  
Early Homo ◽  
Homo Habilis ◽  
Cave System ◽  
Unknown Species ◽  
Cradle Of Humankind

Homo naledi is a previously-unknown species of extinct hominin discovered within the Dinaledi Chamber of the Rising Star cave system, Cradle of Humankind, South Africa. This species is characterized by body mass and stature similar to small-bodied human populations but a small endocranial volume similar to australopiths. Cranial morphology of H. naledi is unique, but most similar to early Homo species including Homo erectus, Homo habilis or Homo rudolfensis. While primitive, the dentition is generally small and simple in occlusal morphology. H. naledi has humanlike manipulatory adaptations of the hand and wrist. It also exhibits a humanlike foot and lower limb. These humanlike aspects are contrasted in the postcrania with a more primitive or australopith-like trunk, shoulder, pelvis and proximal femur. Representing at least 15 individuals with most skeletal elements repeated multiple times, this is the largest assemblage of a single species of hominins yet discovered in Africa.

scholarly journals Theoretical plurality, the extended evolutionary synthesis, and archaeology

2021 ◽  
Vol 118 (2) ◽  
pp. e2006564118
Author(s):  
Anna Marie Prentiss
Keyword(s):  
Behavioral Ecology ◽  
Cultural Evolution ◽  
Cultural Transmission ◽  
Evolutionary Process ◽  
Evolutionary Synthesis ◽  
Theoretical Frameworks ◽  
Extended Evolutionary Synthesis ◽  
Cognitive Archaeology ◽  
Research Questions ◽  
Cultural Evolutionary

The study of cultural evolution now includes multiple theoretical frameworks. Despite common influence from Darwinian evolutionary theory, there is considerable diversity. Thus, we recognize those most influenced by the tenets of the Modern Synthesis (evolutionary archaeology, cultural transmission theory, and human behavioral ecology) and those most aligned more closely with concepts emerging in the Extended Evolutionary Synthesis (cultural macroevolution and evolutionary cognitive archaeology). There has been substantial debate between adherents of these schools of thought as to their appropriateness and priority for addressing the fundamentals of cultural evolution. I argue that theoretical diversity is necessary to address research questions arising from a complex archaeological record. Concepts associated with the Extended Evolutionary Synthesis may offer unique insights into the cultural evolutionary process.

scholarly journals Assessing elements of an extended evolutionary synthesis for plant domestication and agricultural origin research

2017 ◽  
Vol 114 (25) ◽  
pp. 6429-6437 ◽  
Author(s):  
Dolores R. Piperno
Keyword(s):  
Developmental Plasticity ◽  
Evolutionary Process ◽  
Epigenetic Inheritance ◽  
Evolutionary Synthesis ◽  
Plant Domestication ◽  
Extended Evolutionary Synthesis ◽  
Ecological History ◽  
Environmental Perturbations ◽  
Agricultural Societies ◽  
Wild Progenitors

The development of agricultural societies, one of the most transformative events in human and ecological history, was made possible by plant and animal domestication. Plant domestication began 12,000–10,000 y ago in a number of major world areas, including the New World tropics, Southwest Asia, and China, during a period of profound global environmental perturbations as the Pleistocene epoch ended and transitioned into the Holocene. Domestication is at its heart an evolutionary process, and for many prehistorians evolutionary theory has been foundational in investigating agricultural origins. Similarly, geneticists working largely with modern crops and their living wild progenitors have documented some of the mechanisms that underwrote phenotypic transformations from wild to domesticated species. Ever-improving analytic methods for retrieval of empirical data from archaeological sites, together with advances in genetic, genomic, epigenetic, and experimental research on living crop plants and wild progenitors, suggest that three fields of study currently little applied to plant domestication processes may be necessary to understand these transformations across a range of species important in early prehistoric agriculture. These fields are phenotypic (developmental) plasticity, niche construction theory, and epigenetics with transgenerational epigenetic inheritance. All are central in a controversy about whether an Extended Evolutionary Synthesis is needed to reconceptualize how evolutionary change occurs. An exploration of their present and potential utility in domestication study shows that all three fields have considerable promise in elucidating important issues in plant domestication and in agricultural origin and dispersal research and should be increasingly applied to these issues.

scholarly journals Dmanisi hominin fossils and the problem of the multiple species in the early Homo genus

2015 ◽  
Vol 23 (2) ◽  
pp. 1-21
Author(s):  
Santiago Wolnei Ferreira Guimarães ◽  
Carlos Lorenzo Merino
Keyword(s):  
Coefficient Of Variation ◽  
Homo Erectus ◽  
Early Pleistocene ◽  
Early Homo ◽  
Homo Habilis ◽  
Variation Range ◽  
Multiple Species ◽  
Unique Species

The D4500 (Skull 5), dated 1.8 Mya., is the most complete fossil within the set of five skulls found in Dmanisi, Georgia, as well as any other fossils associated to contexts of occupation of the early Pleistocene. Its discovery has brought forward the debate of the plurality of species, not just at the beginning of the Homo genus, but for much of its evolution.  The Skull 5 fossil presents a mixure of primitive and derivates characters associated to the Homo erectus and Homo habilis sensu lato. Based on the data referring to the five skulls researchers have considered the hypothesis of a single evolving lineage of early Homo as a mode to explain the great variation range of the Dmanisi fossils, similar to the range found in habilines. In other words, it is an explanation that reiterates the existence of only one unique species in the early of the Homo genus: the Homo erectus in a sensu lato. Our work consists of evaluating such supposition through the calculation of the coefficient of variation, which was estimated from the referred set and compared to those from already known species. Results achieved did not support the thinking that one unique species was able to bear all fossils of the early of Homo genus.  

scholarly journals Between Teleophilia and Teleophobia

Biosemiotics ◽  
2021 ◽  
Author(s):  
Eric Schaetzle ◽  
Yogi Hendlin
Keyword(s):  
Theoretical Biology ◽  
Modern Synthesis ◽  
Theory Building ◽  
Evolutionary Synthesis ◽  
Evolutionary Processes ◽  
Extended Evolutionary Synthesis ◽  
New Findings ◽  
Multi Level

AbstractDenis Noble convincingly describes the artifacts of theory building in the Modern Synthesis as having been surpassed by the available evidence, indicating more active and less gene-centric evolutionary processes than previously thought. We diagnosis the failure of theory holders to dutifully update their beliefs according to new findings as a microcosm of the prevailing larger social inability to deal with competing paradigms. For understanding life, Noble suggests that there is no privileged level of semiotic interpretation. Understanding multi-level semiosis along with organism and environment contrapunctally, according to Jakob von Uexküll’s theoretical biology, can contribute to the emerging extended evolutionary synthesis.

scholarly journals Evolutionary biology today and the call for an extended synthesis

2017 ◽  
Vol 7 (5) ◽  
pp. 20160145 ◽  
Author(s):  
Douglas J. Futuyma
Keyword(s):  
Natural Selection ◽  
Evolutionary Theory ◽  
Evolutionary Biology ◽  
Epigenetic Inheritance ◽  
Reaction Norm ◽  
Evolutionary Synthesis ◽  
Historical Background ◽  
Extended Evolutionary Synthesis ◽  
Extended Synthesis ◽  
Proximate Causation

Evolutionary theory has been extended almost continually since the evolutionary synthesis (ES), but except for the much greater importance afforded genetic drift, the principal tenets of the ES have been strongly supported. Adaptations are attributable to the sorting of genetic variation by natural selection, which remains the only known cause of increase in fitness. Mutations are not adaptively directed, but as principal authors of the ES recognized, the material (structural) bases of biochemistry and development affect the variety of phenotypic variations that arise by mutation and recombination. Against this historical background, I analyse major propositions in the movement for an ‘extended evolutionary synthesis’. ‘Niche construction' is a new label for a wide variety of well-known phenomena, many of which have been extensively studied, but (as with every topic in evolutionary biology) some aspects may have been understudied. There is no reason to consider it a neglected ‘process’ of evolution. The proposition that phenotypic plasticity may engender new adaptive phenotypes that are later genetically assimilated or accommodated is theoretically plausible; it may be most likely when the new phenotype is not truly novel, but is instead a slight extension of a reaction norm already shaped by natural selection in similar environments. However, evolution in new environments often compensates for maladaptive plastic phenotypic responses. The union of population genetic theory with mechanistic understanding of developmental processes enables more complete understanding by joining ultimate and proximate causation; but the latter does not replace or invalidate the former. Newly discovered molecular phenomena have been easily accommodated in the past by elaborating orthodox evolutionary theory, and it appears that the same holds today for phenomena such as epigenetic inheritance. In several of these areas, empirical evidence is needed to evaluate enthusiastic speculation. Evolutionary theory will continue to be extended, but there is no sign that it requires emendation.

scholarly journals Dental tissue proportions in fossil orangutans from mainland Asia and Indonesia

2011 ◽  
Vol 1 (1) ◽  
pp. e1 ◽  
Author(s):  
Tanya M. Smith ◽  
Anne-Marie Bacon ◽  
Fabrice Demeter ◽  
Ottmar Kullmer ◽  
Kim Thuy Nguyen ◽  
...  
Keyword(s):  
Fossil Record ◽  
Homo Sapiens ◽  
Homo Erectus ◽  
Dental Tissue ◽  
Developmental Constraints ◽  
Enamel Thickness ◽  
Selective Pressures ◽  
The Past ◽  
Geometric Scaling ◽  
Dental Reduction

Orangutans (Pongo) are the only great ape genus with a substantial Pleistocene and Holocene fossil record, demonstrating a much larger geographic range than extant populations. In addition to having an extensive fossil record, Pongo shows several convergent morphological similarities with Homo, including a trend of dental reduction during the past million years. While studies have documented variation in dental tissue proportions among species of Homo, little is known about variation in enamel thickness within fossil orangutans. Here we assess dental tissue proportions, including conventional enamel thickness indices, in a large sample of fossil orangutan postcanine teeth from mainland Asia and Indonesia. We find few differences between regions, except for significantly lower average enamel thickness (AET) values in Indonesian mandibular first molars. Differences between fossil and extant orangutans are more marked, with fossil Pongo showing higher AET in most postcanine teeth. These differences are significant for maxillary and mandibular first molars. Fossil orangutans show higher AET than extant Pongo due to greater enamel cap areas, which exceed increases in enamel-dentine junction length (due to geometric scaling of areas and lengths for the AET index calculation). We also find greater dentine areas in fossil orangutans, but relative enamel thickness indices do not differ between fossil and extant taxa. When changes in dental tissue proportions between fossil and extant orangutans are compared with fossil and recent Homo sapiens, Pongo appears to show isometric reduction in enamel and dentine, while crown reduction in H. sapiens appears to be due to preferential loss of dentine. Disparate selective pressures or developmental constraints may underlie these patterns. Finally, the finding of moderately thick molar enamel in fossil orangutans may represent an additional convergent dental similarity with Homo erectus, complicating attempts to distinguish these taxa in mixed Asian faunas. 

Hybrid crinoids in the fossil record (Early Mississippian, Phylum Echinodermata)

Paleobiology ◽  
1994 ◽  
Vol 20 (3) ◽  
pp. 362-367 ◽  
Author(s):  
William I. Ausich ◽  
David L. Meyer
Keyword(s):  
Fossil Record ◽  
Evolutionary Process ◽  
Parent Species ◽  
Probable Explanation ◽  
South Central ◽  
Most Probable Explanation ◽  
The Impact

Potential hybrid fossil crinoids, Eretmocrinus magnificus x Eretmocrinus praegravis, are identified from the Lower Mississippian Fort Payne Formation of south-central Kentucky. These are the first fossil hybrid crinoids identified, and one of very few examples of hybrids recognized in the fossil record. Eretmocrinus magnificus x E. praegravis specimens have shapes and calyx plate sculpturing that are morphologically intermediate between well-defined, distinct parent species. Suspected hybrids occur at localities where parent species co-occur and where the parent species are the most abundant; the hybrids occur at what may have been the distributional margins of the parent species; and the mixture of characters on suspected hybrids seems to be morphogenetically partitioned. Parent species are derived from separate lineages within Eretmocrinus, and hybridization is the most probable explanation for these morphologically intermediate specimens. This example highlights the need to consider hybridization as a potential interpretation of intermediate morphologies among fossils and raises questions concerning the impact of hybridization for our interpretation of the fossil record and the role of hybridization in the evolutionary process.

Sign in / Sign up

Export Citation Format

Share Document