1
|
Pestana C, de Sousa AA, Todorov OS, Beaudet A, Benoit J. Evolutionary history of hominin brain size and phylogenetic comparative methods. PROGRESS IN BRAIN RESEARCH 2023; 275:217-232. [PMID: 36841569 DOI: 10.1016/bs.pbr.2022.12.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
An absolutely and relatively large brain has traditionally been viewed as a distinctive characteristic of the Homo genus, with anatomically modern humans presented at the apex of a long line of progressive increases in encephalization. Many studies continue to focus attention on increasing brain size in the Homo genus, while excluding measures of absolute and relative brain size of more geologically recent, smaller brained, hominins such as Homo floresiensis, and Homo naledi and smaller brained Homo erectus specimens. This review discusses the benefits of using phylogenetic comparative methods to trace the diverse changes in hominin brain evolution and the drawbacks of not doing so.
Collapse
Affiliation(s)
- Christopher Pestana
- Evolutionary Studies Institute, School of Geosciences, University of the Witwatersrand, Johannesburg, South Africa
| | | | - Orlin S Todorov
- School of Natural Sciences, Macquarie University, Sydney, NSW, Australia
| | - Amélie Beaudet
- Department of Archaeology, University of Cambridge, Cambridge, United Kingdom; School of Geography, Archaeology and Environmental Studies, University of the Witwatersrand, Johannesburg, South Africa; Institut Català de Paleontologia Miquel Crusafont, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Julien Benoit
- Evolutionary Studies Institute, School of Geosciences, University of the Witwatersrand, Johannesburg, South Africa
| |
Collapse
|
2
|
Rigby Dames BA, Kilili H, Charvet CJ, Díaz-Barba K, Proulx MJ, de Sousa AA, Urrutia AO. Evolutionary and genomic perspectives of brain aging and neurodegenerative diseases. PROGRESS IN BRAIN RESEARCH 2023; 275:165-215. [PMID: 36841568 PMCID: PMC11191546 DOI: 10.1016/bs.pbr.2022.10.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
This chapter utilizes genomic concepts and evolutionary perspectives to further understand the possible links between typical brain aging and neurodegenerative diseases, focusing on the two most prevalent of these: Alzheimer's disease and Parkinson's disease. Aging is the major risk factor for these neurodegenerative diseases. Researching the evolutionary and molecular underpinnings of aging helps to reveal elements of the typical aging process that leave individuals more vulnerable to neurodegenerative pathologies. Very little is known about the prevalence and susceptibility of neurodegenerative diseases in nonhuman species, as only a few individuals have been observed with these neuropathologies. However, several studies have investigated the evolution of lifespan, which is closely connected with brain size in mammals, and insights can be drawn from these to enrich our understanding of neurodegeneration. This chapter explores the relationship between the typical aging process and the events in neurodegeneration. First, we examined how age-related processes can increase susceptibility to neurodegenerative diseases. Second, we assessed to what extent neurodegeneration is an accelerated form of aging. We found that while at the phenotypic level both neurodegenerative diseases and the typical aging process share some characteristics, at the molecular level they show some distinctions in their profiles, such as variation in genes and gene expression. Furthermore, neurodegeneration of the brain is associated with an earlier onset of cellular, molecular, and structural age-related changes. In conclusion, a more integrative view of the aging process, both from a molecular and an evolutionary perspective, may increase our understanding of neurodegenerative diseases.
Collapse
Affiliation(s)
- Brier A Rigby Dames
- Department of Computer Science, University of Bath, Bath, United Kingdom; Department of Psychology, University of Bath, Bath, United Kingdom.
| | - Huseyin Kilili
- Milner Centre for Evolution, Department of Biology and Biochemistry, University of Bath, Bath, United Kingdom
| | - Christine J Charvet
- Department of Anatomy, Physiology and Pharmacology, College of Veterinary Medicine, Auburn University, Auburn, AL, United States
| | - Karina Díaz-Barba
- Licenciatura en Ciencias Genómicas, UNAM, CP62210, Cuernavaca, México; Instituto de Ecología, UNAM, Ciudad Universitaria, CP04510, Ciudad de México, México
| | - Michael J Proulx
- Department of Psychology, University of Bath, Bath, United Kingdom
| | | | - Araxi O Urrutia
- Milner Centre for Evolution, Department of Biology and Biochemistry, University of Bath, Bath, United Kingdom; Licenciatura en Ciencias Genómicas, UNAM, CP62210, Cuernavaca, México; Instituto de Ecología, UNAM, Ciudad Universitaria, CP04510, Ciudad de México, México.
| |
Collapse
|
3
|
DeCasien AR, Barton RA, Higham JP. Understanding the human brain: insights from comparative biology. Trends Cogn Sci 2022; 26:432-445. [DOI: 10.1016/j.tics.2022.02.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 01/27/2022] [Accepted: 02/08/2022] [Indexed: 02/08/2023]
|
4
|
Interpopulational variation in human brain size: implications for hominin cognitive phylogeny. ANTHROPOLOGICAL REVIEW 2022. [DOI: 10.2478/anre-2021-0029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Abstract
Throughout the hominin lineage brain size is believed to have increased threefold – increase which, it is argued by some researchers, results in the enhanced brain power that distinguishes humans from any other living being. However, as we demonstrate in this article this supposed increase is the result of comparing the species mean of contemporary humans with other great apes and fossil hominins. This method obscures both interpopulational variation among modern humans, and the fact that the putative increases in the mean are the result of an increase in the upper limit in some populations, which has the result of obscuring the relative stasis in the lower limit over the last 600k years. For example, populations such as Aboriginal Australians have a range that is more different from Danes than it is from that of Asian H. erectus over the last 600ka. Yet Aboriginal Australians, whose unique anatomy seems to be related to the climatic conditions of Australia, possess all of the socio-cognitive traits characteristic of all other modern-day populations – yet they seemed not to have undergone increase in brain size to the degree that many other populations have. In this instance brain size seems to be unrelated to cognition. In this article we present a statistical analysis of interpopulational variation in contemporary humans and why such an analysis is crucial for our understanding of hominin cognitive, social and technological evolution. We also suggest how such variation may add to our understanding of hominin ontogeny or life history. Additionally, we develop a model based on humanity’s unique form of embodied social cognition that results from our upright bipedal posture and hand morphology. This model is then used to explain the results of our statistical analysis and the possible factors underpinning the human emergence.
Collapse
|
5
|
Divergence-time estimates for hominins provide insight into encephalization and body mass trends in human evolution. Nat Ecol Evol 2021; 5:808-819. [PMID: 33795855 DOI: 10.1038/s41559-021-01431-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Accepted: 02/25/2021] [Indexed: 12/18/2022]
Abstract
Quantifying speciation times during human evolution is fundamental as it provides a timescale to test for the correlation between key evolutionary transitions and extrinsic factors such as climatic or environmental change. Here, we applied a total evidence dating approach to a hominin phylogeny to estimate divergence times under different topological hypotheses. The time-scaled phylogenies were subsequently used to perform ancestral state reconstructions of body mass and phylogenetic encephalization quotient (PEQ). Our divergence-time estimates are consistent with other recent studies that analysed extant species. We show that the origin of the genus Homo probably occurred between 4.30 and 2.56 million years ago. The ancestral state reconstructions show a general trend towards a smaller body mass before the emergence of Homo, followed by a trend towards a greater body mass. PEQ estimations display a general trend of gradual but accelerating encephalization evolution. The obtained results provide a rigorous temporal framework for human evolution.
Collapse
|
6
|
Melchionna M, Mondanaro A, Serio C, Castiglione S, Di Febbraro M, Rook L, Diniz-Filho JAF, Manzi G, Profico A, Sansalone G, Raia P. Macroevolutionary trends of brain mass in Primates. Biol J Linn Soc Lond 2019. [DOI: 10.1093/biolinnean/blz161] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Abstract
A distinctive trait in primate evolution is the expansion in brain mass. The potential drivers of this trend and how and whether encephalization influenced diversification dynamics in this group are hotly debated. We assembled a phylogeny accounting for 317 primate species, including both extant and extinct taxa, to identify macroevolutionary trends in brain mass evolution. Our findings show that Primates as a whole follow a macroevolutionary trend for an increase in body mass, relative brain mass and speciation rate over time. Although the trend for increased encephalization (brain mass) applies to all Primates, hominins stand out for their distinctly higher rates. Within hominins, this unique trend applies linearly over time and starts with Australopithecus africanus. The increases in both speciation rate and encephalization begin in the Oligocene, suggesting the two variables are causally associated. The substitution of early, stem Primates belonging to plesiadapiforms with crown Primates seems to be responsible for these macroevolutionary trends. However, our findings also suggest that cognitive capacities favoured speciation in hominins.
Collapse
Affiliation(s)
- M Melchionna
- Dipartimento di Scienze della Terra, dell’Ambiente e delle Risorse, Università degli Studi di Napoli Federico II, Italy
| | - A Mondanaro
- Dipartimento di Scienze della Terra, dell’Ambiente e delle Risorse, Università degli Studi di Napoli Federico II, Italy
- Department of Earth Sciences, University of Florence, Italy
| | - C Serio
- Dipartimento di Scienze della Terra, dell’Ambiente e delle Risorse, Università degli Studi di Napoli Federico II, Italy
| | - S Castiglione
- Dipartimento di Scienze della Terra, dell’Ambiente e delle Risorse, Università degli Studi di Napoli Federico II, Italy
| | - M Di Febbraro
- Dipartimento di Bioscienze e Territorio, University of Molise, C. da Fonte Lappone, 15, 86090 Pesche, IS, Italy
| | - L Rook
- Department of Earth Sciences, University of Florence, Italy
| | - J A F Diniz-Filho
- Departamento de Ecologia, ICB, Universidade Federal de Goiás, Goiânia, GO, Brazil
| | - G Manzi
- Department of Environmental Biology, Sapienza University of Rome, Italy
| | - A Profico
- Department of Environmental Biology, Sapienza University of Rome, Italy
| | - G Sansalone
- Department of Environmental and Rural Sciences, FEARlab, University of New England, Armidale, 2351, NSW, Australia
| | - P Raia
- Dipartimento di Scienze della Terra, dell’Ambiente e delle Risorse, Università degli Studi di Napoli Federico II, Italy
| |
Collapse
|
7
|
Abstract
The dramatic evolutionary expansion of the neocortex, together with a proliferation of specialized cortical areas, is believed to underlie the emergence of human cognitive abilities. In a broader phylogenetic context, however, neocortex evolution in mammals, including humans, is remarkably conservative, characterized largely by size variations on a shared six-layered neuronal architecture. By contrast, the telencephalon in non-mammalian vertebrates, including reptiles, amphibians, bony and cartilaginous fishes, and cyclostomes, features a great variety of very different tissue structures. Our understanding of the evolutionary relationships of these telencephalic structures, especially those of basally branching vertebrates and invertebrate chordates, remains fragmentary and is impeded by conceptual obstacles. To make sense of highly divergent anatomies requires a hierarchical view of biological organization, one that permits the recognition of homologies at multiple levels beyond neuroanatomical structure. Here we review the origin and diversification of the telencephalon with a focus on key evolutionary innovations shaping the neocortex at multiple levels of organization.
Collapse
Affiliation(s)
- Steven D Briscoe
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany.
| | - Clifton W Ragsdale
- Department of Neurobiology, University of Chicago, Chicago, IL 60637, USA; Department of Organismal Biology and Anatomy, University of Chicago, Chicago, IL 60637, USA
| |
Collapse
|