Sex and Cohabitation Among Early Humans: Anthropological and Genetic Evidence for Interbreeding Among Early Humans

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Sex and Cohabitation Among Early Humans: Anthropological and Genetic Evidence for Interbreeding Among Early Humans
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Contents
About the authors
Chapter 1: Origin and diversity of hominins
Origin of the apes
The earliest apes
Apes out of Africa
Repatriated apes
The common ancestors
The genesis of hominins
Was Sahelanthropus a hominin?
Was Orrorin tugenensis bipedal?
Were ardipithecines arboreal, terrestrial, or both?
Reassessment of the Paleoenvironment of early hominins
How diversified were hominins-Is the tree linear or bushy?
The single species hypothesis
Hominin diversity in time and space
Temporal overlap
Cases of coexistence among hominins
Ardipithecus ramidus/Australopithecus anamensis/Australopithecus afarensis
Lucy and company
Two's company, four's a crowd
Homo naledi and other recent hominins in South Africa
Dmanisi: Extreme anatomical differences within a species or coexistence among different populations?
One-night stands or prolonged coexistence?
Transitional industries and technology transfer
Neanderthals: Acculturated or the acculturators?
References
Chapter 2: The species concept and the reality of introgression
Evolution and the species concept
What constitutes a species
Historical definitions of species
Species classification and the variety of species concepts
Importance of species identification
Speciation
Geographical modes of speciation: Allopatric, peripatric, parapatric, and sympatric
Allopatric speciation and peripatric speciation
Parapatric speciation
Sympatric speciation
Prezygotic mechanisms of reproductive isolation
Sexual selection
Ecological isolation
Behavioral isolation
Gametic isolation
Hybrid speciation
Neanderthal human introgression and the concept of speciation
Conclusions
References
Chapter 3: The evolution of sex
Sex evolves when selection pressures change over time and space
Gender determination
Hermaphroditism
Congenital adrenal hyperplasia
Androgen insensitivity syndrome
Turner syndrome
XXX females
Klinefelter syndrome
XYY males (Jacobs syndrome)
Homosexuality
Menstruation and fertility
Mating
Sexual strategies
Sexual dimorphism
Conclusion
References
Chapter 4: Archeological tools used to study hominin evolution
An integrative approach
Archeology
Origins and evolution of archeology
Antiquarianism
The age of enlightenment
Nationalistic archeology
The start of excavations
Development of methodological archeology
Contemporary archeology
Survey
Preliminary search
Walking survey
Remote reconnaissance
Aerial and satellite reconnaissance
Excavation
Recording the events
Postexcavation analysis
Dating and ancient DNA sequencing
Relative dating
Absolute dating
Isotope ratios
14C/12C
40K/40Ar
Uranium series
87Rb/87Sr
Radiation exposure techniques
Fission-track
Thermoluminescence
Electron spin resonance
Geomagnetic polarity
Amino acid racemization
Other dating methodologies
Composition, texture, and style of artifacts
Pottery and ceramic
Lithics
Ecofacts
Statistical analyses
Provenance analysis
References
Chapter 5: Hominin fossils: Anatomical trends
The new physical anthropology
Technical advances
Misinterpretation with a twist of imagination: The first hominin fossils found
The Red Lady
Engis 2
Gibraltar 1
Feldhofer 1 or Neanderthal 1
Trends in hominin evolution
What triggered the split between the apes and hominins?
Hallmarks of hominin evolution
Mosaicism
Independence and interconnection of traits
Continuity of traits
Bipedal locomotion
Evolutionary forces that may have influenced upright posture and bipedalism
Anatomical traits impacted by bipedalism
Bipedalism as a function of hominin species and evolutionary time
Encephalization
Encephalization as a function of evolutionary time
Encephalization in Africa versus Eurasia
Brain reorganization during hominin evolution
Recent anatomical changes in the AMH brain
Independent encephalization processes in Neanderthals and AMHs
What drove hominin encephalization?
References
Chapter 6: Molecular biology tools used to study hominin evolution
From genetics to molecular biology
Genesis of molecular biology
Key discoveries in molecular biology
Restriction enzymes
DNA cloning
DNA sequencing
Polymerase chain reaction (PCR)
Microchip technology/DNA microarrays
Assessing hominin evolution
Types of DNA
Allelic frequencies
Types of genetic variation
Single nucleotide polymorphisms (SNPs)
Short tandem repeats (STRs)
Indels (insertion/deletions)
Ancient retroviral insertions
Analytical methods
Tools for analyzing population structure and phylogenetic relationships
Internal population genetics parameters
Interspecific population genetics parameters
Model-based versus distance-based phylogenies
PCA
MDS
Hierarchical clusters analysis (HCA)
Network analysis
Structure analysis
AMOVA (analysis of molecular variance)
Linear versus haplotype-based approaches
Identity-by-descent (IBD) tracks
The globetrotter algorithms to detect admixture
Data visualization tools
Heat maps
Contour maps
References
Chapter 7: Continuity of traits among hominins
Continuity is fundamental to life and evolution
Continuity as a function of time
Ancestral and derived traits
Continuity and the multiregional model of hominin evolution
The revised multiregional model
The assimilation or partial replacement model
What does the evidence say?
Indonesia-Australia
East Asia
Hualongdong
Dali
Xuchang
Europe
The lineages of Neanderthals and sapiens
Early enclaves of sapiens in Southwest Asia and Europe
Apidima
Zuttiyeh
Misliya
Skhul and Qafzeh
Were Neanderthals and sapiens at the fringe of reproductive isolation?
Regional continuity in Europe
Does DNA show regional continuity?
mtDNA
Genetic expectations of the OOA model
Inconsistencies involving the OOA model
Some concluding remarks
References
Chapter 8: An African-wide origin of Homo sapiens
Issues to consider when thinking of hominin evolution
Single region of origin models
A shift in paradigm
Genesis of the Pan-African theory of hominin evolution
Fossil evidence
Jebel Irhoud
Florisbad
Omo
Herto
Phylogenetic modeling reconstruction-A virtual human common ancestor
Technological homogeneity within Africa
Genetic diversity and the age of genes
Genomic inference from linkage disequilibrium
Conclusions
References
Chapter 9: The first out of Africa migrants
The first hominin migrants out of Africa
Bipedal movement
The evolution of the human brain
Tool technology and human behavior
The rise of the genus Homo
Origin of modern humans
Routes out of Africa
The Horn of Africa
The Levant
Genetic data
Migration of Homo sapiens
Migrational motivation
Climate changes
Environmental changes
Conclusion
References
Chapter 10: Neanderthal origin and fossil record
Origins of Neanderthals from early human species
Climatic conditions before and after the introduction of modern humans to Europe
Neanderthal fossil discovery
Use of stone tools
Growth and development of Neanderthals
Dental characteristics
Cranial anatomy
Body mass and development
References
Chapter 11: Fossil and genetic evidence for Neanderthal introgression
The early evolution of humans and Neanderthals
Synopsis of Homo sapiens emergence from Africa
Synopsis of Neanderthal evolutionary history and appearance in Europe
Evidence for introgression between Neanderthals and AMHs
Linkage and linkage disequilibrium
Introgression versus ancient population structure
Nature of Neanderthal introgression
Selection and adaptive introgression
Drift
Balancing selection
How humans both dominated and interacted with other species
Stone age people avoided incest
Introgression inside Africa
Were there early interactions between Neanderthals and anatomically modern humans?
Conclusion
References
Chapter 12: Neanderthal habitat, culture, language, and intellect
Human origins and the development of culture
Neanderthal behavior
Neanderthal tools
Neanderthal language
Neanderthal diet
Neanderthal symbolism and cognition
Neanderthal and humans interacting
Genetic data
Conclusion
References
Chapter 13: To what extent did Neanderthals and modern humans interact?
Historical precedence
Self or different?
A violent past
Violence among Paleolithic sapiens
Cioclovina
Sunghir 1
Skhul IX
Violence among Neanderthals
Cranium 17
Shanidar 3
St Césaire 1
El Sidrón
AMH violence directed at Neanderthals?
Les Rois
Increase in interpersonal violence since the Middle Paleolithic
Hard-wired to violence
Violence was not ubiquitous
Other signs of intimacy
An effort to explain Neanderthals extinction
Competition
Bigger eyes and visual brain centers
Inbreeding
Technological advances and improved hunting techniques
Assimilation
References
Chapter 14: The extinction of Neanderthals
What happened?
Evidence for Neanderthal and anatomically modern human interactions
Climate change and geological events
AMH competition
Genetic disparities and Neanderthal extinction
Disease transmission
Small populations and inbreeding depression
Conclusion
References
Chapter 15: The Denisovans
In the beginning
The Denisovans
Ancient genomic DNA and mtDNA
Interbreeding
What did the Denisovans look like?
Acquisition of human characteristics
Extinction
Conclusion
References
Chapter 16: Interwoven evolution of Homo erectus, Homo floresiensis, and Homo sapiens
Continental East Asia
Island Southeast Asia
Kalinga, Luzon
Callao Cave, Luzon
Indonesia-Australia
Java
Sulawesi
Flores
Liang Bua (Homo floresiensis)
Mata Menge
Wolo Sege
One million years of technological continuity in Flores
How Homo erectus reached the island of Flores
How is ancient admixture/introgression determined?
Conclusions
References
Index
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