Computational challenges of evolving the language-ready brain

2018 ◽  
Vol 19 (1-2) ◽  
pp. 7-21 ◽  
Author(s):  
Michael A. Arbib
Keyword(s):  
Computational Modeling ◽  
Common Ancestor ◽  
Homo Sapiens ◽  
Mirror System ◽  
Last Common Ancestor ◽  
New Challenges ◽  
The Brain

Abstract Computational modeling of the macaque brain grounds hypotheses on the brain of LCA-m (the last common ancestor of monkey and human). Elaborations thereof provide a brain model for LCA-c (c for chimpanzee). The Mirror System Hypothesis charts further steps via imitation and pantomime to protosign and protolanguage on the path to a "language-ready brain" in Homo sapiens, with the path to speech being indirect. The material poses new challenges for both experimentation and modeling.

Inductive patterning of the embryonic brain in Drosophila

Development ◽  
2002 ◽  
Vol 129 (9) ◽  
pp. 2121-2128
Author(s):  
Damon T. Page
Keyword(s):  
Brain Development ◽  
Common Ancestor ◽  
Last Common Ancestor ◽  
Embryonic Brain ◽  
Germ Layers ◽  
Brain Anomaly ◽  
Prechordal Plate ◽  
Foregut Endoderm ◽  
The Brain ◽  
Brain Patterning

In vertebrates (deuterostomes), brain patterning depends on signals from adjacent tissues. For example, holoprosencephaly, the most common brain anomaly in humans, results from defects in signaling between the embryonic prechordal plate (consisting of the dorsal foregut endoderm and mesoderm) and the brain. I have examined whether a similar mechanism of brain development occurs in the protostome Drosophila, and find that the foregut and mesoderm act to pattern the fly embryonic brain. When the foregut and mesoderm of Drosophila are ablated, brain patterning is disrupted. The loss of Hedgehog expressed in the foregut appears to mediate this effect, as it does in vertebrates. One mechanism whereby these defects occur is a disruption of normal apoptosis in the brain. These data argue that the last common ancestor of protostomes and deuterostomes had a prototype of the brains present in modern animals, and also suggest that the foregut and mesoderm contributed to the patterning of this ‘proto-brain’. They also argue that the foreguts of protostomes and deuterostomes, which have traditionally been assigned to different germ layers, are actually homologous.

scholarly journals Selection for Decreased BRCA2 Functional Activity in Homo sapiens After Divergence from the Chimpanzee-Human Last Common Ancestor

2020 ◽  
Author(s):  
Jinlong Huang ◽  
Yi Zhong ◽  
Alvin P. Makohon-Moore ◽  
Travis White ◽  
Maria Jasin ◽  
...  
Keyword(s):  
Human Evolution ◽  
Functional Activity ◽  
Protein Function ◽  
Common Ancestor ◽  
Homo Sapiens ◽  
Last Common Ancestor ◽  
Nucleotide Polymorphisms ◽  
Cancer Genes ◽  
Dna Double Strand Breaks ◽  
Bioinformatics Analyses

AbstractHumans have an increased incidence of epithelial neoplasia compared to non-human primates. We performed a comparative analysis of 21 non-human primate genomes and 54 ancient human genomes to identify variations in known cancer genes that may explain this difference. We identified 299 human-specific fixed non-silent single nucleotide polymorphisms. Bioinformatics analyses for functional consequences identified a number of variants predicted to have altered protein function, one of which was located at the most evolutionarily conserved domain of human BRCA2. This variant, in which a polar threonine residue replaces a hydrophobic methionine residue to codon 2662 within the DSS1 binding domain, decreases the interactions of BRCA2 with other proteins, specifically the binding of BRCA2 and RAD51, as well as the repairing ability of cells for DNA double-strand breaks. We conclude that a 20% reduction in BRCA2 DNA repair ability was positively selected for in the course of human evolution.One Sentence SummaryReduction of BRCA2 functional activity has been selected for during human evolution since the chimpanzee-human last common ancestor.

scholarly journals The comparative neuroprimatology 2018 (CNP-2018) road map for research on How the Brain Got Language

2018 ◽  
Vol 19 (1-2) ◽  
pp. 370-387 ◽  
Author(s):  
Michael A. Arbib ◽  
Francisco Aboitiz ◽  
Judith M. Burkart ◽  
Michael Corballis ◽  
Gino Coudé ◽  
...  
Keyword(s):  
Comparative Study ◽  
Cultural Evolution ◽  
Common Ancestor ◽  
Great Apes ◽  
Last Common Ancestor ◽  
Road Map ◽  
The Rich ◽  
The Comparative Study ◽  
Brain Behavior ◽  
The Brain

Abstract We present a new road map for research on “How the Brain Got Language” that adopts an EvoDevoSocio perspective and highlights comparative neuroprimatology – the comparative study of brain, behavior and communication in extant monkeys and great apes – as providing a key grounding for hypotheses on the last common ancestor of humans and monkeys (LCA-m) and chimpanzees (LCA-c) and the processes which guided the evolution LCA-m → LCA-c → protohumans → H. sapiens. Such research constrains and is constrained by analysis of the subsequent, primarily cultural, evolution of H. sapiens which yielded cultures involving the rich use of language.

Interweaving protosign and protospeech

2005 ◽  
Vol 6 (2) ◽  
pp. 145-171 ◽  
Author(s):  
Michael A. Arbib
Keyword(s):  
Cultural Evolution ◽  
Common Ancestor ◽  
Homo Sapiens ◽  
Mirror System ◽  
The Common ◽  
Primate Vocalizations

We distinguish “language readiness” (biological) from “having language” (cultural) and outline a hypothesis for the evolution of the language-ready brain and language involving seven stages: S1: grasping; S2: a mirror system for grasping; S3: a simple imitation system for grasping, shared with the common ancestor of human and chimpanzee; S4: a complex imitation system for grasping; S5: protosign, breaking through the fixed repertoire of primate vocalizations to yield an open repertoire for communication; S6: protospeech, the open-ended production and perception of sequences of vocal gestures, without these sequences constituting a full language; and S7: a process of cultural evolution in Homo sapiens yielding full human languages. The present paper will examine the subhypothesis that protosign (S5) formed a scaffolding for protospeech (S6), but that the two interacted with each other in supporting the evolution of brain and body that made Homo sapiens “language-ready”.

Archaeology and the evolutionary neuroscience of language

2018 ◽  
Vol 19 (1-2) ◽  
pp. 256-271 ◽  
Author(s):  
Dietrich Stout
Keyword(s):  
Action Recognition ◽  
Evolutionary Theory ◽  
Common Ancestor ◽  
Language Evolution ◽  
Mirror System ◽  
Last Common Ancestor ◽  
Complex Action ◽  
Language Origins ◽  
Current Contribution ◽  
Evolutionary Neuroscience

Abstract Comparative approaches to language evolution are essential but cannot by themselves resolve the timing and context of evolutionary events since the last common ancestor with chimpanzees. Archaeology can help to fill this gap, but only if properly integrated with evolutionary theory and the ethnographic, ethological, and experimental analogies required to reconstruct the broader social, behavioral, and neurocognitive implications of ancient artifacts. The current contribution elaborates a technological pedagogy hypothesis of language origins by developing the concept of an evolving human technological niche and applying it to investigate two key transitions posited by Arbib’s Mirror System Hypothesis: (1) from complex action recognition and imitation to proto-language, and (2) from proto-language to language.

The Neurology of Religion

2018 ◽  
Author(s):  
Alexandra Maryanski ◽  
Jonathan H. Turner
Keyword(s):  
Common Ancestor ◽  
Homo Sapiens ◽  
Cladistic Analysis ◽  
Homo Erectus ◽  
Religious Organization ◽  
Last Common Ancestor ◽  
Comparative Neuroanatomy ◽  
Religious Behaviors ◽  
Early Humans ◽  
Human Brains

The human propensity for religious behavior and, eventually, religious organization is the by-product of natural selection working on the neuroanatomy of low-sociality and non-group-forming hominins to become more social and group oriented as a necessary strategy for survival on the African savanna. Using cladistic analysis to determine the behavioral and organizational propensities of the last common ancestor to present-day great apes and humans’ hominin ancestors, while at the same time engaging in comparative neuroanatomy of extant great-ape and human brains, the neurological basis of religion is isolated. Religion emerged under early selection pressures to make hominins more social and able to form stable groups. From the combination of dramatically increased emotionality and cognitive functioning, the transition from Homo erectus to Homo sapiens approximately 300,000 year ago created the neurological platform for religious behaviors among early humans.

scholarly journals Palaeoneurology and the Emergence of Language

2020 ◽  
Author(s):  
A. Mounier ◽  
C. Noûs ◽  
A. Balzeau
Keyword(s):  
Basic Property ◽  
Common Ancestor ◽  
Homo Sapiens ◽  
Brain Morphology ◽  
Last Common Ancestor ◽  
Phenotypic Data ◽  
Modern Language ◽  
Origin Of Language ◽  
Additional Support ◽  
Main Ideas

The origin of language has been much debated over the years. Recent research has centred the controversies on two main ideas. Language, as defined by the Basic Property formulated by Chomsky, is a characteristic unique to Homo sapiens that developed in our species in the past 300,000 years. Other scientists argue that the Basic Property is a derived characteristic shared with other hominin species, such as H. neanderthalensis and the last common ancestor of both modern humans and Neandertals, which evolved over a long period of time, perhaps as long as two million years. Palaeoneurology, which studies the phenotype of the brain in past populations, may have left this complex topic aside because of the difficulty of deducing brain morphology from endocasts (imprints of the neurocranium) and inferring function from brain morphology. In this article, we review the various hypotheses on the evolution of language, highlighting the potential of palaeoneurology to help understand this complex aspect of human evolution, and provide an updated interpretation of previously published endocranial phenotypic data from fossil populations. This brings additional support to a long chronology framework for the origin of language in the hominin lineage: the basic property for modern language may have been in place from the last common ancestor of H. sapiens and H. neanderthalensis.

scholarly journals Ambulacrarian insulin-related peptides and their putative receptors suggest how insulin and similar peptides may have evolved from Insulin-like Growth Factor

2021 ◽  
Author(s):  
Jan Adrianus Veenstra
Keyword(s):  
Receptor Tyrosine Kinase ◽  
Common Ancestor ◽  
Neuroendocrine Cells ◽  
Last Common Ancestor ◽  
Gene Duplications ◽  
Hormonal Signal ◽  
Intracellular Response ◽  
G Protein Coupled ◽  
The Brain ◽  
Insulin Like Growth Factors

Background: Insulin is evolutionarily related to the insulin-like growth factors (IGFs) and like the latter stimulates a receptor tyrosine kinase (RTK) that transfers the extracellular hormonal signal into an intracellular response. Other hormones related to insulin, such as relaxin, do not use an RTK, but a G-protein coupled receptor (GPCR). This is unusual since evolutionarily related hormones typically either use the same or paralogous receptors. In arthropods three different IGF-related peptides likely evolved from a gene triplication, as in several species genes coding these three peptides are located next to one another on the same chromosomal fragment. Of these three hormones one, an IGF-like hormone, acts through an RTK, while the other two use a GPCR. This suggests that the ancestral IGF-like peptide may have used both types of receptors. These arthropod insulin-like peptides have homologs in vertebrates, which suggests that the initial gene triplication was perhaps already present in the last common ancestor of deuterostomes and protostomes. It would be interesting to know whether this is indeed so and to establish how insulin and other insulin-like peptides might be related to this trio of IGF-related hormones. Methodology: Genes coding insulin and related peptides as well as their putative receptors were identified in genomes and transcriptomes from echinoderms and hemichordates. Results: A similar triplet of genes coding insulin-like peptides is also found in some hemichordates and echinoderms. Two of the three ambulacrarian peptides are orthologs of arthropod IGF and Drosophila insulin-like peptide 7 (dilp7), while the third one looks like an ortholog of the arthropod peptide gonadulin. In echinoderms two novel insulin-like peptides emerged, gonad stimulating substance (GSS) and multinsulin, likely from gene duplications of the IGF and dilp7-like genes respectively. However, no novel receptors for insulin-like peptides evolved. If IGF were to act through both a GPCR and an RTK it would suggest that GSS acts on only one of the two receptors, possibly the RTK. The evolution of GSS from IGF may represent a pattern, where IGF gene duplications lead to novel genes coding shorter peptides that have lost their ability to activate a GPCR. It is likely this is how insulin and the insect neuroendocrine insulin-like peptides evolved independently from IGF. Conclusion: The local gene triplication previously described from arthropods that yielded three genes coding IGF-related peptides was already present in the last common ancestor of protostomes and deuterostomes. It seems plausible that insulin and other insulin-like peptides, such as those produced by neuroendocrine cells in the brain of insects and echinoderm GSS evolved independently from IGF and thus are not true orthologs, but the result of convergent evolution.

scholarly journals What have the revelations about Neanderthal DNA revealed about Homo sapiens?

2020 ◽  
Vol 83 (1) ◽  
pp. 93-107
Author(s):  
Santiago Wolnei Ferreira Guimarães ◽  
Hilton P. Silva
Keyword(s):  
Gene Flow ◽  
Morphological Traits ◽  
Common Ancestor ◽  
Homo Sapiens ◽  
Explanatory Models ◽  
The Other ◽  
Last Common Ancestor ◽  
Genetic Studies ◽  
Origin And Evolution ◽  
Out Of Africa

AbstractGenetic studies have presented increasing indications about the complexity of the interactions between Homo sapiens, Neanderthals and Denisovans, during Pleistocene. The results indicate potential replacement or admixture of the groups of hominins that lived in the same region at different times. Recently, the time of separation among these hominins in relation to the Last Common Ancestor – LCA has been reasonably well established. Events of mixing with emphasis on the Neanderthal gene flow into H. sapiens outside Africa, Denisovans into H. sapiens ancestors in Oceania and continental Asia, Neanderthals into Denisovans, as well as the origin of some phenotypic features in specific populations such as the color of the skin, eyes, hair and predisposition to develop certain kinds of diseases have also been found. The current information supports the existence of both replacement and interbreeding events, and indicates the need to revise the two main explanatory models, the Multiregional and the Out-of-Africa hypotheses, about the origin and evolution of H. sapiens and its co-relatives. There is definitely no longer the possibility of justifying only one model over the other. This paper aims to provide a brief review and update on the debate around this issue, considering the advances brought about by the recent genetic as well as morphological traits analyses.

The cranial structure of the Triconodonts

1963 ◽  
Vol 246 (727) ◽  
pp. 83-103 ◽  
Keyword(s):  
Common Ancestor ◽  
British Museum ◽  
Lateral Wall ◽  
Upper Jurassic ◽  
Last Common Ancestor ◽  
Lateral Boundary ◽  
Cranial Cavity ◽  
Chemical Methods ◽  
Mesozoic Mammals ◽  
The Brain

This paper is a study of the structure of the braincase in two closely related Mesozoic mammals: Triconodon mordax and Trioracodon ferox . They belong to the order Triconodonta, subfamily Triconodontinae, and are from the English Upper Jurassic (Purbeck). One specimen of each species was available showing cranial structure, both from the collection in the British Museum. By chemical methods, both petrosals and the sphenoid of the specimen of Triconodon and both petrosals of the specimen of Trioracodon were prepared. The material shows that the Triconodonta had a braincase of an essentially reptilian pattern. There was a persistent cavum epiptericum lying outside the ossified lateral wall (formed by the petrosal) of the braincase. The alisphenoid, forming the lateral boundary of the cavum epiptericum, formed no part of the braincase wall in this region. This was also true of the Rhaetic Morganucodon , and may have been true of all pre-Cretaceous mammals. In basic construction the braincase of these mammals differs from that of an advanced therapsid only in the narrower cavum epiptericum in the former. This difference is due to the relatively larger size of the brain in the mammal. To convert a braincase constructed in this way into that of a modern mammal either the alisphenoid would have to be lost—leading to the condition found in the monotremes—or the lateral wall of the neurocranum would have to fail to ossify—thus incorporating the cavum epiptericum in the cranial cavity in the manner typical of marsupials and placentals. Although on these grounds alone the monotreme stock need not have separated from that which gave rise to the marsupials and placentals until early in the Cretaceous, other considerations suggest that the last common ancestor lived in Triassic times at the reptilian grade of organization. There seems, however, less reason than formerly to consider Morganucodon an ancestral monotreme. Finally, a reconsideration of all the evidence shows that there was no acceleration of evolutionary rates at the time the Mammalia came into existence.

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