scholarly journals What Studying the Songs of a Distant Primate Relative Can Teach Us About Ourselves

2021 ◽  
Vol 9 ◽  
Author(s):  
Dena Jane Clink
Keyword(s):  
Common Ancestor ◽  
Human Language ◽  
Modern Humans ◽  
Living Things ◽  
Vocal Interactions

Tarsiers are nocturnal animals. They have eyes that are heavier than their brains. They eat only insects and other living things. Tarsiers are primates, just like humans. And some species of tarsiers sing! Tarsier songs and human language are different in many ways. But if we study the similarities, it may help us better understand human language. In our study, we recorded singing tarsiers on the Indonesian island of Sulawesi. With the help of computers, we found that we could tell individual tarsiers apart based on their songs. Being able to recognize who is singing from far away may be an important function of tarsier songs. We also found that if a female speeds up her song, then the male speeds up his song, too. The ability to modify vocal output based on what others are doing is a universal in human language. Our results show that tarsiers (like humans) can change their vocalizations based on what their partner is doing. The fact that tarsiers and humans are both able to do this indicates that their common ancestor probably had this ability. Our results add support to the idea that flexibility in vocal interactions evolved long before the appearance of modern humans.

Clash of signs: Putting bilingualism back into language evolution

2020 ◽  
Author(s):  
Steven Samuel
Keyword(s):  
Language Evolution ◽  
Modern Human ◽  
Alarm Calls ◽  
Bilingual Children ◽  
Human Language ◽  
Typically Developing ◽  
Typically Developing Children ◽  
Modern Humans ◽  
The Real ◽  
Multiple Languages

Research and thinking into the cognitive aspects of language evolution has usually attempted to account for how the capacity for learning even one modern human language developed. Bilingualism has perhaps been thought of as something to think about only once the ‘real’ puzzle of monolingualism is solved, but this would assume in turn (and without evidence) that bilingualism evolved after monolingualism. All typically-developing children (and adults) are capable of learning multiple languages, and the majority of modern humans are at least bilingual. In this paper I ask whether by skipping bilingualism out of language evolution we have missed a trick. I propose that exposure to synonymous signs, such as food and alarm calls, are a necessary precondition for the abstracting away of sound from referent. In support of this possibility is evidence that modern day bilingual children are better at breaking this ‘word magic’ spell. More generally, language evolution should be viewed through the lens of bilingualism, as this is the end state we are attempting to explain.

scholarly journals The evolutionary history of human spindle genes includes back-and-forth gene flow with Neandertals

2021 ◽  
Author(s):  
Stéphane Peyrégne ◽  
Janet Kelso ◽  
Benjamin Marco Peter ◽  
Svante Pääbo
Keyword(s):  
Gene Flow ◽  
Evolutionary History ◽  
Common Ancestor ◽  
Modern Human ◽  
Modern Humans ◽  
Ancestral Gene ◽  
Cytoskeletal Structure ◽  
Spindle Apparatus ◽  
History Of ◽  
Segregation Of Chromosomes

Proteins associated with the spindle apparatus, a cytoskeletal structure that ensures the proper segregation of chromosomes during cell division, experienced an unusual number of amino acid substitutions in modern humans after the split from the ancestors of Neandertals and Denisovans. Here, we analyze the history of these substitutions and show that some of the genes in which they occur may have been targets of positive selection. We also find that the two changes in the kinetochore scaffold 1 (KNL1) protein, previously believed to be specific to modern humans, were present in some Neandertals. We show that the KNL1 gene of these Neandertals shared a common ancestor with present-day Africans about 200,000 years ago due to gene flow from the ancestors (or relatives) of modern humans into Neandertals. Subsequently, some non-Africans inherited this modern human-like gene variant from Neandertals, but none inherited the ancestral gene variants. These results add to the growing evidence of early contacts between modern humans and archaic groups in Eurasia and illustrate the intricate relationships among these groups.

scholarly journals The Most Recent Common Ancestor of Modern Humans was Born in Eurasia

2020 ◽  
Author(s):  
vicente cabrera
Keyword(s):  
Human Evolution ◽  
Genome Sequencing ◽  
Common Ancestor ◽  
Recent Common Ancestor ◽  
Whole Genome ◽  
African Origin ◽  
Modern Humans ◽  
Most Recent Common Ancestor ◽  
History Of ◽  
New Vision

Ancient DNA has given a new vision to the recent history of human evolution. However, by always relying on the information provided by whole genome sequencing, some relevant relationships between modern humans and its archaic relatives have been misinterpreted by hybridization and recombination causes. In contrast, the congruent phylogeny, obtained from non-recombinant uniparental markers, indicates that humans and Neanderthals are sister subspecies, and that the most recent common ancestor of modern humans was not of African origin but Eurasian.

Visual Pigments and Photoreceptors

2014 ◽  
Author(s):  
Thomas W. Cronin ◽  
Sönke Johnsen ◽  
N. Justin Marshall ◽  
Eric J. Warrant
Keyword(s):  
Hydrothermal Vent ◽  
Common Ancestor ◽  
Visual Pigments ◽  
Ecological Adaptation ◽  
Life Stages ◽  
Single Family ◽  
Developmental States ◽  
Visual Systems ◽  
Living Things

This chapter focuses on visual pigments and photoreceptors. In living things, photoreception inevitably begins with a photochemical event—a molecule intercepts a photon of light and is somehow changed. Various molecules, generally known as photopigments, perform this function in animals and plants. The molecules involved in vision are called visual pigments. In all animals, vision ultimately depends on a single family of proteins that all have descended from one common ancestor—these are the opsins. The chapter cites the hydrothermal vent crab as a good example of how changes of visual pigments appearing in various developmental states reflect ecological adaptation. The animal's life stages require visual systems sampling opposite ends of the visual spectrum.

What Can the Y Chromosome Tell Us about the Origin of Modern Humans?

2004 ◽  
Author(s):  
Chris Tyler-Smith
Keyword(s):  
Y Chromosome ◽  
Common Ancestor ◽  
Population Characteristics ◽  
Pseudoautosomal Region ◽  
Modern Humans ◽  
Homology Region ◽  
Genetic History ◽  
Trace Back ◽  
Origin Of Modern Humans

This chapter outlines the peculiar genetic history and population characteristics of the Y chromosome, including the interaction with the X. The small size of the Y and its sex-limited transmission make it at first sight an unlikely vehicle for the determining characteristic of the species. Human and ape Y lineages are generally believed to have split about 5–7 million years ago, while extant human Y lineages trace back to a common ancestor that probably lived between 40 and 200 thousand years ago. Between these dates, two substantial segments of DNA on the Y chromosome were duplicated on the Y: the Yq pseudoautosomal region and the Xq/Yp homology region. The former does not contain any good candidate speciation genes but the latter may. The Xq-Yp transposition probably occurred soon after the ape-human split and, at the same time or subsequently, was divided in two by an inversion.

Territorial song and facial gesture: A language precursor in apes

1999 ◽  
Vol 22 (3) ◽  
pp. 572-573 ◽  
Author(s):  
Maria Ujhelyi
Keyword(s):  
Communication System ◽  
Common Ancestor ◽  
Voluntary Control ◽  
Human Language ◽  
Group Members ◽  
The Common ◽  
Territorial Song ◽  
Call Repertoire

The natural communication system of chimpanzees has some unique characteristics rooted in two possible ways of producing call variants in primates. The chimpanzee call repertoire contains variants available to all group members. The transfer presupposes voluntary control and learnability. Chimpanzee vocalization (or its homologue in the common ancestor of chimpanzee and man) seems to represent a real precursor of human language.

scholarly journals Genetic distance and social compatibility in the aggregation behavior of Japanese toad tadpoles

2018 ◽  
Author(s):  
Kazuko Hase ◽  
Masato S. Abe ◽  
Masakazu Shimada
Keyword(s):  
Mhc Class Ii ◽  
Common Ancestor ◽  
Functional Trait ◽  
Genetic Distances ◽  
Aggregation Behavior ◽  
Social Aggregation ◽  
Histocompatibility Complex ◽  
Living Things ◽  
Group Members ◽  
Quantitative Analyses

AbstractFrom microorganism to vertebrates, living things often exhibit social aggregation. One of anuran larvae, dark-bodied toad tadpoles (genus Bufo) are known to aggregate against predators. When individuals share genes from a common ancestor for whom social aggregation was a functional trait, they are also likely to share common recognition cues regarding association preferences, while greater genetic distances make cohesive aggregation difficult. In this study, we conducted quantitative analyses to examine aggregation behavior among three lineages of toad tadpoles: Bufo japonicus japonicus, B. japonicus formosus, and B. gargarizans miyakonis. To determine whether there is a correlation between cohesiveness and genetic similarity among group members, we conducted an aggregation test using 42 cohorts consisting of combinations drawn from a laboratory-reared set belonging to distinct clutches. As genetic indices, we used mitochondrial DNA (mtDNA) and major histocompatibility complex (MHC) class II alleles. The results clearly indicated that aggregation behavior in toad tadpoles is directly influenced by genetic distances based on mtDNA sequences and not on MHC haplotypes. Cohesiveness among heterogeneous tadpoles is negatively correlated with the geographic dispersal of groups. Our findings suggest that social incompatibility among toad tadpoles reflects phylogenetic relationships.

scholarly journals The quantity of Neanderthal DNA in modern humans: a reanalysis relaxing the assumption of constant mutation rate

2016 ◽  
Author(s):  
William Amos
Keyword(s):  
Mutation Rate ◽  
Common Ancestor ◽  
Alternative Hypothesis ◽  
Large Contribution ◽  
Modern Humans ◽  
Out Of Africa ◽  
Loss Of Diversity ◽  
Induced Changes

AbstractFew now dispute that a few percent of the DNA of non-African humans is a legacy of interbreeding with Neanderthals. However, heterozygosity and mutation rate appear to be linked such that the loss of diversity associated with humans migrating out of Africa caused a mutational slowdown, allowing Africans to diverge more from both our common ancestor and Neanderthals. Here I use a range of contrasting tests aimed at distinguishing between mutation slowdown and introgression as explanations for the higher rates of base-sharing between non-Africans and Neanderthals. In every instance the mutation slowdown hypothesis fits better. Thus, while some interbreeding likely occurred, as evidenced by the finding of skeletons of admixed individuals, adaptive genes and the apparently large contribution of Denisovan DNA to Oceanian genomes, my results challenge the idea that non-Africans generally carry an appreciable Neanderthal legacy. My analysis shows that inferences about introgression may be unreliable unless variation in mutation rate linked to demographically induced changes in heterozygosity can be excluded as an alternative hypothesis.

1. Introduction

2019 ◽  
pp. 1-6
Author(s):  
Bernard Wood
Keyword(s):  
Evolutionary History ◽  
Common Ancestor ◽  
Tree Of Life ◽  
Recent Common Ancestor ◽  
Modern Humans ◽  
Most Recent Common Ancestor ◽  
Last Stage ◽  
Living Organisms

All living organisms are situated on a Tree of Life that began around three billion years ago. The Introduction explains that this VSI focuses on the last stage of the human evolutionary journey, the stage between the most recent common ancestor shared by chimpanzees/bonobos and modern humans (around six to eight million years ago) and present-day modern humans. The three objectives of this VSI are to try and explain how palaeoanthropologists go about the task of improving our understanding of human evolutionary history; to convey a sense of what we think we know about human evolutionary history; and to show where the major gaps in our knowledge are.

SPECIAL CONSIDERATION FOR HUMANS

PEDIATRICS ◽  
1978 ◽  
Vol 61 (2) ◽  
pp. 188-188
Author(s):  
R. Dawkins ◽  
Keyword(s):  
Experimental Evidence ◽  
Legal Protection ◽  
Moral Consideration ◽  
Special Consideration ◽  
Human Language ◽  
Human Species ◽  
Human Foetus ◽  
Living Things ◽  
Human Ethics ◽  
Interesting Corollary

Recently there has been a reaction against racialism and patriotism, and a tendency to substitute the whole human species as the object of our fellow feeling. This humanist broadening of the target of our altruism has an interesting corollary.... The feeling that members of one's own species deserve special moral consideration as compared with members of other species is old and deep. Killing people outside war is the most seriously regarded crime ordinarily committed. The only thing more strongly forbidden by our culture is eating people (even if they are already dead). We enjoy eating members of other species, however. Many of us shrink from judicial execution of even the most horrible human criminals, while we cheerfully countenance the shooting of other harmless species as a means of recreation and amusement. A human foetus, with no more human feeling than an amoeba, enjoys a reverence and legal protection far in excess of those granted to an adult chimpanzee. Yet the chimp feels and thinks and-according to recent experimental evidence-may even be capable of learning a form of human language. The foetus belongs to our own species, and is instantly accorded special privileges and rights because of it.... The muddle in human ethics [is] over the level at which altruism is desirable-family, nation, race, species, or all living things....

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