scholarly journals A paradigm for the evolution of human features: Apes trapped on barren volcanic islands

2020 ◽  
Vol 13 ◽  
Author(s):  
Allan George Krill
Keyword(s):  
Fatty Acid ◽  
Human Genome ◽  
Sea Level ◽  
Human Evolution ◽  
Homo Sapiens ◽  
Brain Size ◽  
Central Africa ◽  
Land Bridge ◽  
Terrestrial Environments ◽  
Volcanic Islands

The aquatic ape hypothesis for human evolution can account for all the traits that distinguish humans from chimpanzees. This scientific paradigm has been considered impossible. It would require that human ancestors maintained a semiaquatic lifestyle for millions of years, whereas hominin fossils indicate relatively dry terrestrial environments. Here I propose a marine aquatic evolution that is speculative, but compatible with all the fossil and genetic evidence. In this hypothesis, hominins evolved from chimpanzee-like apes that became stranded on proto-Bioko — new volcanic islands with no terrestrial foods available. The apes were forced to eat shellfish and seaweed. From wading in water on two legs to obtain food, their bodies evolved to become bipedal. Naked skin, blubber, and protruding noses were also aquatic adaptations. Brain-size increase resulted from marine fatty acid DHA. Some of these hominins escaped to mainland Africa and their bipedal descendants are recorded at the famous fossil sites. The volcanic islands grew and evolved into Bioko, and the hominins that remained there evolved into Homo sapiens. They gave up their marine diet and semiaquatic habitat after food became available on the evolving island. Then, during one of the low sea-level stands in the Pleistocene epoch, humans walked to the mainland on the emergent Bioko land bridge. Unlike earlier aquatic ape ideas, the Bioko scenario can be tested by DNA. If the human genome includes a retrovirus that is otherwise only found in endemic animals on Bioko, it would show that our ancestors came from there. Unfortunately, Bioko and west-central Africa are not interesting to traditional paleoanthropologists, because they do not contain fossils.

scholarly journals Two interpretations of human evolution: Essentialism and Darwinism

2009 ◽  
Vol 72 (1) ◽  
pp. 66-80 ◽  
Author(s):  
Maciej Henneberg
Keyword(s):  
Human Evolution ◽  
Scientific Inquiry ◽  
Theoretical Basis ◽  
Homo Sapiens ◽  
Brain Size ◽  
Single Species ◽  
Continuous Change ◽  
Basic Principles ◽  
Hominin Evolution ◽  
Data Points

Two interpretations of human evolution: Essentialism and DarwinismDespite intensive studies of a large number of fossils discovered during the 20th century there is no consensus as to the interpretation of the process of hominin evolution. Some authors see as many as six genera and some 17 species, while others argue for a single lineage from Plio/Pleistocene until today. Such diversity of interpretations of the same facts indicates lack of a uniform theoretical basis underlying studies of human evolution. Debates can be resolved using basic principles of scientific inquiry - parsimony and falsification of null hypotheses. Hypothesis testing is now possible with respect to the evolution of basic hominin characteristics such as brain size, body size and the size of the dentition that have sample sizes of a few hundred individual data points each. These characters display a continuous change with time. Analyses of variance do not falsify the null hypothesis of the existence of only one species at any time - variances around regression lines on time do not differ from the variance observed in the single species of Homo sapiens - distributions of residuals are normal. Thus, splitting of the hominin lineage into coeval species can only be based on descriptive characteristics that are liable to errors of subjective judgment.

On Diet, Energy Metabolism, and Brain Size in Human Evolution

1996 ◽  
Vol 37 (1) ◽  
pp. 125-129 ◽  
Author(s):  
William R. Leonard ◽  
Marcia L. Robertson ◽  
Leslie C. Aiello ◽  
Peter Wheeler
Keyword(s):  
Energy Metabolism ◽  
Human Evolution ◽  
Brain Size

Seven Steps in the Evolution of the Human Imagination

2007 ◽  
Author(s):  
STEVEN MITHEN
Keyword(s):  
Cultural Change ◽  
Homo Sapiens ◽  
Brain Size ◽  
Modern Human ◽  
Clear Picture ◽  
Modern Humans ◽  
Creative Imagination ◽  
African Apes ◽  
Ways Of Thinking ◽  
Forms Of Knowledge

The modern human is a product of six million years of evolution wherein it is assumed that the ancestor of man resembles that of a chimpanzee. This assumption is based on the similarities of the ape-like brain size and post-cranial characteristics of the earliest hominid species to chimpanzees. Whilst it is unclear whether chimpanzees share the same foresight and contemplation of alternatives as with humans, it is nevertheless clear that chimpanzees lack creative imagination — an aspect of modern human imagination that sets humanity apart from its hominid ancestors. Creative imagination pertains to the ability to combine different forms of knowledge and ways of thinking to form creative and novel ideas. This chapter discusses seven critical steps in the evolution of the human imagination. These steps provide a clear picture of the gradual emergence of creative imagination in humans from their primitive origins as Homo sapiens some 200,000 years ago. This chronological evolution of the imaginative mind of humans involves both biological and cultural change that began soon after the divergence of the two lineages that led to modern humans and African apes.

Constraints on Social Networks

2010 ◽  
Author(s):  
Sam G. B. Roberts
Keyword(s):  
Social Networks ◽  
Social Relationships ◽  
Human Evolution ◽  
Upper Bound ◽  
Brain Size ◽  
Network Approach ◽  
Cognitive Constraints ◽  
Hominin Evolution ◽  
Over Time ◽  
Size And Structure

In both modern humans and non-human primates, time and cognitive constraints place an upper bound on the number of social relationships an individual can maintain at a given level of intensity. Similar constraints are likely to have operated throughout hominin evolution, shaping the size and structure of social networks. One of the key trends in human evolution, alongside an increase in brain size, is likely to have been an increase in group size, resulting in a larger number of social relationships that would have to be maintained over time. The network approach demonstrates that relationships should not be viewed as dyadic ties between two individuals, but as embedded within a larger network of ties between network members. Together with relationships based on kinship, this may have allowed for larger groups to be maintained among hominins than would be possible if such networks were based purely on dyadic ties between individuals.

The Origin of Modern Atolls: Challenging Darwin's Deeply Ingrained Theory

2021 ◽  
Vol 13 (1) ◽  
pp. 537-573 ◽  
Author(s):  
André W. Droxler ◽  
Stéphan J. Jorry
Keyword(s):  
Sea Level ◽  
Late Quaternary ◽  
Direct Interaction ◽  
Evolutionary Model ◽  
Reef Growth ◽  
Sea Level Fluctuations ◽  
Fringing Reefs ◽  
Volcanic Islands ◽  
Karst Model ◽  
The Tropical Pacific

In 1842, Darwin identified three types of reefs: fringing reefs, which are directly attached to volcanic islands; barrier reefs, which are separated from volcanic islands by lagoons; and ring reefs, which enclose only a lagoon and are defined as atolls. Moreover, he linked these reef types through an evolutionary model in which an atoll is the logical end point of a subsiding volcanic edifice, as he was unaware of Quaternary glaciations. As an alternative, starting in the 1930s, several authors proposed the antecedent karst model; in this model, atolls formed as a direct interaction between subsidence and karst dissolution that occurred preferentially in the bank interiors rather than on their margins through exposure during glacial lowstands of sea level. Atolls then developed during deglacial reflooding of the glacial karstic morphologies by preferential stacked coral-reef growth along their margins. Here, a comprehensive new model is proposed, based on the antecedent karst model and well-established sea-level fluctuations during the last 5 million years, by demonstrating that most modern atolls from the Maldives Archipelago and from the tropical Pacific and southwest Indian Oceans are rooted on top of late Pliocene flat-topped banks. The volcanic basement, therefore, has had no influence on the late Quaternary development of these flat-topped banks into modern atolls. During the multiple glacial sea-level lowstands that intensified throughout the Quaternary, the tops of these banks were karstified; then, during each of the five mid-to-late Brunhes deglaciations, coral reoccupied their raised margins and grew vertically, keeping up with sea-level rise and creating the modern atolls.

Comment on "Ongoing Adaptive Evolution of ASPM, a Brain Size Determinant in Homo sapiens"

Science ◽  
2007 ◽  
Vol 316 (5823) ◽  
pp. 370b-370b ◽  
Author(s):  
F. Yu ◽  
R. S. Hill ◽  
S. F. Schaffner ◽  
P. C. Sabeti ◽  
E. T. Wang ◽  
...  
Keyword(s):  
Adaptive Evolution ◽  
Homo Sapiens ◽  
Brain Size

Estimating soilpCO2using paleosol carbonates: implications for the relationship between primary productivity and faunal richness in ancient terrestrial ecosystems

Paleobiology ◽  
2012 ◽  
Vol 38 (4) ◽  
pp. 585-604 ◽  
Author(s):  
Timothy S. Myers ◽  
Neil J. Tabor ◽  
Louis L. Jacobs ◽  
Octávio Mateus
Keyword(s):  
Organic Matter ◽  
Primary Productivity ◽  
Western Europe ◽  
Central Africa ◽  
Terrestrial Ecosystems ◽  
Upper Jurassic ◽  
Morrison Formation ◽  
Positive Correlation ◽  
Terrestrial Environments ◽  
Ancient Ecosystems

In this paper we present a method for estimating soilpCO2in ancient environments using the measured carbon-isotope values of pedogenic carbonates and plant-derived organic matter. The validity of soilpCO2estimates proves to be highly dependent on the organic δ13C values used in the calculations. Organic matter should be sourced from the same paleosol profiles as sampled carbonates to yield the most reliable estimates of soilpCO2. In order to demonstrate the potential use of soilpCO2estimates in paleoecological and paleoenvironmental studies, we compare samples from three Upper Jurassic localities. SoilpCO2estimates, interpreted as a qualitative indicator of primary paleoproductivity, are used to rank the Late Jurassic terrestrial environments represented by the Morrison Formation in western North America, the informally named Lourinhã formation in Western Europe, and the Stanleyville Group in Central Africa. Because modern terrestrial environments show a positive correlation between primary productivity and faunal richness, a similar relationship is expected in ancient ecosystems. When the relative paleoproductivity levels inferred for each study area are compared with estimates of dinosaur generic richness, a positive correlation emerges. Both the Morrison and Lourinhã formations have high inferred productivity levels and high estimated faunal richness. In contrast, the Stanleyville Group appears to have had low primary productivity and low faunal richness. Paleoclimatic data available for each study area indicate that both productivity and faunal richness are positively linked to water availability, as observed in modern terrestrial ecosystems.

scholarly journals Bonobos voluntarily hand food to others but not toys or tools

2018 ◽  
Vol 285 (1886) ◽  
pp. 20181536 ◽  
Author(s):  
Christopher Krupenye ◽  
Jingzhi Tan ◽  
Brian Hare
Keyword(s):  
Human Evolution ◽  
Brain Size ◽  
Active Form ◽  
Great Apes ◽  
The Other ◽  
Controlled Experiments ◽  
Hunter Gatherers ◽  
Food Transfer ◽  
Common Descent ◽  
Food Items

A key feature of human prosociality is direct transfers , the most active form of sharing in which donors voluntarily hand over resources in their possession . Direct transfers buffer hunter-gatherers against foraging shortfalls. The emergence and elaboration of this behaviour thus likely played a key role in human evolution by promoting cooperative interdependence and ensuring that humans' growing energetic needs (e.g. for increasing brain size) were more reliably met. According to the strong prosociality hypothesis , among great apes only humans exhibit sufficiently strong prosocial motivations to directly transfer food. The versatile prosociality hypothesis suggests instead that while other apes may make transfers in constrained settings, only humans share flexibly across food and non-food contexts. In controlled experiments, chimpanzees typically transfer objects but not food, supporting both hypotheses. In this paper, we show in two experiments that bonobos directly transfer food but not non-food items. These findings show that, in some contexts, bonobos exhibit a human-like motivation for direct food transfer. However, humans share across a far wider range of contexts, lending support to the versatile prosociality hypothesis. Our species' unusual prosocial flexibility is likely built on a prosocial foundation we share through common descent with the other apes.

Human Evolution

1984 ◽  
Vol 8 ◽  
pp. 182-198
Author(s):  
Catherine Badgley
Keyword(s):  
Human Evolution ◽  
Evolutionary History ◽  
Pan Paniscus ◽  
Homo Sapiens ◽  
Great Apes ◽  
Sister Group ◽  
The Family ◽  
History Of ◽  
Living Species ◽  
Single Living

The evolutionary history of humans is well understood in outline, compared to that of many other groups of mammals. But human evolution remains enigmatic in its details, and these are compelling both scientifically and personally because they relate to the biological uniqueness of humans. Humans are placed in the primate family Hominidae, which, in traditional classifications, contains a single living species, Homo sapiens. The closest living relatives of humans are great apes: the chimpanzees Pan paniscus and Pan troglodytes, the gorilla Gorilla gorilla, and the orangutan Pongo pygmaeus. These apes have traditionally been placed in the family Pongidae as the sister group of Hominidae. Living Hominidae and Pongidae, together with Hylobatidae (gibbons) comprise the modern representatives of the primate suborder Hominoidea.

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