Topic
Encephalization
About: Encephalization is a research topic. Over the lifetime, 349 publications have been published within this topic receiving 18069 citations.
Papers published on a yearly basis
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Papers
TL;DR: These studies showed that the human brain is not exceptional in its cellular composition, as it was found to contain as many neuronal and non-neuronal cells as would be expected of a primate brain of its size, and argue in favor of a view of cognitive abilities that is centered on absolute numbers of neurons.
Abstract: The human brain has often been viewed as outstanding among mammalian brains: the most cognitively able, the largest-than-expected from body size, endowed with an overdeveloped cerebral cortex that represents over 80% of brain mass, and purportedly containing 100 billion neurons and 10× more glial cells. Such uniqueness was seemingly necessary to justify the superior cognitive abilities of humans over larger-brained mammals such as elephants and whales. However, our recent studies using a novel method to determine the cellular composition of the brain of humans and other primates as well as of rodents and insectivores show that, since different cellular scaling rules apply to the brains within these orders, brain size can no longer be considered a proxy for the number of neurons in the brain. These studies also showed that the human brain is not exceptional in its cellular composition, as it was found to contain as many neuronal and non-neuronal cells as would be expected of a primate brain of its size. Additionally, the so-called overdeveloped human cerebral cortex holds only 19% of all brain neurons, a fraction that is similar to that found in other mammals. In what regards absolute numbers of neurons, however, the human brain does have two advantages compared to other mammalian brains: compared to rodents, and probably to whales and elephants as well, it is built according to the very economical, space-saving scaling rules that apply to other primates; and, among economically built primate brains, it is the largest, hence containing the most neurons. These findings argue in favor of a view of cognitive abilities that is centered on absolute numbers of neurons, rather than on body size or encephalization, and call for a re-examination of several concepts related to the exceptionality of the human brain.
1,726 citations
TL;DR: The outstanding intelligence of humans appears to result from a combination and enhancement of properties found in non-human primates, such as theory of mind, imitation and language, rather than from 'unique' properties.
1,715 citations
TL;DR: It is shown that two independent methods of body-mass estimation yield concordant results when applied to Pleistocene Homo specimens, and on the basis of an analysis of 163 individuals, body mass in Pleistsocene Homo averaged significantly (about 10%) larger than a representative sample of living humans.
Abstract: Many dramatic changes in morphology within the genus Homo have occurred over the past 2 million years or more, including large increases in absolute brain size and decreases in postcanine dental size and skeletal robusticity. Body mass, as the 'size' variable against which other morphological features are usually judged, has been important for assessing these changes1–5. Yet past body mass estimates for Pleistocene Homo have varied greatly, sometimes by as much as 50% for the same individuals2,3,6–12. Here we show that two independent methods of body-mass estimation yield concordant results when applied to Pleistocene Homo specimens. On the basis of an analysis of 163 individuals, body mass in Pleistocene Homo averaged significantly (about 10%) larger than a representative sample of living humans. Relative to body mass, brain mass in late archaic H. sapiens (Neanderthals) was slightly smaller than in early 'anatomically modern' humans, but the major increase in encephalization within Homo occurred earlier during the Middle Pleistocene (600–150 thousand years before present (kyr BP)), preceded by a long period of stasis extending through the Early Pleistocene (1,800 kyr BP).
879 citations
TL;DR: Re-examination of brain–body size relationships for large samples of species from three major vertebrate groups now shows that there is no empirical foundation for the concept of scaling to body surface area, and it seems that brain size may be linked to maternal metabolic turnover.
Abstract: Studies of the relationship between brain size and body size in terrestrial verteberates have a long history1–4. Demonstrations of regular relationships between brain and body size across species within selected vertebrate groups serve two purposes: (1) in comparison of species of different body size, empirically recognized ‘scaling effects’ can be taken into account; (2) empirical relationships may suggest useful working hypotheses regarding functional constraints (although they cannot directly reveal casual connections). It is widely accepted5,6 that brain size is scaled to keep pace with changes in body surface area (rather than volume), and this provides the basis for many interpretations of relative brain size. Re-examination of brain–body size relationships for large samples of species from three major vertebrate groups (mammals, birds, reptiles) now shows that there is no empirical foundation for the concept of scaling to body surface area. Instead, it seems that brain size may be linked to maternal metabolic turnover. This has implications not only for assessment of relative brain size in particular species, but also for pursuing links between brain size and ‘life strategies’.
716 citations
TL;DR: Application of the simple thermoregulatory principle of increasing and decreasing body surface area/body mass in hot and cold climates, respectively, may explain the major systematic differences in body form between living and fossil hominids inhabiting tropical and higher latitude regions of the world.
Abstract: Hominids—both living and past—exhibit considerable variation in body size and shape. Both theoretical considerations and empirical observations indicate that some of this variation may be attributable to climatic adaptation. Application of the simple thermoregulatory principle of increasing and decreasing body surface area/body mass in hot and cold climates, respectively, may explain the major systematic differences in body form between living and fossil hominids inhabiting tropical and higher latitude regions of the world. Consideration of potential climatic influences on morphology has important ramifications for reconstructing body form and behavior of past hominids, interpreting geographic and temporal variability and migrational events, explaining the origins and perfection of hominid bipedalism, and better understanding changes in brain size and encephalization during hominid evolution. © 1994 Wiley-Liss, Inc.
684 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2025 | 10 |
| 2024 | 14 |
| 2023 | 27 |
| 2022 | 21 |
| 2021 | 14 |
| 2020 | 6 |