Introduction

2021 ◽  
pp. 1-4
Author(s):  
Susan D. Healy
Keyword(s):  
Natural Selection ◽  
Animal Species ◽  
Brain Size ◽  
Comparative Method ◽  
Selection Pressures ◽  
Mechanistic Explanations ◽  
The Past

This brief introductory chapter begins with the key question to be addressed in the book: why does brain size vary among animal species? It contains a short outline of the book’s contents and establishes the rationale for the examination of the evidence that has been gathered using the comparative method over the past five decades. I explain that the book will be both a review and a critique of the work that has attempted to explain which natural selection pressures led to changes in brain size. This is a focus that, to a large extent, excludes work that addresses mechanistic explanations for brain size.

Adaptation and the Brain

2021 ◽  
Author(s):  
Susan D. Healy
Keyword(s):  
Natural Selection ◽  
Selection Pressure ◽  
Technology Innovation ◽  
Brain Size ◽  
Comparative Method ◽  
Brain Regions ◽  
Evolutionary Patterns ◽  
Five Factors ◽  
Pressure Form ◽  
The Brain

The rationale for this work is to make some sort of sense of the seeming myriad of adaptive explanations for why vertebrate brains vary in size. The role that natural selection has played in brain size has been addressed using the comparative method, which allows identification of evolutionary patterns across species. One starting assumption is that brain size is a useful proxy for intelligence and therefore that large-brained animals are more intelligent than smaller-brained animals. Five classes of selection pressure form the majority of explanations: ecology, technology, innovation, sex, and sociality. After chapters in which I describe the difficulties of measuring both brain size and intelligence (cognition), I address the evidence for each of the five factors in turn, reaching the conclusion that although ecology provides the best explanations for variation in the size of brain regions, none of the factors yet offers a robust and compelling explanation for variation in whole brain size. I end by providing the steps I consider necessary to reach such an explanation, steps that I suggest are feasible, if challenging.

The Evolution of Lead Extraction

2009 ◽  
Vol 5 (1) ◽  
pp. 32
Author(s):  
Melanie Maytin ◽  
Laurence M Epstein ◽  
◽  
Keyword(s):  
Natural Selection ◽  
Lead Extraction ◽  
Significant Morbidity ◽  
Extraction Techniques ◽  
Extraction Technology ◽  
Device Management ◽  
Future Developments ◽  
The Past ◽  
New Methods ◽  
Life Threatening

Prior to the introduction of successful intravascular countertraction techniques, options for lead extraction were limited and dedicated tools were non-existent. The significant morbidity and mortality associated with these early extraction techniques limited their application to life-threatening situations such as infection and sepsis. The past 30 years have witnessed significant advances in lead extraction technology, resulting in safer and more efficacious techniques and tools. This evolution occurred out of necessity, similar to the pressure of natural selection weeding out the ineffective and highly morbid techniques while fostering the development of safe, successful and more simple methods. Future developments in lead extraction are likely to focus on new tools that will allow us to provide comprehensive device management and the design of new leads conceived to facilitate future extraction. With the development of these new methods and novel tools, the technique of lead extraction will continue to require operators that are well versed in several methods of extraction. Garnering new skills while remembering the lessons of the past will enable extraction technologies to advance without repeating previous mistakes.

The Ethical Presupposition of Historical Understanding

2017 ◽  
Vol 5 (2) ◽  
pp. 223-241
Author(s):  
Natan Elgabsi
Keyword(s):  
Comparative Method ◽  
Historical Understanding ◽  
Historical Science ◽  
Ethical Attitudes ◽  
The Past ◽  
Annales School ◽  
Ways Of Life

Abstract Discussions on Marc Bloch usually focus on The Annales School, his comparative method, or his defence of a distinct historical science. In contrast, I emphasise his seldom-investigated ideas of what historical understanding should involve. I contend that Bloch distinguishes between three different ethical attitudes in studying people and ways of life from the past: scientific passivity; critical judgements; understanding. The task of the historian amounts to understanding other worlds in their own terms. This essay is an exploration of Bloch’s methodology and what historical understanding is needed to do justice to cultures that belong to the past, both conceptually and practically.

Measuring the Selective Utilization of Animal Species by Prehistoric Human Populations

1979 ◽  
Vol 44 (1) ◽  
pp. 155-160 ◽  
Author(s):  
Bruce D. Smith
Keyword(s):  
Animal Species ◽  
Human Populations ◽  
Relative Importance ◽  
The Past

To determine the pattern of selective utilization of animal species by prehistoric human populations, it is first necessary to quantify the relative importance of species of animals in the diet of prehistoric human groups through analysis of archaeologically recovered faunal samples. These values are then compared with estimates of the relative availability of different species of animals in the environment. Such estimates of the relative availability of animal species in prehistoric habitat situations, usually quantified in terms of biomass, are obtained by projecting data from modern analog situations into the past. When attempting to reconstruct prehistoric biotic communities in this manner, it is important to be aware of a number of possible sources of bias and to evaluate and apply modern wildlife data according to a set of interrelated principles. Sources of bias and criteria for selecting modern wildlife analog data are discussed.

scholarly journals Recent Developments in Diagnosis and Care for Girls in Turner Syndrome

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Carolyn Bondy
Keyword(s):  
Turner Syndrome ◽  
Brain Size ◽  
Molecular Genetic ◽  
Oocyte Donation ◽  
Breath Holding ◽  
Chromosomal Anomalies ◽  
The Past ◽  
Molecular Tests ◽  
Effective Counseling ◽  
Recent Developments

The past decade produced important advances in molecular genetic techniques potentially supplanting the traditional cytogenetic diagnosis of Turner syndrome (TS). Rapidly evolving genomic technology is used to screen 1st trimester pregnancies for sex chromosomal anomalies including TS, and genomic approaches are suggested for the postnatal diagnosis of TS. Understanding the interpretation and limitations of new molecular tests is essential for clinicians to provide effective counseling to parents or patients impacted by these tests. Recent studies have advanced the concept that X chromosome genomic imprinting influences expression of the Turner phenotype and contributes to gender differences in brain size and coronary disease. Progress in cardiovascular MRI over the past decade has dramatically changed our view of the scope and criticality of congenital heart disease in TS. Cardiac MRI is far more effective than transthoracic echocardiography in detecting aortic valve abnormalities, descending aortic aneurysm, and partial anomalous pulmonary venous return; recent technical advances allow adequate imaging in girls as young as seven without breath holding or sedation. Finally, important developments in the area of gynecological management of girls and young women with TS are reviewed, including prognostic factors that predict spontaneous puberty and potential fertility and recent practice guidelines aimed at reducing cardiovascular risk for oocyte donation pregnancies in TS.

scholarly journals Notes on distribution and relative abundances of some animal species, and on climate in the Kruger National Park during prehistoric times

Koedoe ◽  
1989 ◽  
Vol 32 (1) ◽  
Author(s):  
Ina Plug
Keyword(s):  
National Park ◽  
Animal Species ◽  
Climatic Conditions ◽  
Kruger National Park ◽  
Archaeological Sites ◽  
Animal Population ◽  
Faunal Remains ◽  
The Past ◽  
Relative Abundances ◽  
Insight Into

Faunal remains obtained from archaeological sites in the Kruger National Park, provide valuable information on the distributions of animal species in the past. The relative abundances of some species are compared with animal population statistics of the present. The study of the faunal samples, which date from nearly 7 000 years before present until the nineteenth century, also provides insight into climatic conditions during prehistoric times.

scholarly journals Human niche construction in interdisciplinary focus

2011 ◽  
Vol 366 (1566) ◽  
pp. 785-792 ◽  
Author(s):  
Jeremy Kendal ◽  
Jamshid J. Tehrani ◽  
John Odling-Smee
Keyword(s):  
Natural Selection ◽  
Material Culture ◽  
Niche Construction ◽  
Cultural Knowledge ◽  
Causal Process ◽  
Genetic Inheritance ◽  
Selection Pressures ◽  
Ecological Inheritance ◽  
Human Niche Construction ◽  
The Social

Niche construction is an endogenous causal process in evolution, reciprocal to the causal process of natural selection. It works by adding ecological inheritance , comprising the inheritance of natural selection pressures previously modified by niche construction, to genetic inheritance in evolution. Human niche construction modifies selection pressures in environments in ways that affect both human evolution, and the evolution of other species. Human ecological inheritance is exceptionally potent because it includes the social transmission and inheritance of cultural knowledge, and material culture. Human genetic inheritance in combination with human cultural inheritance thus provides a basis for gene–culture coevolution, and multivariate dynamics in cultural evolution. Niche construction theory potentially integrates the biological and social aspects of the human sciences. We elaborate on these processes, and provide brief introductions to each of the papers published in this theme issue.

Introduction

2018 ◽  
pp. 1-17
Author(s):  
Matthew D. O'Hara
Keyword(s):  
Latin America ◽  
Case Studies ◽  
Historical Development ◽  
Colonial Mexico ◽  
Historical Case ◽  
Colonial Era ◽  
Historical Method ◽  
The Past ◽  
The Relationship

This introductory chapter provides an overview of the analysis of time experience and futuremaking through historical case studies in colonial Mexico. Colonial Mexico developed a culture of innovation, human aspiration, and futuremaking that was subsequently forgotten in part because it did not fit with later definitions of modernity and innovation as secular phenomena and things untethered to the past or tradition. This choice of historical method and topics is driven by a desire to step outside some of the dominant paradigms in the study of Latin America and colonialism in general. Examining the relationship between past, present, and future offers a way to reconsider Mexico's colonial era, its subsequent historical development, and how people have understood that history.

scholarly journals A Short Report on the Extent of Stone Handling Behavior Across Otter Species

2021 ◽  
Vol 8 (1) ◽  
pp. 15-22
Author(s):  
Elisa Bandini
Keyword(s):  
Tool Use ◽  
Animal Species ◽  
Potential Functions ◽  
Play Behavior ◽  
Stone Tool ◽  
Short Report ◽  
Selection Pressures ◽  
Future Studies ◽  
Macaque Species

Animal stone-handling behavior (SH) has been recorded in detail only in primates, mainly across macaque species. The purpose(s) of SH are still unknown, yet various hypotheses have been suggested, including that it is a misdirected behavior when hungry and/or a play behavior that aids individuals' motor and stone tool-use development. SH has also been observed across both wild and captive otter species, but no overview report of the extent of this behavior across otter species has been published yet. To fill this gap in the literature, we contacted wild and captive otter researchers and keepers to enquire directly on SH in the species they work with. We accepted anecdotal reports in this first review of the behavior. Using the reports and anecdotes thus obtained, we compiled the first list of otter species that show SH. We found that most (10 out of 13) of currently known otter species practice SH. Therefore, similarly to macaques, SH is also common in otters and occurs in the majority of species. Future studies should focus on replicating these findings and further investigating the potential functions and selection pressures of SH in otters and other animal species.

scholarly journals Allometry unleashed: an adaptationist approach of brain scaling in mammalian evolution

2019 ◽  
Author(s):  
Romain Willemet
Keyword(s):  
Body Size ◽  
Allometric Scaling ◽  
Species Differences ◽  
Brain Size ◽  
Brain Evolution ◽  
Neural Systems ◽  
Selection Pressures ◽  
Number Of Factors ◽  
Functional Consequences ◽  
Main Factor

The idea that allometry in the context of brain evolution mainly result from constraints channelling the scaling of brain components is deeply embedded in the field of comparative neurobiology. Constraints, however, only prevent or limit changes, and cannot explain why these changes happen in the first place. In fact, considering allometry as a lack of change may be one of the reasons why, after more than a century of research, there is still no satisfactory explanatory framework for the understanding of species differences in brain size and composition in mammals. The present paper attempts to tackle this issue by adopting an adaptationist approach to examine the factors behind the evolution of brain components. In particular, the model presented here aims to explain the presence of patterns of covariation among brain components found within major taxa, and the differences between taxa. The key determinant of these patterns of covariation within a taxon-cerebrotype (groups of species whose brains present a number of similarities at the physiological and anatomical levels) seems to be the presence of taxon-specific patterns of selection pressures targeting the functional and structural properties of neural components or systems. Species within a taxon share most of the selection pressures, but their levels scale with a number of factors that are often related to body size. The size and composition of neural systems respond to these selection pressures via a number of evolutionary scenarios, which are discussed here. Adaptation, rather than, as generally assumed, developmental or functional constraints, thus appears to be the main factor behind the allometric scaling of brain components. The fact that the selection pressures acting on the size of brain components form a pattern that is specific to each taxon accounts for the peculiar relationship between body size, brain size and composition, and behavioural capabilities characterizing each taxon. While it is important to avoid repeating the errors of the “Panglossian paradigm”, the elements presented here suggests that an adaptationist approach may shed a new light on the factors underlying, and the functional consequences of, species differences in brain size and composition.

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