The Endocranial Cavity of Oviraptorosaur Dinosaurs and the Increasingly Complex, Deep History of the Avian Brain

2018 ◽  
Vol 91 (3) ◽  
pp. 125-135 ◽  
Author(s):  
Amy M. Balanoff ◽  
Mark A. Norell ◽  
Aneila V.C. Hogan ◽  
Gabriel S. Bever
Keyword(s):  
Evolutionary Biology ◽  
Comparative Biology ◽  
Avian Brain ◽  
Dynamic Nature ◽  
Evolutionary Origins ◽  
History Of ◽  
Character Complexes ◽  
Long Stem ◽  
Fossil Data ◽  
The Brain

Unraveling the origins of the character complexes diagnosing major crown clades is one of the greatest challenges in evolutionary biology. These origination events tend to optimize along extraordinarily long stem lineages where the comparative biology of extant lineages is relatively weak in its heuristic power. Here we add to a growing paleontological literature on the evolutionary origins of the modern avi an brain by describing the endocranial casts of two oviraptorosaur dinosaurs, Citipati osmolskae and Khaan mckennai. These fossil data confirm the antiquity of several avian features, including the expanded cerebrum. They also extend our appreciation of both the inherent variability in the brain-skull relationship along the avian stem and the dynamic nature of these crown characters in the earliest history of their expression.

The naked ape as an evolutionary model, 50 years later

2018 ◽  
Vol 68 (3) ◽  
pp. 227-246
Author(s):  
Nico M. van Straalen
Keyword(s):  
Natural Selection ◽  
Evolutionary Biology ◽  
Evolutionary Model ◽  
Developmental Constraints ◽  
Body Hair ◽  
Product Evolution ◽  
Adaptive Explanation ◽  
History Of ◽  
Popular Texts ◽  
The Brain

AbstractEvolution acts through a combination of four different drivers: (1) mutation, (2) selection, (3) genetic drift, and (4) developmental constraints. There is a tendency among some biologists to frame evolution as the sole result of natural selection, and this tendency is reinforced by many popular texts. “The Naked Ape” by Desmond Morris, published 50 years ago, is no exception. In this paper I argue that evolutionary biology is much richer than natural selection alone. I illustrate this by reconstructing the evolutionary history of five different organs of the human body: foot, pelvis, scrotum, hand and brain. Factors like developmental tinkering, by-product evolution, exaptation and heterochrony are powerful forces for body-plan innovations and the appearance of such innovations in human ancestors does not always require an adaptive explanation. While Morris explained the lack of body hair in the human species by sexual selection, I argue that molecular tinkering of regulatory genes expressed in the brain, followed by positive selection for neotenic features, may have been the driving factor, with loss of body hair as a secondary consequence.

The Evolution of an Idea

2020 ◽  
pp. 29-47
Author(s):  
Dominic D. P. Johnson
Keyword(s):  
Social Sciences ◽  
International Relations ◽  
Evolutionary Biology ◽  
Cognitive Biases ◽  
Evolutionary Approach ◽  
Psychological Phenomena ◽  
Selective Pressures ◽  
The Social ◽  
History Of ◽  
The Brain

This chapter considers how and why international relations might benefit from an evolutionary approach. It explains the evolutionary biology's long history of misunderstanding and resistance in the social sciences since the “sociobiology” debate of the 1970s. It also reviews how the natural and social sciences have both moved on since the 1970s, including the promise for a future of mutual collaboration on strategic instincts. The chapter focuses on evolutionary biology to understand the origins and functions of cognitive biases and comprehend the selective pressures that shaped the brain in the first place. It addresses the question of whether psychological phenomena originate from nature or nurture.

Evolution of Biomineralization

1989 ◽  
Author(s):  
Heinz A. Lowenstam ◽  
Stephen Weiner
Keyword(s):  
Fossil Record ◽  
Evolutionary Biology ◽  
Molecular Structures ◽  
Comparative Biology ◽  
Crucial Importance ◽  
Hard Part ◽  
History Of ◽  
Acidic Proteins ◽  
Living Organisms ◽  
Time And Being

Biomineralization among living organisms is widespread, occurring in both prokaryotes and eukaryotes. It is diverse with some 60 or so minerals known to be formed by organisms under a wide variety of conditions. They are deposited at many different locations both inside and outside cells. Biomineralization occurs on such an enormous scale that it influences processes in the biosphere itself. It is, therefore, of interest to determine how this all came about—the evolution of biomineralization. The evolutionary history of biomineralization is a fascinating subject in its own right, which is the primary reason for including it in this book. However, a well-substantiated understanding of this subject is also of crucial importance to the interpretation of many aspects of research into the mechanisms of biomineralization in living organisms. An example is the observation by Veis et al. (1986) that antibodies raised against the rat incisor acidic proteins, phosphophoryns, crossreact with proteins extracted from a sea urchin test. The proteins presumably share some similar molecular structures. Did they inherit them from a common ancestor or did they evolve independently from each other to fulfill similar functions? This type of question can be asked about many comparative studies in biomineralization between phyla or even within lower taxa of the same phyla. As long as we do not have answers to these questions, the powerful tool of comparative biology in biomineralization is compromised. Studying the evolution of biomineralization has one enormous advantage over many other topics in evolutionary biology; the very material that we are interested in has the best chance of surviving the vagaries of time and being preserved in the fossil record. The fossil record at least during the last 600 million years or so is, for the most part, a documentation of remnants of the history of mineralized hard part formation by organisms. Thus, the evolution of biomineralization is one topic that can, and that should be based on the direct documentation of the fossil record. This is the way it is presented in this chapter. The corollary of this statement is also worth considering. The fossil record should be interpreted bearing in mind the evolution of biomineralization.

Cutthroat Trout: Evolutionary Biology and Taxonomy

2018 ◽  
Keyword(s):  
Phylogenetic Relationships ◽  
Evolutionary Biology ◽  
Sequence Data ◽  
Cutthroat Trout ◽  
Future Research ◽  
Oncorhynchus Clarkii ◽  
Mtdna Phylogeny ◽  
History Of ◽  
Phylogenetic Hypotheses ◽  
Fossil Data

<em>Abstract</em>.—North American trout have undergone a long and complicated taxonomic history and this holds for taxonomic designations of Cutthroat Trout <em>Oncorhynchus clarkii</em>. Current Cutthroat Trout taxonomy recognizes a monophyletic species comprising 11–16 subspecies. The complex geological and climatic history of western North America is postulated to have strongly influenced differentiation among Cutthroat Trout subspecies. Early studies relied on morphological and meristic data in conjunction with fossil data and known aquatic connections within and among hydrological basins to infer the phylogenetic history of Cutthroat Trout. More recently, molecular studies incorporating karyotypes, allozymes, restriction fragment length polymorphisms, and mitochondrial DNA (mtDNA) sequence data have tested these early phylogenetic hypotheses and yielded additional insights into Cutthroat Trout evolution, although some phylogenetic relationships remain unresolved. In this study, we analyzed DNA sequence data from approximately half of the mitochondrial genome (8,057 base pairs) to better resolve phylogenetic relationships and estimate divergence times among Cutthroat Trout lineages. Herein, we present a well-resolved mtDNA phylogeny and discuss Cutthroat Trout evolution in a phylogeographic framework, as well as clarify current taxonomic implications and make recommendations for future research directions.

scholarly journals L2HGDH Missense Variant in a Cat with L-2-Hydroxyglutaric Aciduria

Genes ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 682
Author(s):  
Matthias Christen ◽  
Nils Janzen ◽  
Anne Fraser ◽  
Adrian C. Sewell ◽  
Vidhya Jagannathan ◽  
...  
Keyword(s):  
Current Knowledge ◽  
Genetic Defect ◽  
Clinical Signs ◽  
Missense Variant ◽  
Microcytic Anemia ◽  
Abnormal Behavior ◽  
Functional Candidate Gene ◽  
History Of ◽  
The Brain ◽  
Hydroxyglutaric Acid

A 7-month-old, spayed female, domestic longhair cat with L-2-hydroxyglutaric aciduria (L-2-HGA) was investigated. The aim of this study was to investigate the clinical signs, metabolic changes and underlying genetic defect. The owner of the cat reported a 4-month history of multiple paroxysmal seizure-like episodes, characterized by running around the house, often in circles, with abnormal behavior, bumping into obstacles, salivating and often urinating. The episodes were followed by a period of disorientation and inappetence. Neurological examination revealed an absent bilateral menace response. Routine blood work revealed mild microcytic anemia but biochemistry, ammonia, lactate and pre- and post-prandial bile acids were unremarkable. MRI of the brain identified multifocal, bilaterally symmetrical and T2-weighted hyperintensities within the prosencephalon, mesencephalon and metencephalon, primarily affecting the grey matter. Urinary organic acids identified highly increased levels of L-2-hydroxyglutaric acid. The cat was treated with the anticonvulsants levetiracetam and phenobarbitone and has been seizure-free for 16 months. We sequenced the genome of the affected cat and compared the data to 48 control genomes. L2HGDH, coding for L-2-hydroxyglutarate dehydrogenase, was investigated as the top functional candidate gene. This search revealed a single private protein-changing variant in the affected cat. The identified homozygous variant, XM_023255678.1:c.1301A>G, is predicted to result in an amino acid change in the L2HGDH protein, XP_023111446.1:p.His434Arg. The available clinical and biochemical data together with current knowledge about L2HGDH variants and their functional impact in humans and dogs allow us to classify the p.His434Arg variant as a causative variant for the observed neurological signs in this cat.

scholarly journals Molecular evolutionary analysis of human primary microcephaly genes

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Nashaiman Pervaiz ◽  
Hongen Kang ◽  
Yiming Bao ◽  
Amir Ali Abbasi
Keyword(s):  
Evolutionary History ◽  
Genetic Basis ◽  
Brain Size ◽  
Primate Species ◽  
Evolutionary Analysis ◽  
Australopithecus Afarensis ◽  
Primary Microcephaly ◽  
Modern Humans ◽  
History Of ◽  
The Brain

Abstract Background There has been a rapid increase in the brain size relative to body size during mammalian evolutionary history. In particular, the enlarged and globular brain is the most distinctive anatomical feature of modern humans that set us apart from other extinct and extant primate species. Genetic basis of large brain size in modern humans has largely remained enigmatic. Genes associated with the pathological reduction of brain size (primary microcephaly-MCPH) have the characteristics and functions to be considered ideal candidates to unravel the genetic basis of evolutionary enlargement of human brain size. For instance, the brain size of microcephaly patients is similar to the brain size of Pan troglodyte and the very early hominids like the Sahelanthropus tchadensis and Australopithecus afarensis. Results The present study investigates the molecular evolutionary history of subset of autosomal recessive primary microcephaly (MCPH) genes; CEP135, ZNF335, PHC1, SASS6, CDK6, MFSD2A, CIT, and KIF14 across 48 mammalian species. Codon based substitutions site analysis indicated that ZNF335, SASS6, CIT, and KIF14 have experienced positive selection in eutherian evolutionary history. Estimation of divergent selection pressure revealed that almost all of the MCPH genes analyzed in the present study have maintained their functions throughout the history of placental mammals. Contrary to our expectations, human-specific adoptive evolution was not detected for any of the MCPH genes analyzed in the present study. Conclusion Based on these data it can be inferred that protein-coding sequence of MCPH genes might not be the sole determinant of increase in relative brain size during primate evolutionary history.

2005 Verriest Medal awarded to Professor John D. Mollon

2006 ◽  
Vol 23 (3-4) ◽  
pp. ii-ii
Keyword(s):  
Color Vision ◽  
Full Spectrum ◽  
Visual Neuroscience ◽  
Evolutionary Origins ◽  
University Of Cambridge ◽  
Color Vision Tests ◽  
Spectral Coding ◽  
History Of ◽  
The University

The International Colour Vision Society awarded the 2005 Verriest Medal to John D. Mollon, Professor of Visual Neuroscience at the University of Cambridge, UK. This award is bestowed by the Society to honor long-term contributions to the field of color vision. If the field of color vision were itself a rainbow, then Professor Mollon's contributions cover nearly its full spectrum, including the isolation and elucidation of basic chromatic coding mechanisms and the constraints that they impose on human (and more generally primate) visual performance, the genetic basis of spectral coding mechanisms, the ecological influences on and evolutionary origins of chromatic discrimination. He has been instrumental in the design of several new color vision tests and has extensively exploited abnormal models, both congenital and acquired, to further our understanding of normal mechanisms. He is especially appreciated for his keen and profound sense of the history of science, in particular with respect to the field of color vision. He has been a member of the society for over 25 years and is currently serving on its board of directors. He organized the 2001 ICVS meeting in Cambridge, celebrating the bicentennial of Thomas Young's lecture on color vision.

Streptococcus pluranimalium meningoencephalitis in a horse

2021 ◽  
pp. 104063872110234
Author(s):  
Dah-Jiun Fu ◽  
Akhilesh Ramachandran ◽  
Craig Miller
Keyword(s):  
Ribosomal Rna ◽  
Cross Sections ◽  
Nucleotide Sequencing ◽  
Formalin Fixed Paraffin ◽  
Quarter Horse ◽  
Formalin Fixed Paraffin Embedded ◽  
History Of ◽  
The Brain ◽  
Gram Positive Cocci ◽  
Formalin Fixed

A 3-y-old, female Quarter Horse with a history of acute neurologic signs was found dead and was submitted for postmortem examination. Areas of petechial and ecchymotic hemorrhage were present on cross-sections of the cerebrum, cerebellum, and brainstem. Histologic examination of the brain revealed severe, purulent meningoencephalitis and vasculitis with a myriad of intralesional gram-positive cocci. Streptococcus pluranimalium was identified from formalin-fixed, paraffin-embedded tissue obtained from sites with active lesions by PCR and nucleotide sequencing of bacterial 16S ribosomal RNA. S. pluranimalium should be considered as a cause of meningoencephalitis in a horse.

scholarly journals A Rare Case of Spontaneous Arachnoid Cyst Rupture Presenting as Right Hemiplegia and Expressive Aphasia in a Pediatric Patient

Children ◽  
2021 ◽  
Vol 8 (2) ◽  
pp. 78
Author(s):  
Anne Bryden ◽  
Natalie Majors ◽  
Vinay Puri ◽  
Thomas Moriarty
Keyword(s):  
Cognitive Processing ◽  
Arachnoid Cyst ◽  
Memory Loss ◽  
Acute Onset ◽  
Word Finding ◽  
Outpatient Visits ◽  
The Family ◽  
History Of ◽  
Cyst Rupture ◽  
The Brain

This study examines an 11-year-old boy with a known history of a large previously asymptomatic arachnoid cyst (AC) presenting with acute onset of right facial droop, hemiplegia, and expressive aphasia. Shortly after arrival to the emergency department, the patient exhibited complete resolution of right-sided hemiplegia but developed headache and had persistent word-finding difficulties. Prior to symptom onset while in class at school, there was an absence of reported jerking movements, headache, photophobia, fever, or trauma. At the time of neurology consultation, the physical exam showed mildly delayed cognitive processing but was otherwise unremarkable. The patient underwent MRI scanning of the brain, which revealed left convexity subdural hematohygroma and perirolandic cortex edema resulting from ruptured left frontoparietal AC. He was evaluated by neurosurgery and managed expectantly. He recovered uneventfully and was discharged two days after presentation remaining asymptomatic on subsequent outpatient visits. The family express concerns regarding increased anxiety and mild memory loss since hospitalization.

scholarly journals Further twists in gastropod shell evolution

2008 ◽  
Vol 4 (2) ◽  
pp. 179-182 ◽  
Author(s):  
Reuben Clements ◽  
Thor-Seng Liew ◽  
Jaap Jan Vermeulen ◽  
Menno Schilthuizen
Keyword(s):  
Evolutionary Biology ◽  
Logarithmic Spiral ◽  
Spiral Growth ◽  
Evolutionary Perspective ◽  
Gastropod Shell ◽  
Form And Function ◽  
Evolutionary Origins ◽  
Taxonomic Groups ◽  
And Function ◽  
Shell Coiling

The manner in which a gastropod shell coils has long intrigued laypersons and scientists alike. In evolutionary biology, gastropod shells are among the best-studied palaeontological and neontological objects. A gastropod shell generally exhibits logarithmic spiral growth, right-handedness and coils tightly around a single axis. Atypical shell-coiling patterns (e.g. sinistroid growth, uncoiled whorls and multiple coiling axes), however, continue to be uncovered in nature. Here, we report another coiling strategy that is not only puzzling from an evolutionary perspective, but also hitherto unknown among shelled gastropods. The terrestrial gastropod Opisthostoma vermiculum sp. nov. generates a shell with: (i) four discernable coiling axes, (ii) body whorls that thrice detach and twice reattach to preceding whorls without any reference support, and (iii) detached whorls that coil around three secondary axes in addition to their primary teleoconch axis. As the coiling strategies of individuals were found to be generally consistent throughout, this species appears to possess an unorthodox but rigorously defined set of developmental instructions. Although the evolutionary origins of O. vermiculum and its shell's functional significance can be elucidated only once fossil intermediates and live individuals are found, its bewildering morphology suggests that we still lack an understanding of relationships between form and function in certain taxonomic groups.

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