scholarly journals Comparative embryology without a microscope: using genomic approaches to understand the evolution of development

2009 ◽  
Vol 8 (7) ◽  
pp. 65 ◽  
Author(s):  
David A Garfield ◽  
Gregory A Wray
Keyword(s):  
Evolution Of Development ◽  
Comparative Embryology

Toward a Nonidealist Evolutionary Synthesis

2017 ◽  
Author(s):  
Stuart A. Newman
Keyword(s):  
Evolutionary Theory ◽  
Raw Material ◽  
Evolutionary Synthesis ◽  
Living Systems ◽  
Evolution Of Development ◽  
Search Process ◽  
Physical Processes ◽  
Explanatory Framework ◽  
Material Systems ◽  
Modern Physics

The received model of evolution sees all inherited features resulting from deterministic networks of interacting genes, implying that living systems are reducible to information in genetic programs. The model requires these programs and their associated phenotypes to have evolved by an isotropic search process occurring in gradual steps with no preferred morphological outcomes. The alternative is to recognize that clusters and aggregates of cells, the raw material of evolution, constitute middle-scale material systems. This implies the necessity of bringing the modern physics of mesoscale matter into the explanatory framework for the evolution of development. The relevant, often nonlinear, physical processes were mobilized at the inception of the phyla when their signature morphological outcomes first appeared and remain as efficient causes, albeit transformed, in present-day embryos. This physicogenetic perspective reengages with concepts of saltation, orthogenesis, and environment-induced plasticity long excluded from evolutionary theory.

scholarly journals Heterokairy: a significant form of developmental plasticity?

2016 ◽  
Vol 12 (9) ◽  
pp. 20160509 ◽  
Author(s):  
S. D. Rundle ◽  
J. I. Spicer
Keyword(s):  
Research Agenda ◽  
Developmental Plasticity ◽  
Potential Role ◽  
Research Effort ◽  
Adaptive Significance ◽  
Research Interest ◽  
Adaptive Plasticity ◽  
Comparative Embryology ◽  
A Current

There is a current surge of research interest in the potential role of developmental plasticity in adaptation and evolution. Here we make a case that some of this research effort should explore the adaptive significance of heterokairy, a specific type of plasticity that describes environmentally driven, altered timing of development within a species. This emphasis seems warranted given the pervasive occurrence of heterochrony, altered developmental timing between species, in evolution. We briefly review studies investigating heterochrony within an adaptive context across animal taxa, including examples that explore links between heterokairy and heterochrony. We then outline how sequence heterokairy could be included within the research agenda for developmental plasticity. We suggest that the study of heterokairy may be particularly pertinent in (i) determining the importance of non-adaptive plasticity, and (ii) embedding concepts from comparative embryology such as developmental modularity and disassociation within a developmental plasticity framework.

Structure of the insect head as revealed by the EN protein pattern in developing embryos

Development ◽  
1996 ◽  
Vol 122 (11) ◽  
pp. 3419-3432 ◽  
Author(s):  
B.T. Rogers ◽  
T.C. Kaufman
Keyword(s):  
Drosophila Melanogaster ◽  
Pattern Formation ◽  
Protein Pattern ◽  
Related Protein ◽  
Specific Expression ◽  
Tissue Specific Expression ◽  
Single Segment ◽  
Dorsal Ridge ◽  
Insect Embryos ◽  
Comparative Embryology

The structure of the insect head has long been a topic of enjoyable yet endless debate among entomologists. More recently geneticists and molecular biologists trying to better understand the structure of the head of the Dipteran Drosophila melanogaster have joined the discourse extrapolating from what they have learned about Drosophila to insects in general. Here we present the results of an investigation into the structure of the insect head as revealed by the distribution of engrailed related protein (Engrailed) in the insect orders Diptera, Siphonaptera, Orthoptera and Hemiptera. The results of this comparative embryology in conjunction with genetic experiments on Drosophila melanogaster lead us to conclude: (1) The insect head is composed of six Engrailed accumulating segments, four postoral and two preoral. The potential seventh and eighth segments (clypeus or labrum) do not accumulate Engrailed. (2) The structure known as the dorsal ridge is not specific to the Diptera but is homologous to structures found in other insect orders. (3) A part of this structure is a single segment-like entity composed of labial and maxillary segment derivatives which produce the most anterior cuticle capable of taking a dorsal fate. The segments anterior to the maxillary segment produce only ventral structures. (4) As in Drosophila, the process of segmentation of the insect head is fundamentally different from the process of segmentation in the trunk. (5) The pattern of Engrailed accumulation and its presumed role in the specification and development of head segments appears to be highly conserved while its role in other pattern formation events and tissue-specific expression is variable. An overview of the pattern of Engrailed accumulation in developing insect embryos provides a basis for discussion of the generality of the parasegment and the evolution of Engrailed patterns.

EVOLUTION OF DEVELOPMENT OF THE ELECTION PROCESS OF THE REPUBLIC OF KAZAKHSTAN: POLITICAL ANALYSIS

2021 ◽  
Vol 74 (2) ◽  
pp. 133-141
Author(s):  
А.М. Amirzhanova ◽  
◽  
Keyword(s):  
Comparative Analysis ◽  
Evolutionary Development ◽  
Scientific Article ◽  
Evolution Of Development ◽  
Democratic Regime ◽  
Political Analysis ◽  
Election Process ◽  
The Republic ◽  
Legislative Reforms ◽  
Number Of Parties

The article provides a comparative analysis of the evolution features of the formation and development of representational bodies through the institution of elections, which is one of the most important and urgent issues in the context of democratization in modern Kazakhstan. The main purpose of the scientific article is to analyze the elections in the formation of representative authority in Kazakhstan from the standpoint of political science. This is related to the fact that the electoral process in the country is developing in accordance with the democratic regime, undergoing legislative reforms and difficulties in improving. Thus, the article examines the issues of the evolutionary development of elections by the methods of comparative analysis, cross-temporal comparison, and identifies the features of development. Also, the structure of a representative government formed on the basis of elections in independent Kazakhstan, the peculiarities of the participation of the electorate in elections, the proportion of women in the Mazhilis, the number of parties, and the average age were compared. Elections are one of the main indicators in the formation of representative power.

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