Size change in development and evolution

1968 ◽  
Vol 42 (S2) ◽  
pp. 1-15 ◽  
Author(s):  
John Tyler Bonner
Keyword(s):  
Natural Selection ◽  
Maximum Size ◽  
Size Increase ◽  
Size Change ◽  
Genetic Changes ◽  
Organic Evolution ◽  
Fluctuating Environments ◽  
Development And Evolution

Phylogeny is a succession of ontogenies, and the two have been compared by considering them in terms of rates of size change. In development, the larger the organism, the slower its rate of size increase. In evolution, the rates of size change can be put into three distinct categories: fast, medium, and slow. The fast changes occur over short periods of time (1–10 thousand years) and are as likely to show size decrease as increase. The medium changes occur over longer time spans (5–20 million years) and are predominantly or entirely instances of size increase. The slow changes occur over the entire span of organic evolution and represent the maximum size attained in various phyla, which again show an over-all increase.For ontogeny, a decrease in rate of size change is correlated with an increase in complexity, an increase in the number of gene actions. For evolution, it is correlated with an increase in the number of genetic changes required of the genome by natural selection in fluctuating environments.

Between Evolution and History: Biology, Culture, and the Myth of Human Origins

2002 ◽  
Author(s):  
Tim Ingold
Keyword(s):  
Natural Selection ◽  
Cultural Change ◽  
Life Histories ◽  
Relational Model ◽  
Human Origins ◽  
Organic Evolution ◽  
Organic World ◽  
Total Process ◽  
Development And Evolution ◽  
Biological Organisms

This chapter explains how the phenomena of both organic evolution and cultural change can be accommodated within a single explanatory paradigm. It first argues that a model of variation under selection cannot fully grasp the generative dynamics of cultural change, and instead calls for an emphasis on the activities that give rise to artefacts, rather than on the final forms of such artefacts. It then discusses history as but one aspect of a total process of evolution that embraces the entire organic world; how biological organisms and cultural artefacts condition the development of other entities or beings to which they relate; and genotypes and phenotypes in relation to natural selection. It also describes the genealogical model in comparison with the relational model, with particular reference to their application to understanding the kinship of both human and nonhuman beings, and how the relational model can be applied not only to persons but also to the development and evolution of organisms. The chapter concludes by discussing the life-histories of artefacts in terms of replication and reproduction.

scholarly journals The Temporal Dynamics of Background Selection in Nonequilibrium Populations

Genetics ◽  
2020 ◽  
Vol 214 (4) ◽  
pp. 1019-1030 ◽  
Author(s):  
Raul Torres ◽  
Markus G. Stetter ◽  
Ryan D. Hernandez ◽  
Jeffrey Ross-Ibarra
Keyword(s):  
Natural Selection ◽  
Temporal Dynamics ◽  
Direct Action ◽  
Demographic History ◽  
Empirical Studies ◽  
Natural Populations ◽  
Background Selection ◽  
Size Change ◽  
Demographic Models ◽  
Classical Models

Neutral genetic diversity across the genome is determined by the complex interplay of mutation, demographic history, and natural selection. While the direct action of natural selection is limited to functional loci across the genome, its impact can have effects on nearby neutral loci due to genetic linkage. These effects of selection at linked sites, referred to as genetic hitchhiking and background selection (BGS), are pervasive across natural populations. However, only recently has there been a focus on the joint consequences of demography and selection at linked sites, and some empirical studies have come to apparently contradictory conclusions as to their combined effects. To understand the relationship between demography and selection at linked sites, we conducted an extensive forward simulation study of BGS under a range of demographic models. We found that the relative levels of diversity in BGS and neutral regions vary over time and that the initial dynamics after a population size change are often in the opposite direction of the long-term expected trajectory. Our detailed observations of the temporal dynamics of neutral diversity in the context of selection at linked sites in nonequilibrium populations provide new intuition about why patterns of diversity under BGS vary through time in natural populations and help reconcile previously contradictory observations. Most notably, our results highlight that classical models of BGS are poorly suited for predicting diversity in nonequilibrium populations.

scholarly journals Nature v Natural Selection An Essay on Organic Evolution

Nature ◽  
1896 ◽  
Vol 53 (1374) ◽  
pp. 386-387
Author(s):  
E. B. P.
Keyword(s):  
Natural Selection ◽  
Organic Evolution

scholarly journals Overcoming maladaptive plasticity through plastic compensation

2013 ◽  
Vol 59 (4) ◽  
pp. 526-536 ◽  
Author(s):  
Matthew R.J. Morris ◽  
Sean M. Rogers
Keyword(s):  
Phenotypic Plasticity ◽  
Environmental Heterogeneity ◽  
Adaptive Plasticity ◽  
Genetic Changes ◽  
Phenotypic Similarity ◽  
Fluctuating Environments ◽  
Maladaptive Plasticity ◽  
Adaptive Phenotypic Plasticity ◽  
Genetic Compensation ◽  
Key Terms

Abstract Most species evolve within fluctuating environments, and have developed adaptations to meet the challenges posed by environmental heterogeneity. One such adaptation is phenotypic plasticity, or the ability of a single genotype to produce multiple environmentally-induced phenotypes. Yet, not all plasticity is adaptive. Despite the renewed interest in adaptive phenotypic plasticity and its consequences for evolution, much less is known about maladaptive plasticity. However, maladaptive plasticity is likely an important driver of phenotypic similarity among populations living in different environments. This paper traces four strategies for overcoming maladaptive plasticity that result in phenotypic similarity, two of which involve genetic changes (standing genetic variation, genetic compensation) and two of which do not (standing epigenetic variation, plastic compensation). Plastic compensation is defined as adaptive plasticity overcoming maladaptive plasticity. In particular, plastic compensation may increase the likelihood of genetic compensation by facilitating population persistence. We provide key terms to disentangle these aspects of phenotypic plasticity and introduce examples to reinforce the potential importance of plastic compensation for understanding evolutionary change.

scholarly journals Nature versus Natural Selection: an Essay on Organic Evolution.

1896 ◽  
Vol 5 (4) ◽  
pp. 437
Author(s):  
F. C. S. S. ◽  
Charles Clement Coe
Keyword(s):  
Natural Selection ◽  
Organic Evolution

scholarly journals Empirical evidence for epigenetic inheritance driving evolutionary adaptation

2021 ◽  
Vol 376 (1826) ◽  
Author(s):  
Dragan Stajic ◽  
Lars E. T. Jansen
Keyword(s):  
Gene Expression ◽  
Epigenetic Inheritance ◽  
Potential Contribution ◽  
Evolutionary Adaptation ◽  
Genetic Changes ◽  
Control Of Gene Expression ◽  
Naturally Occurring ◽  
Fluctuating Environments ◽  
Cellular Machinery ◽  
Methylation Patterns

The cellular machinery that regulates gene expression can be self-propagated across cell division cycles and even generations. This renders gene expression states and their associated phenotypes heritable, independently of genetic changes. These phenotypic states, in turn, can be subject to selection and may influence evolutionary adaptation. In this review, we will discuss the molecular basis of epigenetic inheritance, the extent of its transmission and mechanisms of evolutionary adaptation. The current work shows that heritable gene expression can facilitate the process of adaptation through the increase of survival in a novel environment and by enlarging the size of beneficial mutational targets. Moreover, epigenetic control of gene expression enables stochastic switching between different phenotypes in populations that can potentially facilitate adaptation in rapidly fluctuating environments. Ecological studies of the variation of epigenetic markers (e.g. DNA methylation patterns) in wild populations show a potential contribution of this mode of inheritance to local adaptation in nature. However, the extent of the adaptive contribution of the naturally occurring variation in epi-alleles compared to genetic variation remains unclear.This article is part of the theme issue ‘How does epigenetics influence the course of evolution?’

Phanerozoic trends in brachiopod body size from synoptic data

Paleobiology ◽  
2015 ◽  
Vol 41 (3) ◽  
pp. 491-501 ◽  
Author(s):  
Zixiang Zhang ◽  
Michael Augustin ◽  
Jonathan L. Payne
Keyword(s):  
Body Size ◽  
Model Comparison ◽  
Size Increase ◽  
Data Sets ◽  
Size Change ◽  
Invertebrate Paleontology ◽  
History Of ◽  
Global Coverage ◽  
Stratigraphic Ranges ◽  
Permian Mass Extinction

AbstractBody size is one of the most studied phenotypic attributes because it is biologically important and easily measured. Despite a long history of study, however, the pattern of body-size change in diverse higher taxa over the Phanerozoic remains largely unknown because few relevant data sets span more than a single geological period or provide comprehensive, global coverage. In this study, we measured representative specimens of 3414 brachiopod genera illustrated in the Treatise on Invertebrate Paleontology. We applied these size data to stage-resolved stratigraphic ranges from the Treatise and the Paleobiology Database to develop a Phanerozoic record of trends in brachiopod size. Using a model comparison approach, we find that temporal variation in brachiopod size exhibits two distinct modes—a Paleozoic mode of size increase and a post-Paleozoic mode indistinguishable from a random walk. This transition reflects a change in the identities of the most diverse brachiopod orders rather than a shift in mode within any given order. Paleozoic size increase reflects a small, persistent bias toward the origination of new genera larger than those surviving from the previous stage and is identifiable as a statistically supported trend in three orders representing both Class Strophomenata (Order Productida) and Class Rhynchonellata (orders Atrypida and Spiriferida). Extinction exhibits no consistent bias with respect to size. The shift in evolutionary mode across the end-Permian mass extinction adds to long-standing evidence from studies of diversity and abundance that this biotic catastrophe suddenly and permanently altered the evolutionary history of what was, until that time, the most diverse animal phylum on Earth.

Nutrition and Reproductive Ecology

2018 ◽  
pp. 49-66
Author(s):  
Julie J. Lesnik
Keyword(s):  
Body Size ◽  
Natural Selection ◽  
Division Of Labor ◽  
Resource Acquisition ◽  
Child Rearing ◽  
Size Increase ◽  
Human Diet ◽  
Sexual Division ◽  
Sexual Division Of Labor ◽  
Nutritional Needs

Chapter 4 reviews the interplay between nutrition and natural selection. Much of the discussion of evolution of the human diet revolves around energetic requirements because the increased demand is easy to identify as brain and body size increase over our lineage. However, it is important to be reminded that nutrients have other roles besides yielding energy, primarily regulatory and structural. These latter functions are especially important from the viewpoint of female pregnancy and child rearing. This incongruence of reproductive demands between the sexes lends to the discussion of the evolution of sexual division of labor in human societies, suggesting that some of the differences in resource acquisition may be related to different nutritional needs.

Darwin’s Impact on the Medical Sciences

2019 ◽  
pp. 171-186
Author(s):  
Fabio Zampieri
Keyword(s):  
Natural Selection ◽  
Charles Darwin ◽  
Point Of View ◽  
Medical Sciences ◽  
Darwinian Revolution ◽  
Theory Of Evolution ◽  
Organic Evolution ◽  
Medical Issues ◽  
Nineteenth Century Medicine ◽  
The Impact

In early nineteenth century medicine, the concepts of organic evolution and natural selection emerged in different contexts, partly anticipating Darwinian revolution. In particular, the anatomical concept of disease favored the perception that men and animals were very similar from a morphological, physiological and pathological point of view, and that this could indicate a certain degree of kinship between them. The debate around human races and human pathological heredity saw first formulations of the principle of natural selection, even if without a full appraisal of its evolutionary implications. Charles Darwin took many inspirations from these medical theories. The impact of the theory of evolution formulated by him in 1859 was only apparently slight in medicine. It is even possible to support that evolutionary concepts contributed in a significant way to the most important medical issues, debates and new discipline in the period between 1880 and 1940.

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