Alfred Russel Wallace

2014 ◽  
Author(s):  
Martin Fichman
Keyword(s):  
Natural Selection ◽  
Evolutionary Biology ◽  
Amazon Basin ◽  
Evolutionary Process ◽  
Physical Geography ◽  
Unpublished Manuscript ◽  
Scientific Legacy ◽  
Alfred Russel Wallace ◽  
Biogeographical Regions ◽  
The 19Th Century

Alfred Russel Wallace (b. 1823–d. 1913) was one of the most brilliant theoretical and field biologists of the 19th century. He was a meticulous field observer, a prolific generator of ideas on a broad spectrum of issues ranging from evolutionary biology to social and political concerns, and a theoretician whose work laid some of the main foundations for the scientific study of biogeography and evolution. Wallace undertook two tropical journeys that were to transform his life and the emerging science of evolutionary biology: a four-year exploration of the Amazon basin of South America (1848–1852) and an eight-year exploration of the Malay Archipelago (1854–1862), including the islands of Java, Borneo, Celebes, New Guinea, and Bali. Wallace later generalized his findings from Southeast Asia to elaborate a global paradigm for identifying the earth’s fundamental biogeographical regions in his magisterial Geographical Distribution of Animals (1876). It was, of course, Wallace’s elucidation of the mechanism of evolution—in his 1858 “On the Tendency of Varieties to Depart Indefinitely from the Original Type”—that constitutes his greatest scientific legacy from his Malay travels. A copy of Wallace’s essay, along with extracts from an unpublished manuscript on natural selection written by Darwin in 1844, were presented together at the historic meeting of the Linnean Society (London) on 1 July 1858. This meeting—a year prior to the publication of Darwin’s On the origin of species (1859)—ensured that both Wallace and Darwin received recognition and joint priority for their momentous discovery of natural selection. Wallace spent the remainder of his long life in elucidating the implications of evolutionary theory for biogeography, sexual selection, the phenomenon of organic mimicry taxonomy, physical geography and geology, and anthropology. Although he remained an ardent selectionist in his overall analysis of evolutionary processes, Wallace considered natural selection inadequate to account completely for the origin and development of certain human characteristics, notably, consciousness and the moral sense. He insisted that certain aspects of theism and of political and social ideologies, including socialism, spiritualism, and anti-vaccinationism, were not merely compatible with the evolutionary process but essential for comprehending the full significance of human evolution. The issues Wallace confronted continue to resonate in contemporary debates on the scope, mechanism, and, ultimately, significance of evolution in both scientific and cultural domains. In the past two decades there has been a resurgence of interest in Wallace, and this article provides a scholarly guide through the thicket of materials now emerging on his life and achievements.

Units and levels of selection

2018 ◽  
Author(s):  
Samir Okasha
Keyword(s):  
Natural Selection ◽  
Kin Selection ◽  
Evolutionary Biology ◽  
Evolutionary Process ◽  
Levels Of Selection ◽  
Evolutionary Transitions ◽  
Individual Organism ◽  
Selection Processes ◽  
Hierarchical Levels ◽  
The Individual

In a standard Darwinian explanation, natural selection takes place at the level of the individual organism, i.e. some organisms enjoy a survival or reproduction advantage over others, which results in evolutionary change. In principle however, natural selection could operate at other hierarchical levels too, above and below that of the organism, for example the level of genes, cells, groups, colonies or even whole species. This possibility gives rise to the ‘levels of selection’ question in evolutionary biology. Group and colony-level selection have been proposed, originally by Darwin, as a means by which altruism can evolve. (In biology, ‘altruism’ refers to behaviour which entails a fitness cost to the individual so behaving, but benefits others.) Though this idea is still alive today, many theorists regard kin selection as a superior explanation for the existence of altruism. Kin selection arises from the fact that relatives share genes, so if an organism behaves altruistically towards its relatives, there is a greater than random chance that the beneficiary of the altruistic action will itself be an altruist. Kin selection is closely bound up with the ‘gene’s eye view’ of evolution, which holds that genes, not organisms, are the true beneficiaries of the evolutionary process. The gene’s eye approach to evolution, though heuristically valuable, does not in itself resolve the levels of selection question, because selection processes that occur at many hierarchical levels can all be seen from a gene’s eye viewpoint. In recent years, the levels of selection discussion has been re-invigorated, and subtly transformed, by the important new work on the ‘major evolutionary transitions’. These transitions occur when a number of free-living biological units, originally capable of surviving and reproducing alone, become integrated into a larger whole, giving rise to a new biological unit at a higher level of organization. Evolutionary transitions are intimately bound up with the levels of selection issue, because during a transition the potential exists for selection to operate simultaneously at two different hierarchical levels.

An Evolutionary Approach to Synthetic Biology: Zen and the Art of Creating Life

1993 ◽  
Vol 1 (1_2) ◽  
pp. 179-209 ◽  
Author(s):  
Thomas S. Ray
Keyword(s):  
Natural Selection ◽  
Synthetic Biology ◽  
Evolutionary Biology ◽  
Evolutionary Process ◽  
Life Forms ◽  
Evolutionary Approach ◽  
Artificial Medium ◽  
Natural Form ◽  
Evolution By Natural Selection ◽  
Physical Laws

Our concepts of biology, evolution, and complexity are constrained by having observed only a single instance of life, life on earth. A truly comparative biology is needed to extend these concepts. Because we cannot observe life on other planets, we are left with the alternative of creating Artificial Life forms on earth. I will discuss the approach of inoculating evolution by natural selection into the medium of the digital computer. This is not a physical/chemical medium; it is a logical/informational medium. Thus, these new instances of evolution are not subject to the same physical laws as organic evolution (e.g., the laws of thermodynamics) and exist in what amounts to another universe, governed by the “physical laws” of the logic of the computer. This exercise gives us a broader perspective on what evolution is and what it does. An evolutionary approach to synthetic biology consists of inoculating the process of evolution by natural selection into an artificial medium. Evolution is then allowed to find the natural forms of living organisms in the artificial medium. These are not models of life, but independent instances of life. This essay is intended to communicate a way of thinking about synthetic biology that leads to a particular approach: to understand and respect the natural form of the artificial medium, to facilitate the process of evolution in generating forms that are adapted to the medium, and to let evolution find forms and processes that naturally exploit the possibilities inherent in the medium. Examples are cited of synthetic biology embedded in the computational medium, where in addition to being an exercise in experimental comparative evolutionary biology, it is also a possible means of harnessing the evolutionary process for the production of complex computer software.

Evolution: A Very Short Introduction

2017 ◽  
Author(s):  
Brian Charlesworth ◽  
Deborah Charlesworth
Keyword(s):  
New Species ◽  
Natural Selection ◽  
Evolutionary Biology ◽  
Charles Darwin ◽  
Short Introduction ◽  
Alfred Russel Wallace ◽  
Wide Range ◽  
Living Species ◽  
Evolution By Natural Selection ◽  
Special Creation

Less than 150 years ago, the view that living species were the result of special creation by God was still dominant. The recognition by Charles Darwin and Alfred Russel Wallace of the mechanism of evolution by natural selection has completely transformed our understanding of the living world, including our own origins. Evolution: A Very Short Introduction provides a summary of the process of evolution by natural selection, highlighting the wide range of evidence, and explains how natural selection gives rise to adaptations and eventually, over many generations, to new species. It introduces the central concepts of the field of evolutionary biology and discusses some of the remaining questions regarding evolutionary processes.

Contingency and determinism in evolution: Replaying life’s tape

Science ◽  
2018 ◽  
Vol 362 (6415) ◽  
pp. eaam5979 ◽  
Author(s):  
Zachary D. Blount ◽  
Richard E. Lenski ◽  
Jonathan B. Losos
Keyword(s):  
Natural Selection ◽  
Evolutionary Biology ◽  
Empirical Studies ◽  
Evolutionary Process ◽  
Random Mutation ◽  
Ongoing Research ◽  
Adaptive Landscapes ◽  
Historical Processes ◽  
History Of ◽  
Evolutionary Paths

Historical processes display some degree of “contingency,” meaning their outcomes are sensitive to seemingly inconsequential events that can fundamentally change the future. Contingency is what makes historical outcomes unpredictable. Unlike many other natural phenomena, evolution is a historical process. Evolutionary change is often driven by the deterministic force of natural selection, but natural selection works upon variation that arises unpredictably through time by random mutation, and even beneficial mutations can be lost by chance through genetic drift. Moreover, evolution has taken place within a planetary environment with a particular history of its own. This tension between determinism and contingency makes evolutionary biology a kind of hybrid between science and history. While philosophers of science examine the nuances of contingency, biologists have performed many empirical studies of evolutionary repeatability and contingency. Here, we review the experimental and comparative evidence from these studies. Replicate populations in evolutionary “replay” experiments often show parallel changes, especially in overall performance, although idiosyncratic outcomes show that the particulars of a lineage’s history can affect which of several evolutionary paths is taken. Comparative biologists have found many notable examples of convergent adaptation to similar conditions, but quantification of how frequently such convergence occurs is difficult. On balance, the evidence indicates that evolution tends to be surprisingly repeatable among closely related lineages, but disparate outcomes become more likely as the footprint of history grows deeper. Ongoing research on the structure of adaptive landscapes is providing additional insight into the interplay of fate and chance in the evolutionary process.

An integrative redescription of Hypsibius dujardini (Doyère, 1840), the nominal taxon for Hypsibioidea (Tardigrada: Eutardigrada)

Zootaxa ◽  
2018 ◽  
Vol 4415 (1) ◽  
pp. 45 ◽  
Author(s):  
PIOTR GĄSIOREK ◽  
DANIEL STEC ◽  
WITOLD MOREK ◽  
ŁUKASZ MICHALCZYK
Keyword(s):  
Dna Sequences ◽  
Evolutionary Biology ◽  
Model Organism ◽  
Laboratory Strain ◽  
Sensu Stricto ◽  
Nominal Species ◽  
28S Rrna ◽  
The Family ◽  
The 19Th Century ◽  
Hypsibius Dujardini

A laboratory strain identified as “Hypsibius dujardini” is one of the best studied tardigrade strains: it is widely used as a model organism in a variety of research projects, ranging from developmental and evolutionary biology through physiology and anatomy to astrobiology. Hypsibius dujardini, originally described from the Île-de-France by Doyère in the first half of the 19th century, is now the nominal species for the superfamily Hypsibioidea. The species was traditionally considered cosmopolitan despite the fact that insufficient, old and sometimes contradictory descriptions and records prevented adequate delineations of similar Hypsibius species. As a consequence, H. dujardini appeared to occur globally, from Norway to Samoa. In this paper, we provide the first integrated taxonomic redescription of H. dujardini. In addition to classic imaging by light microscopy and a comprehensive morphometric dataset, we present scanning electron photomicrographs, and DNA sequences for three nuclear markers (18S rRNA, 28S rRNA, ITS-2) and one mitochondrial marker (COI) that are characterised by various mutation rates. The results of our study reveal that a commercially available strain that is maintained in many laboratories throughout the world, and assumed to represent H. dujardini sensu stricto, represents, in fact, a new species: H. exemplaris sp. nov. Redescribing the nominal taxon for Hypsibiidae, we also redefine the family and amend the definitions of the subfamily Hypsibiinae and the genus Hypsibius. Moreover, we transfer H. arcticus (Murray, 1907) and Hypsibius conifer Mihelčič, 1938 to the genus Ramazzottius since the species exhibit claws and eggs of the Ramazzottius type. Finally, we designate H. fuhrmanni as subjectively invalid because the extremely poor description precludes identifying neotype material. 

scholarly journals Genome size correlates with reproductive fitness in seed beetles

2015 ◽  
Vol 282 (1815) ◽  
pp. 20151421 ◽  
Author(s):  
Göran Arnqvist ◽  
Ahmed Sayadi ◽  
Elina Immonen ◽  
Cosima Hotzy ◽  
Daniel Rankin ◽  
...  
Keyword(s):  
Life History ◽  
Natural Selection ◽  
Genome Size ◽  
Evolutionary Biology ◽  
Large Scale ◽  
Life History Traits ◽  
Single Species ◽  
Reproductive Fitness ◽  
Correlated Evolution ◽  
Seed Beetles

The ultimate cause of genome size (GS) evolution in eukaryotes remains a major and unresolved puzzle in evolutionary biology. Large-scale comparative studies have failed to find consistent correlations between GS and organismal properties, resulting in the ‘ C -value paradox’. Current hypotheses for the evolution of GS are based either on the balance between mutational events and drift or on natural selection acting upon standing genetic variation in GS. It is, however, currently very difficult to evaluate the role of selection because within-species studies that relate variation in life-history traits to variation in GS are very rare. Here, we report phylogenetic comparative analyses of GS evolution in seed beetles at two distinct taxonomic scales, which combines replicated estimation of GS with experimental assays of life-history traits and reproductive fitness. GS showed rapid and bidirectional evolution across species, but did not show correlated evolution with any of several indices of the relative importance of genetic drift. Within a single species, GS varied by 4–5% across populations and showed positive correlated evolution with independent estimates of male and female reproductive fitness. Collectively, the phylogenetic pattern of GS diversification across and within species in conjunction with the pattern of correlated evolution between GS and fitness provide novel support for the tenet that natural selection plays a key role in shaping GS evolution.

scholarly journals Evolutionary biology today and the call for an extended synthesis

2017 ◽  
Vol 7 (5) ◽  
pp. 20160145 ◽  
Author(s):  
Douglas J. Futuyma
Keyword(s):  
Natural Selection ◽  
Evolutionary Theory ◽  
Evolutionary Biology ◽  
Epigenetic Inheritance ◽  
Reaction Norm ◽  
Evolutionary Synthesis ◽  
Historical Background ◽  
Extended Evolutionary Synthesis ◽  
Extended Synthesis ◽  
Proximate Causation

Evolutionary theory has been extended almost continually since the evolutionary synthesis (ES), but except for the much greater importance afforded genetic drift, the principal tenets of the ES have been strongly supported. Adaptations are attributable to the sorting of genetic variation by natural selection, which remains the only known cause of increase in fitness. Mutations are not adaptively directed, but as principal authors of the ES recognized, the material (structural) bases of biochemistry and development affect the variety of phenotypic variations that arise by mutation and recombination. Against this historical background, I analyse major propositions in the movement for an ‘extended evolutionary synthesis’. ‘Niche construction' is a new label for a wide variety of well-known phenomena, many of which have been extensively studied, but (as with every topic in evolutionary biology) some aspects may have been understudied. There is no reason to consider it a neglected ‘process’ of evolution. The proposition that phenotypic plasticity may engender new adaptive phenotypes that are later genetically assimilated or accommodated is theoretically plausible; it may be most likely when the new phenotype is not truly novel, but is instead a slight extension of a reaction norm already shaped by natural selection in similar environments. However, evolution in new environments often compensates for maladaptive plastic phenotypic responses. The union of population genetic theory with mechanistic understanding of developmental processes enables more complete understanding by joining ultimate and proximate causation; but the latter does not replace or invalidate the former. Newly discovered molecular phenomena have been easily accommodated in the past by elaborating orthodox evolutionary theory, and it appears that the same holds today for phenomena such as epigenetic inheritance. In several of these areas, empirical evidence is needed to evaluate enthusiastic speculation. Evolutionary theory will continue to be extended, but there is no sign that it requires emendation.

scholarly journals The effect of deforestation on the water cycle in the amazon basin: an attempt reformulate the problem

1985 ◽  
Vol 15 (3-4) ◽  
pp. 307-310 ◽  
Author(s):  
J. R. Gat ◽  
Ε. Matsui ◽  
Ε. Salati
Keyword(s):  
Large Scale ◽  
Amazon Basin ◽  
Water Cycle ◽  
Water Flux ◽  
Atmospheric Stability ◽  
Local Heat ◽  
Physical Geography ◽  
Cloud Formation ◽  
Evaporative Water ◽  
Stability Structure

If widespread deforestation in Amazon results in reduced evaporative water flux, then either a decrease in evaporation is compensated locally by reduced rainfall,or else changed moisture balance expresses itself downwind in the yet undisturbed forest. The question of where rain will occur is crucial. It is suggested that the appearance of clouds and the occurrence of rainout is governed primarily by the interplay of local meteorologic and physical geography parameters with the atmospheric stability structure except for a few well-defined periods when rain is dominated by large scale atmospheric instability. This means that the study of these phenomena (local heat balances,studies on cloud formation mechanism, vertical atmospheric stability, etc.) must be made on the scale of the cloud size, a few tens of kilometers at most.

scholarly journals The evolution of superstitious and superstition-like behaviour

2008 ◽  
Vol 276 (1654) ◽  
pp. 31-37 ◽  
Author(s):  
Kevin R Foster ◽  
Hanna Kokko
Keyword(s):  
Popular Culture ◽  
Natural Selection ◽  
Simple Model ◽  
Correct Response ◽  
Evolutionary Biology ◽  
Adaptive Behaviour ◽  
Multiple Events ◽  
Cause And Effect ◽  
Pascal’S Wager ◽  
Hamilton's Rule

Superstitious behaviours, which arise through the incorrect assignment of cause and effect, receive considerable attention in psychology and popular culture. Perhaps owing to their seeming irrationality, however, they receive little attention in evolutionary biology. Here we develop a simple model to define the condition under which natural selection will favour assigning causality between two events. This leads to an intuitive inequality—akin to an amalgam of Hamilton's rule and Pascal's wager—-that shows that natural selection can favour strategies that lead to frequent errors in assessment as long as the occasional correct response carries a large fitness benefit. It follows that incorrect responses are the most common when the probability that two events are really associated is low to moderate: very strong associations are rarely incorrect, while natural selection will rarely favour making very weak associations. Extending the model to include multiple events identifies conditions under which natural selection can favour associating events that are never causally related. Specifically, limitations on assigning causal probabilities to pairs of events can favour strategies that lump non-causal associations with causal ones. We conclude that behaviours which are, or appear, superstitious are an inevitable feature of adaptive behaviour in all organisms, including ourselves.

scholarly journals The quantum mitochondrion and optimal health

2016 ◽  
Vol 44 (4) ◽  
pp. 1101-1110 ◽  
Author(s):  
Alistair V.W. Nunn ◽  
Geoffrey W. Guy ◽  
Jimmy D. Bell
Keyword(s):  
Natural Selection ◽  
Energy Production ◽  
Healthy Aging ◽  
Evolutionary Process ◽  
Emergent Behaviour ◽  
Whole Process ◽  
Optimal Health ◽  
Response To Stress ◽  
Will Self ◽  
Selection Of

A sufficiently complex set of molecules, if subject to perturbation, will self-organize and show emergent behaviour. If such a system can take on information it will become subject to natural selection. This could explain how self-replicating molecules evolved into life and how intelligence arose. A pivotal step in this evolutionary process was of course the emergence of the eukaryote and the advent of the mitochondrion, which both enhanced energy production per cell and increased the ability to process, store and utilize information. Recent research suggest that from its inception life embraced quantum effects such as ‘tunnelling’ and ‘coherence’ while competition and stressful conditions provided a constant driver for natural selection. We believe that the biphasic adaptive response to stress described by hormesis–a process that captures information to enable adaptability, is central to this whole process. Critically, hormesis could improve mitochondrial quantum efficiency, improving the ATP/ROS ratio, whereas inflammation, which is tightly associated with the aging process, might do the opposite. This all suggests that to achieve optimal health and healthy aging, one has to sufficiently stress the system to ensure peak mitochondrial function, which itself could reflect selection of optimum efficiency at the quantum level.

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