Many: The Diversity of Life on Earth by Nicola Davies

2017 ◽  
Vol 71 (3) ◽  
pp. 113-113
Author(s):  
Deborah Stevenson
Megataxa ◽  
2020 ◽  
Vol 1 (1) ◽  
pp. 35-38
Author(s):  
MIGUEL VENCES

Documenting, naming and classifying the diversity of life on Earth provides baseline information on the biosphere, which is crucially important to understand and mitigate the global changes of the Anthropocene. We should meet three main challenges, using new technological developments without throwing the well-tried and successful foundations of Linnaean nomenclature overboard. 1. Fully embrace cybertaxonomy, machine learning and DNA taxonomy to ease, not burden the workflow of taxonomists. 2. Emphasize diagnosis over description, images over words. 3. Understand promises and pitfalls of omics approaches to avoid taxonomic inflation.


Ecology ◽  
2019 ◽  
Author(s):  
Linyi Zhang ◽  
Scott P. Egan

The spectacular diversity of life on earth presents one of the most intriguing questions for biologists: why and how does the variation among organisms arise? One powerful concept that has its origins with Darwin (late 1800s) and was developed in detail during the Modern Synthesis (early to mid-1900s), is “adaptive radiation.” This evolutionary process refers to the rapid diversification of a single lineage into many different species during which different morphological/ecological traits evolve in association with different environments and niches. The central components of adaptive radiation are (1) rapid diversification of multiple species from a single common ancestor and (2) different species exhibit different ecological traits that are adaptive to different niches. While many great individual cases of adaptive radiation have been studied, such as Darwin’s finches, African rift lake cichlids, and Hawaiian silverswords, controversies remain on topics such as the definition of an adaptive radiation, the appropriate approach to test for it, and the ultimate causes of an adaptive radiation. This article provides a general overview of the literature addressing the study of adaptive radiation, including taxa-specific examples and major literature reviews. The article will highlight literature that helps to clarify the concept of adaptive radiation by distinguishing it from other related biological processes. Then the literature on specific approaches to test for adaptive radiation is featured. Next, connections to the literature aiming to understand the proximate and ultimate causes of adaptive radiation are provided, including explicit tests of the role of ecology, as well as an exploration of the source of genetic variation and geographic conditions promoting adaptive radiation. Lastly, we connect to the literature addressing the constraints on adaptive radiations. Overall, this article will address research on the origin of new species and the evolution of ecological differences between them.


Author(s):  
Jorge Moreira ◽  
Fátima Alves ◽  
Ana Mendonça

Contemporary sciences and societies are facing several problems when analyzing the relationship between the natural and social dimensions of the world as reflected in the field of education. A serious effort must be urgently made to identify and tackle environmental problems in order to understand the world in which we live, in ways that are beneficial to present and future life on Earth. In this context, it is fundamental to create a new social order in a way that thinking “out of the box” can emerge with other orders closer to the diversity of life that coexist on the planet. Consequently, the awareness of the complexity and multidimensionality of our world requires the building of new forms of reflexivity and the development of critical thinking, reversing the still predominant characteristics of modern societies such as compartmentalization of knowledge, unhealthy competition, profit-seeking motivations, the exploitation of nature, and excessive individualist and anthropocentric approaches. In this regard, educational institutions play a relevant role in shaping future human actions to be more ethically harmonic (both environmentally and socially) as they are sites of knowledge production and sharing. Hence, it is crucial to rethink the entire educational paradigm and learning system (objectives, curricula, pedagogical strategies, instruments, competencies, school management framework, and even school buildings), because schools often function as “islands,” isolating students from nature, the community, and the “real world,” not preparing them to be well-informed and conscious citizens nor for the challenges that lie ahead. Some theoretical and practical alternatives are needed since schools actually embody the paradoxes and dilemmas of the current societal malaise but have not yet been able to deal with them or to provide adequate effective responses.


1996 ◽  
Vol 351 (1345) ◽  
pp. 1227-1231 ◽  

The great Darwinian truth that underlies our attempts to discover rhyme and reason in the diversity of life on Earth is that natural selection has shaped the form and behaviour of organisms. The search for the evolutionary pathways that lead to the present diversity of life, the study of phylogeny, was among the most powerful forces in the development of biological science in the latter part of the 19th and first half of the 20th century. It provided a fascinating intellectual exercise to draw out putative evolutionary sequences and gave the excuse for quite violent conflicts of interpretation. Comparative morphology was the main (and often the only) source of data for such phylogenetic speculation. It acknowledged that some features, ‘conservative characters’, were more resistant than others to evolutionary pressures and so were more reliable for tracing lineages. To establish phylogenies it became vitally important to identify these ‘conservative’ characters and to distinguish them from features that responded m ore quickly to selective pressures and therefore indicated only recent ancestry.


2017 ◽  
Author(s):  
Ronald D. Smith ◽  
Taliesin J. Kinser ◽  
Gregory D. Conradi Smith ◽  
Joshua R. Puzey

AbstractBackground: Gene duplications are a major source of raw material for evolution and a likely contributor to the diversity of life on earth. Duplicate genes (i.e., homeologs, in the case of a whole genome duplication) may retain their ancestral function, sub- or neofunctionalize, or be lost entirely. A primary way that duplicate genes may evolve new functions is by altering their expression patterns. Comparing the expression patterns of duplicate genes may give clues as to whether any of these evolutionary processes have occurred.Results: We develop a likelihood ratio test for the analysis of the expression ratios of duplicate genes across two conditions (e.g., tissues). We demonstrate an application of this test by comparing homeolog expression patterns of 1,448 homeologous gene pairs using RNA-seq data generated from the leaves and petals of an allotetraploid monkeyflower (Mimulus luteus). We assess the sensitivity of this test to different levels of homeolog expression bias and compare the method to several alternatives.Conclusions: The likelihood ratio test derived here is a direct, transparent, and easily implemented method for detecting changes in homeolog expression bias that outperforms three alternative approaches. While our method was derived with homeolog analysis in mind, this method can be used to analyze changes in the ratio of expression levels between any two genes in any two conditions.


2021 ◽  
Author(s):  
Douglas G. Moore ◽  
Matheo Morales ◽  
Sara I. Walker ◽  
Greer A. Dolby

The process of forming new species is the driving force behind the diversity of life on Earth. Yet, we have not answered the basic question: why are species unevenly distributed across taxonomic groups and geographic settings? This is because we lack the means to directly compare aspects of population (lineage) divergence across unrelated species because taxon-specific effects make comparisons difficult or impossible. Here, we present a new solution to this challenge by identifying the information signature of diverging lineages, calculated using partial information decomposition (PID), under different evolutionary scenarios. We show in silico how the informational decomposition of genetic metrics varies over time since divergence. Calculating PID over 97,200 lattices reveals that the decomposed nodes of Tajima’s D, θW, and π have strong information signatures, while FST was least useful for discriminating among divergence scenarios. The presence or absence of gene flow during divergence was the most detectable signature; mutation rate and effective population size (Ne) were also detectable whereas differences in recombination rate were not. This work demonstrates that PID can reveal evolutionary patterns that are minimally detectable using the raw metrics themselves; it does so by leveraging the architecture of the genome and the partial redundancy of information contained in genetic metrics. Our results demonstrate for the first time how to directly compare characteristics of diverging populations even among distantly related species, providing a foundational tool for understanding the diversity of life across Earth.


2021 ◽  
Author(s):  
Andres A. Del Risco ◽  
Diego A. Chacon ◽  
Lucia Angel ◽  
David A. Garcia

Since the concept of the tree of life was introduced by Darwin about a century and a half ago, a considerable fraction of the scientific community has focused its efforts on its reconstruction, with remarkable progress during the last two decades with the advent of DNA sequences. However, the assemblage of a comprehensive tree of life for its exploration has been a difficult task to achieve due to two main obstacles: i) information is scattered into a plethora of individual sources and ii) practical visualization tools for exceptionally large trees are lacking. To overcome both challenges, we aimed to synthetize a family-level tree of life by compiling over 1400 published phylogenetic studies, ensuring that the source trees represent the best phylogenetic hypotheses to date based on a set of objective criteria. Moreover, we dated the synthetic tree by employing over 550 secondary-calibration points, using publicly available sequences for more than 5000 taxa, and by incorporating age ranges from the fossil record for over 2800 taxa. Additionally, we developed a mobile app (Tree of Life) for smartphones in order to facilitate the visualization and interactive exploration of the resulting tree. Interactive features include an easy exploration by zooming and panning gestures of touch screens, collapsing branches, visualizing specific clades as subtrees, a search engine, a timescale to determine extinction and divergence dates, and quick links to Wikipedia. Small illustrations of organisms are displayed at the tips of the branches, to better visualize the morphological diversity of life on earth. Our assembled Tree of Life currently includes over 7000 taxonomic families (about half of the total family-level diversity) and its content will be gradually expanded through regular updates to cover all life on earth at family-level.


1999 ◽  
Vol 9 ◽  
pp. 95-118
Author(s):  
Sandra J. Carlson

The biological process of evolution – descent with modification – generates and structures the remarkable diversity of life on Earth today and in the geological past. Take a moment to consider the vast number of different kinds of living things: mushrooms, koalas, sunflowers, whales, mosquitoes, kelp, bacteria, tapeworms, lichens, clams, redwoods,…. the list could go on and on, seemingly forever. Without some understanding of how the diversity of life was generated, the scope of the diversity may seem overwhelming, perhaps even unknowable. Fortunately the structure of this extraordinary diversity, generated by the process of evolution, can be discovered using the methods of systematics. Evolution can be thought of as “an axiom from which systematic methods and concepts are deduced” (de Queiroz, 1988). Systematics, therefore, provides a way to organize the diversity surrounding us, and make sense of it in an evolutionary framework. Patterns of similarity and difference in morphology, genetics, and development — the evidence of evolution — can only be explained in an evolutionary context by means of systematics. No other method seeks to identify patterns that are evolutionary in origin, generated by the process of common descent.


2021 ◽  
Vol 50 (1) ◽  
Author(s):  
Nozomi Ando ◽  
Blanca Barquera ◽  
Douglas H. Bartlett ◽  
Eric Boyd ◽  
Audrey A. Burnim ◽  
...  

Sampling and genomic efforts over the past decade have revealed an enormous quantity and diversity of life in Earth's extreme environments. This new knowledge of life on Earth poses the challenge of understanding its molecular basis in such inhospitable conditions, given that such conditions lead to loss of structural changes and of function in biomolecules from mesophiles. In this review, we discuss the physicochemical properties of extreme environments. We present the state of recent progress in extreme environmental genomics. We then present an overview of our current understanding of the biomolecular adaptation to extreme conditions. As our current and future understanding of biomolecular structure–function relationships in extremophiles requires methodologies adapted to extremes of pressure, temperature, and chemical composition, advances in instrumentation for probing biophysical properties under extreme conditions are presented. Finally, we briefly discuss possible future directions in extreme biophysics. Expected final online publication date for the Annual Review of Biophysics, Volume 50 is May 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.


Zootaxa ◽  
2007 ◽  
Vol 1668 (1) ◽  
pp. 19-40 ◽  
Author(s):  
DAVID R. MADDISON ◽  
KATJA-SABINE SCHULZ ◽  
WAYNE P. MADDISON

The Tree of Life Web Project (ToL) provides information on the Internet about our current knowledge of the evolutionary tree of life and associated information about characteristics and diversity of life on Earth. Development of this open-access, database-driven system began in 1994; its official release was in 1996. Core scientific content in the project is compiled collaboratively by more than 540 biologists, all experts in particular groups of organisms, from over 35 countries.  Additional learning materials are contributed by over 200 students, teachers, and amateur scientists, while images, movies, and sounds are contributed by both of these groups and over 200 media-only contributors. Administration of the project follows a hierarchical, community-based model, with authors for different parts of the ToL chosen by the scientists working in that particular field. The goals of the project are to document all species on Earth, as well as all significant clades; to provide basic information about the phylogeny of life; to share this information with other databases and analytical tools; and to encourage understanding and appreciation for biodiversity, evolution, and the interrelationships of Earth's wealth of species. Here we provide an outline of the goals and history of the project; the current content, administration, architecture, contributors, and audience, the challenges we have faced, and the future of the project.


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