Defining the speciation continuum

Evolution, Journal Year: 2021, Volume and Issue: 75(6), P. 1256 - 1273

Published: March 23, 2021

A primary roadblock to our understanding of speciation is that it usually occurs over a timeframe too long study from start finish. The idea continuum provides something solution this problem; rather than observing the entire process, we can simply reconstruct multitude events surround us. But what do really mean when talk about continuum, and help us understand speciation? We explored these questions using literature review online survey researchers. Although most researchers were familiar with concept thought was useful, revealed extensive disagreement actually tells This due partly lack clear definition. Here, provide an explicit definition compatible Biological Species Concept. That is, reproductive isolation. After outlining logic in light alternatives, explain why attempts process present-day populations will ultimately fail. then outline how think continue act as foundation for isolation surrounds

Language: Английский

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Sex chromosomes in meiotic, hemiclonal, clonal and polyploid hybrid vertebrates: along the ‘extended speciation continuum'

Philosophical Transactions of the Royal Society B Biological Sciences, Journal Year: 2021, Volume and Issue: 376(1833), P. 20200103 - 20200103

Published: July 25, 2021

We review knowledge about the roles of sex chromosomes in vertebrate hybridization and speciation, exploring a gradient divergences with increasing reproductive isolation (speciation continuum). Under early divergence, well-differentiated meiotic hybrids may cause Haldane-effects introgress less easily than autosomes. Undifferentiated are more susceptible to introgression form multiple (or new) chromosome systems hardly predictable dominance hierarchies. increased most vertebrates reach complete intrinsic isolation. Slightly earlier, some (linked ‘the extended speciation continuum') exhibit aberrant gametogenesis, leading towards female clonality. This facilitates evolution various allodiploid allopolyploid clonal (‘asexual’) hybrid vertebrates, where ‘asexuality' might be A comprehensive list ‘asexual' shows that they all evolved from parents were greater at intraspecific level (K2P-distances 5–22% based on mtDNA). These taxa inherited genetic determination by mostly undifferentiated chromosomes. Among few known sex-determining ‘asexuals', heterogamety (ZW) occurred twice as often male (XY). hypothesize pre-/meiotic aberrations all-female ZW-hybrids present promoting their evolution. Understanding preconditions produce or allopolyploids appears crucial for insights into sex, polyploidy. article is part theme issue ‘Challenging paradigm evolution: empirical theoretical focus (Part II)’.

Language: Английский

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The strength of reproductive isolating barriers in seed plants: Insights from studies quantifying premating and postmating reproductive barriers over the past 15 years

Evolution, Journal Year: 2022, Volume and Issue: 76(10), P. 2228 - 2243

Published: July 15, 2022

Speciation is driven by the evolution of reproductive isolating barriers that reduce, and ultimately prevent, substantial gene flow between lineages. Despite its central role in evolutionary biology, process can be difficult to study because it proceeds differently among groups may occur over long timescales. Due this complexity, we typically rely on generalizations empirical data describe understand process. Previous reviews isolation (RI) flowering plants have suggested prezygotic or extrinsic generally a stronger effect reducing compared postzygotic intrinsic barriers. Past conclusions rested relatively few estimates RI; however, RI become increasingly abundant past 15 years. We analyzed from recent studies quantifying multiple pre- postmating strengths across 89 taxa pairs using standardized metrics. Individual were average than individual barriers, total strength was approximately twice RI. These findings corroborate ecological divergence factors, as opposed solely accumulation genetic incompatibilities, are important speciation maintenance species boundaries plants. an emphasis literature asymmetric RI, found acted equally asymmetrically. Overall, variability 12 highlights great diversity mechanisms contribute plant diversification.

Language: Английский

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No link between population isolation and speciation rate in squamate reptiles

Proceedings of the National Academy of Sciences, Journal Year: 2022, Volume and Issue: 119(4)

Published: Jan. 20, 2022

Rates of species formation vary widely across the tree life and contribute to massive disparities in richness among clades. This variation can emerge from differences metapopulation-level processes that affect rates at which lineages diverge, persist, evolve reproductive barriers ecological differentiation. For example, populations quickly should form new faster than acquire more slowly. expectation implicitly links microevolutionary (the evolution populations) macroevolutionary patterns profound disparity speciation rate taxa). Here, leveraging extensive field sampling Neotropical Cerrado biome a biogeographically controlled natural experiment, we test role an important process-the propensity for population isolation-as control on lizards snakes. By quantifying genomic structure set codistributed taxa with phylogenetically independent rate, show broad-scale are decoupled demographic genetic promote isolates. Population isolation is likely critical stage many taxa, but our results suggest interspecific variability has little influence rates. These other stages speciation-including extent newly formed persist-are play larger controlling squamates.

Language: Английский

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Candidate‐species delimitation in Desmognathus salamanders reveals gene flow across lineage boundaries, confounding phylogenetic estimation and clarifying hybrid zones

Ecology and Evolution, Journal Year: 2022, Volume and Issue: 12(2)

Published: Feb. 1, 2022

Dusky Salamanders (genus

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The Ecology of Hybrid Incompatibilities

Cold Spring Harbor Perspectives in Biology, Journal Year: 2023, Volume and Issue: 16(9), P. a041440 - a041440

Published: Dec. 27, 2023

Ecologically mediated selection against hybrids, caused by hybrid phenotypes fitting poorly into available niches, is typically viewed as distinct from epistatic Dobzhansky-Muller incompatibilities. Here, we show how transgressive in hybrids manifests incompatibility. After outlining our logic, summarize current approaches for studying ecology-based on hybrids. We then quantitatively review QTL-mapping studies and find traits differing between parent taxa are polygenic. Next, describe verbal models of translate to phenotypic genetic fitness landscapes, highlighting emerging detecting polygenic Finally, a synthesis published data, report that trait transgression-and thus possibly extrinsic incompatibility hybrids-escalates with the divergence parents. discuss conceptual implications conclude ecological basis will facilitate new discoveries about mechanisms speciation.

Language: Английский

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How Important Is Sexual Isolation to Speciation?

Cold Spring Harbor Perspectives in Biology, Journal Year: 2024, Volume and Issue: unknown, P. a041427 - a041427

Published: Feb. 12, 2024

A central role for sexual isolation in the formation of new species and establishment boundaries has been noticed since Darwin is frequently emphasized modern literature on speciation. However, an objective evaluation when how plays a speciation carried out few taxa. We discuss three approaches assessing importance relative to other reproductive barriers, including evolutionary rate trait differentiation, strength sympatry, long-term persistence diverging forms. First, we evaluate evidence as whether evolves faster than barriers during early stages divergence. Second, available strong or stronger between closely related sympatric species. Finally, consider effect persistence, barriers. highlight challenges our knowledge opportunities improve upon understanding from different phases process.

Language: Английский

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The evolutionary network of whiptail lizards reveals predictable outcomes of hybridization

Science, Journal Year: 2022, Volume and Issue: 377(6607), P. 773 - 777

Published: Aug. 11, 2022

Hybridization between diverging lineages is associated with the generation and loss of species diversity, introgression, adaptation, changes in reproductive mode, but it unknown when why results these divergent outcomes. We estimate a comprehensive evolutionary network for largest group unisexual vertebrates use to understand outcomes hybridization. Our show that rates introgression decrease time since divergence suggest must attain threshold before hybridization transitions unisexuality. Rates also predict genome-wide patterns genetic diversity whiptail lizards. These distinguish among models have not previously been tested can be predictable.

Language: Английский

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A need for standardized reporting of introgression: Insights from studies across eukaryotes

Evolution Letters, Journal Year: 2022, Volume and Issue: 6(5), P. 344 - 357

Published: July 25, 2022

With the rise of affordable next-generation sequencing technology, introgression-or exchange genetic materials between taxa-has become widely perceived to be a ubiquitous phenomenon in nature. Although this claim is supported by several keystone studies, no thorough assessment frequency introgression across eukaryotes nature has been performed date. In manuscript, we aim address knowledge gap examining patterns eukaryotes. We collated single statistic, Patterson's D, which can used as test for 123 studies further assess how taxonomic group, divergence time, and technology influence reports introgression. Overall, mostly measured plants vertebrates, with less attention given rest Eukaryotes. find that most frequently metrics detect are difficult compare even more so biological systems due differences study effort, reporting standards, methodology. Nonetheless, our analyses reveal intriguing patterns, including observation technologies may bias values D differ throughout course speciation process. Together, these results suggest need unified approach quantifying natural communities highlight important areas future research better assessed once met.

Language: Английский

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Use of Genomic Resources to Assess Adaptive Divergence and Introgression in Oaks

Forests, Journal Year: 2021, Volume and Issue: 12(6), P. 690 - 690

Published: May 27, 2021

Adaptive divergence is widely accepted as a contributor to speciation and the maintenance of species integrity. However, mechanisms leading reproductive isolation, genes involved in adaptive divergence, traits that shape adaptation wild changes climate are still largely unknown. In studying role ecological interactions environment-driven selection, trees have emerged potential model organisms because their longevity large genetic diversity, especially natural habitats. Due recurrent gene flow among with different preferences, oaks arose early 1970s for understanding how can occur face interspecific flow, what we mean by “species” when geographically genomically heterogeneous introgression seems undermine species’ coherence. this review, provide an overview recent research into genomic underpinnings integrity flow. We review analytical tools instrumental better isolation oaks. evidence oak coherent entities, focusing on sympatric populations ongoing discuss hypotheses regarding linking isolation. As evolution drought- freezing-tolerance been key parallel diversification oaks, investigate question whether same or similar set drought stress tolerance across taxa sections. Finally, propose future directions hybridization change.

Language: Английский

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