Adaptive Radiation, Ecological Opportunity, and Evolutionary Determinism

The American Naturalist, Journal Year: 2010, Volume and Issue: 175(6), P. 623 - 639

Published: April 22, 2010

Adaptive radiation refers to diversification from an ancestral species that produces descendants adapted use a great variety of distinct ecological niches. In this review, I examine two aspects adaptive radiation: first, it results opportunity and, second, is deterministic in terms its outcome and evolutionary trajectory. Ecological usually prerequisite for radiation, although some cases, can occur the absence preexisting opportunity. Nonetheless, many clades fail radiate seemingly presence opportunity; until methods are developed identify quantify opportunity, concept will have little predictive utility understanding priori when clade might be expected radiate. Although predicted by theory, replicated radiations only rarely, closely related poorly dispersing taxa found same region on islands or lakes. Contingencies types may preclude close similarity other situations. Whether unfold general sequence unclear because unreliability requiring phylogenetic reconstruction events. The synthesis ecological, phylogenetic, experimental, genomic advances promises make coming years golden age study radiation; natural history data, however, always crucial forces shaping adaptation diversification.

Language: Английский

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Macroevolution and the biological diversity of plants and herbivores

Proceedings of the National Academy of Sciences, Journal Year: 2009, Volume and Issue: 106(43), P. 18054 - 18061

Published: Oct. 8, 2009

Terrestrial biodiversity is dominated by plants and the herbivores that consume them, they are one of major conduits energy flow up to higher trophic levels. Here, we address processes have generated spectacular diversity flowering (>300,000 species) insect (likely >1 million species). Long-standing macroevolutionary hypotheses postulated reciprocal evolution adaptations subsequent bursts speciation given rise much this biodiversity. We critically evaluate various predictions based on coevolutionary theory. Phylogenetic reconstruction ancestral states has revealed evidence for escalation in potency or variety plant lineages' chemical defenses; however, defense been moderated tradeoffs alternative strategies (e.g., tolerance biotic agents). There still surprisingly scant novel traits reduce herbivory such evolutionary novelty spurs diversification. Consistent with hypothesis, there some diversification lagged behind, but nevertheless temporally correlated their host-plant clades, indicating colonization radiation insects diversifying plants. However, limited support role shifts Finally, a frontier area research, general conclusion our review, community ecology long-term history inexorably intertwined.

Language: Английский

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Why do plants produce so many terpenoid compounds?

New Phytologist, Journal Year: 2016, Volume and Issue: 220(3), P. 692 - 702

Published: Sept. 8, 2016

Summary All plants synthesize a suite of several hundred terpenoid compounds with roles that include phytohormones, protein modification reagents, anti‐oxidants, and more. Different plant lineages also hundreds distinct terpenoids, the total number such specialized terpenoids estimated in scores thousands. Phylogenetically restricted are implicated defense or attraction beneficial organisms. A popular hypothesis is ability to new arose incrementally by selection when, as result gradual changes their biotic partners enemies, ‘old’ were no longer effective, process dubbed ‘coevolutionary arms race’. Another posits often sheer diversity provides benefits single compound cannot. In this article, we review unique features biosynthetic apparatus terpenes facilitate production large numbers each species how facile genetic biochemical can lead further diversification terpenoids. We then discuss evidence relating hypotheses given ecological functions may be enhanced presence mixtures acquisition favor retention once original lost.

Language: Английский

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Ecological Opportunity and Adaptive Radiation

Annual Review of Ecology Evolution and Systematics, Journal Year: 2016, Volume and Issue: 47(1), P. 507 - 532

Published: Nov. 1, 2016

The process of adaptive radiation—the proliferation species from a single ancestor and diversification into many ecologically different forms—has been great interest to evolutionary biologists since Darwin. Since the middle last century, ecological opportunity has invoked as potential key understanding when how radiation occurs. Interest in topic accelerated research on experienced resurgence, fueled part by advances phylogenetic approaches studying diversification. Nonetheless, what term actually means, much less it mechanistically leads diversification, is currently debated; whether any predictive value or heuristic useful only for post hoc explanation also remains unclear. Recent recognition that change can occur rapidly timescale commensurate with processes suggests time synthesize study community assembly

Language: Английский

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Current trends in the evolutionary ecology of plant defence

Functional Ecology, Journal Year: 2010, Volume and Issue: 25(2), P. 420 - 432

Published: Oct. 13, 2010

Summary 1. In this essay I summarize current trends in the evolutionary ecology of plant defence, while advocating for approaches that integrate community with specific tests classic hypotheses. Several conclusions emerge. 2. The microevolution defence is perhaps best studied by reciprocal transplant experiments differentiated populations simultaneously manipulating presence herbivore(s) hypothesized to be agent(s) natural selection. 3. Although there continued interest costs argue some empirical estimating (e.g. genetic engineering) may provide limited insight into processes. 4. Essentially all plants employ several different lines against herbivory. It thus time abandon searching single silver bullet traits and simple trade‐off model (where are arbitrarily expected negatively covary across genotypes or species). We still know very little about which trait combinations most effective have repeatedly evolved together. Thus, our prominent theories a predicted between direct indirect defence) need revised. 5. Studies macroevolution enjoying renewed due available phylogenies analytical methods. general not currently surmisable, we will soon strong case studies evaluating both biotic abiotic drivers convergent evolution strategies role adaptive radiation lineages. 6. specificity proposed as final frontier understanding complexity plant–herbivore interactions. it abundantly clear can deploy highly defensive responses differentially perceived herbivore species, how such evolve physiologically regulated remains an important gap. Relatively straightforward methodologies now close loop perception herbivory, hormonal responses, production end‐products genotype species.

Language: Английский

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Toxic cardenolides: chemical ecology and coevolution of specialized plant–herbivore interactions

New Phytologist, Journal Year: 2012, Volume and Issue: 194(1), P. 28 - 45

Published: Jan. 31, 2012

Cardenolides are remarkable steroidal toxins that have become model systems, critical in the development of theories for chemical ecology and coevolution. Because cardenolides inhibit ubiquitous essential animal enzyme Na⁺/K⁺-ATPase, most insects feed on cardenolide-containing plants highly specialized. With a huge diversity forms, these secondary metabolites sporadically distributed across 12 botanical families, but dominate Apocynaceae where they found > 30 genera. Studies over past decade demonstrated patterns distribution among plant organs, including all tissue types, broad geographic gradients within species. Cardenolide production has genetic basis is subject to natural selection by herbivores. In addition, there strong evidence phenotypic plasticity, with biotic abiotic environment predictably impacting cardenolide production. Mounting indicates high degree specificity herbivore-induced Asclepias. While herbivores often sequester toxins, aposematic, possess several physiological adaptations (including target site insensitivity), specialists nonetheless negatively impacted cardenolides. reviewing both mechanisms evolutionary cardenolide-mediated interactions, we advance novel hypotheses suggest directions future work.

Language: Английский

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Phylogenetic Insights on Adaptive Radiation

Annual Review of Ecology Evolution and Systematics, Journal Year: 2010, Volume and Issue: 41(1), P. 251 - 270

Published: Nov. 2, 2010

Adaptive radiation is a response to natural selection and ecological opportunity involving diversification of species associated adaptations. Although evolutionary biologists have long speculated that adaptive responsible for most life's diversity, persistent confusion disagreement over some its fundamental questions prevented it from assuming central role in explaining the evolution biological diversity. Today, answers many these are emerging new wave integrative research combines phylogenetic trees with variety other data perspectives. In this review, I discuss how modern analyses (a) defining diagnosing radiation, (b)identifying factors underlying occurrence scope (c)diagnosing predictable patterns during (d) reconstructing history radiations.

Language: Английский

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Ecology of plant speciation

Taxon, Journal Year: 2010, Volume and Issue: 59(5), P. 1326 - 1366

Published: Oct. 1, 2010

Abstract Ecology affects each of the three principal processes leading to speciation: genetic differentiation among populations within species, acquisition reproductive isolation populations, and rise ecological such allowing them coexist. Until recently, however, ties between ecology speciation in plants have received relatively little attention. This paper reviews some exciting new insights into role speciation, focusing on angiosperms. I consider five main topics, including (1) determinants spatial scale species; (2) limits adaptive radiation increasing net rates plant diversification; (3) potential speciation; (4) contributions hybridization radiation, breadth clades; (5) diversification rate for individual lineages, species richness regional floras. Limited dispersal, especially seeds, favors at small scales is likely foster rapid narrow endemism. Meta­analyses show that minimum area required situ islands increases with gene flow various organisms. In angiosperms, fleshy fruits dispersed by vertebrates often increase distance over which seeds are dispersed, but can decrease it forest understories. Nutrient‐poor soils should work against evolution promote Selection adaptation different conditions drives a diversity roles attendant adaptations lineage. On islands, leads woodiness, monocarpy, developmental heterophylly, sexual dimorphism, as well differences habitat, growth form, floral morphology. Adaptive appears accelerate only clades. Extensive lineages has been ascribed early colonization, large amounts heritable variation, “genetic lines least resistance” upon selection could act, absence competitors, possession “key innovations” provide access novel resources. To these be added island area, organismal abundance, saturation space, synergism action limited dispersal divergent producing parallel radiations isolated regions. Data Hawaiian lobeliads suggest within­island Cyanea—involving divergence elevation flower tube length—saturates 0.6 1.5 Ma. pollinators an important mechanism pollinator partitioning isolation. longer nectar spurs mouth parts led increased Aquilegia other groups. A similar process may once tubular flowers evolve from cup­shaped blossoms. understories illuminated dim, greenish light, account predominance small, visually inconspicuous temperate tropical understory species. Hybridization stimulate forming transgressive phenotypes exceed range seen parental taxa, introgressing combinations. The likelihood so via most taxa intermediate divergence. Several appear occurred after hybridization, suggesting special extensive amount variation supplied refreshed syngameons. Rates greater herbs (especially annuals) vs. woody plants; animal­ wind­pollinated poorly seeds; families forms, pollination seed mechanisms, distributions; lower latitudes; higher evolution; hermaphroditic or monoecious dioecious earlier­maturing bilateral radial flowers; hummingbird­pollinated epiphytic terrestrial bromeliads orchids; differentiating along geographically cordilleras; young old Evidence last pattern may, artifact (auto)regressing (ln N) / t t. High orchids tied effective population sizes, intermittent drift alternating strong traits. Across massive was preceded major leaf vein density hydraulic conductance 140 110 Ma ago, photosynthetic than coexisting ferns gymnosperms. Based economic theory defense, this allocation anti­herbivore defenses, selecting low­cost qualitative toxins rather all­purpose highly expensive triggering arms' race angiosperm their herbivores. Finally, proxies latitude, rainfall, topographic heterogeneity, vegetation stratification. Cape Floristic Province roughly twice many expected its environmental conditions, reflecting short­distance associated poor myrmecochory Province, low regeneration competitive exclusion following fire.

Language: Английский

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Plant speciation through chromosome instability and ploidy change: Cellular mechanisms, molecular factors and evolutionary relevance

Current Plant Biology, Journal Year: 2014, Volume and Issue: 1, P. 10 - 33

Published: Aug. 1, 2014

Plant speciation and diversification strongly rely on structural changes in the nuclear genome, both at whole ploidy individual chromosome level. Phylogenetic, comparative mapping cytological studies have provided insights into evolutionary mechanisms that shape plant genome. These include major genome alterations, such as duplication hybridization (auto- allopolyploidy), but also comprise concomitant or independent occurrence of minor changes, aneuploidization dysploidy (inversions translocations). Despite relevance chromosomal instability a driver for evolution adaptation, little is yet known about cellular processes actually underlie these modifications. Here, this paper, we provide comprehensive overview somatic meiotic defects lead to polyploidy discuss their speciation. In addition, elaborate existence stress-induced integrity plants putative role boosting adaptive hostile environments.

Language: Английский

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Climate‐driven change in plant–insect interactions along elevation gradients

Functional Ecology, Journal Year: 2013, Volume and Issue: 28(1), P. 46 - 54

Published: July 22, 2013

Summary Global warming is predicted to dramatically alter communities' composition through differential colonization abilities, such as between sessile plants and their mobile herbivores. Novel interactions previously non‐overlapping species may, however, also be mediated by altered plants' responses herbivore attack. Syndromes of plant defences tolerance are driven inherited functional traits, biotic abiotic conditions, the geographical historical contingencies affecting community. Therefore, understanding climate change‐driven evolution towards a particular defence syndrome key forecasting in near future. In this paper, we first document variations herbivory, along altitudinal gradients that act ‘natural experiments’. We then use an empirical model predict how specialist abundance may shift with respect elevation Our field surveys experiment showed decrease herbivory elevation. However, contrary expectations, our meta‐regression analyses defences, particularly leaf toughness flavonoid compounds, tend higher at high elevations, while secondary metabolites no clear trend Based on those results, discuss communities species‐specific syndromes will change response climate‐driven altitudes. Particularly, from elevation, due protection against stress already ecologically fitted resist sudden increase pressure they likely experience during global change.

Language: Английский

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