Coevolution

The frontline of avian brood parasite–host coevolution

by William Feeney

Feeney, W. E., Welbergen, J. A., Langmore, N. E.

The interactions between avian interspecific brood parasites and their hosts provide tractable and informative systems... more The interactions between avian interspecific brood parasites and their hosts provide tractable and informative systems for investigating coevolution. Generally, these investigations have emphasized the egg and chick stages of the coevolutionary arms race; however, recent studies demonstrate that coevolution operates at all stages of the host nesting cycle and emphasize the importance of reciprocal adaptations prior to deposition of the parasite egg in the host nest: the ‘frontline’ of the arms race. Here we review the diversity of adaptations at the frontline and its implications for our understanding of brood parasite–host relationships. Coevolution at the frontline can fundamentally shape the life histories, morphologies, physiologies and behaviours of both brood parasites and their hosts, and influences the trajectories and outcomes of their subsequent coevolutionary interactions. We advocate the incorporation of frontline interactions in empirical and theoretical investigations of brood parasite–host arms races to provide a more holistic understanding of the coevolutionary processes in these systems.

Coevolution and the Web of Life

by Rodrigo Medel

Learned recognition of brood parasitic cuckoos in the superb fairy-wren Malurus cyaneus.

by William Feeney

Langmore, N. E., Feeney, W. E., Crowe-Riddell, J., Luan, H., Louwrens, K. M. & Cockburn, A.

Cuckoo hosts defend themselves against parasitism by means of mobbing, egg rejection, and chick rejection. However,... more Cuckoo hosts defend themselves against parasitism by means of mobbing, egg rejection, and chick rejection. However, each of these defenses is prone to costly recognition errors, and hosts are therefore more likely to deploy these defenses if they observe a cuckoo in the vicinity of their nest. The success of such response plasticity depends on accurate recognition of sympatric cuckoo species, but the mechanism by which hosts recognize cuckoos is largely unknown. Here, we use microgeographic variation in exposure to cuckoos in superb fairy-wren (Malurus cyaneus) hosts to test whether recognition of cuckoos is dependent on learning. We compare mobbing by superb fairy-wrens in response to freeze-dried specimens of a shining bronze-cuckoo (Chalcites lucidus) and a honeyeater control (Lichenostomus penicillatus) at 2 heavily parasitized sites and 2 rarely parasitized sites. Hosts at heavily parasitized sites mobbed the cuckoo intensively, including production of a distinctive whining call that appears to instigate group mobbing. By contrast, hosts at the rarely parasitized sites showed little reaction to the cuckoo, and their responses were similar to those given to the control. Furthermore, individuals with past experience of cuckoos mobbed the cuckoo specimen even when cuckoos were absent from the site, and did so significantly more than naive individuals. The extreme variation in response to cuckoos on such a small geographic scale and in relation to past exposure to cuckoos is consistent with learned recognition of cuckoos rather than local genetic adaptation.

Natural selection on floral traits in Aconitum lycoctonum (Ranunculaceae) in different regions of its distribution, with special regard to the presence/absence of …

by Tobias Jeppsson

HIV-1 Protease and Substrate Coevolution Validates the Substrate Envelope As the Substrate Recognition Pattern.

by Aysegul Ozen

A. Ozen, T. Haliloglu, C. A. Schiffer, J Chem Theory Comput. 8(2), 703 (Jan 2, 2012)

Drug resistance of HIV-1 protease alters the balance in the molecular recognition events in favor of substrate... more Drug resistance of HIV-1 protease alters the balance in the molecular recognition events in favor of substrate processing versus inhibitor binding. To develop robust inhibitors targeting ensembles of drug-resistant variants, the code of this balance needs to be cracked. For this purpose, the principles governing the substrate recognition are required to be revealed. Previous crystallographic studies on the WT protease–substrate complexes showed that the substrates have a conserved consensus volume in the protease active site despite their low sequence homology. This consensus volume is termed as the substrate envelope. The substrate envelope was recently reevaluated by taking the substrate dynamics into account, and the dynamic substrate envelope was reported to better define the substrate specificity for HIV-1 protease. Drug resistance occurs mostly through mutations in the protease, occasionally accompanied by cleavage site mutations. In this study, three coevolved protease–substrate complexes (AP2VNC-p1V82A, LP1′Fp1-p6D30N/N88D, and SP3′Np1-p6D30N/N88D) were investigated for structural and dynamic properties by molecular modeling and dynamics simulations. The results show the substrate envelope is preserved by these cleavage site mutations in the presence of drug-resistance mutations in the protease, if not enhanced. This study on the conformational and mutational ensembles of protease–substrate complexes validates the substrate envelope as the substrate recognition motif for HIV-1 protease. The substrate envelope hypothesis allows for the elucidation of possible drug resistance mutation patterns in the polyprotein cleavage sites.

Devonian pearls and ammonoid−endoparasite co−evolution

by Christian Klug

by KENNETH DE BAETS, CHRISTIAN KLUG, and DIETER KORN

Raised shell projections on the inner shell walls that form pits on the internal moulds of Devonian ammonoids have... more Raised shell projections on the inner shell walls that form pits on the internal moulds of Devonian ammonoids have been
known for several decades. New specimens from Morocco reveal novel details of these structures; most, if not all, of
which consist of a capsule of ammonoid shell that covers tiny tubes attached to the outer (= lateral or ventral) shell wall
from the inside. In accordance with comparable Recent occurrences of similar structures in molluscs, we use the term
“pearls” for these structures and the pits they form on the internal moulds. The nature of these encapsulated tubes is de−
scribed and discussed. Because of the presence of these tubes inside the pearls, pearl arrangement, and their similarity to
Recent mollusc occurrences, the tubes are interpreted as traces of parasitoses. The pearls and pits were grouped into five
types based on differences in morphology, size, and arrangement. Then, having used these traits to perform a simple
cladistic analysis, the resulting cladogram was compared to the phylogeny of ammonoids. Based on this comparison, it
appears likely that the parasites underwent a co−evolution with the ammonoids, which lasted 10 to 15 Ma. Patterns of evo−
lutionary events include co−speciation, “drowning on arrival” (end of parasite lineage near base of a new host clade), and
“missing the boat” (parasite lineage does not adapt to a new host clade, thus not evolving a new parasite clade). Because of
the lack of fossilised soft tissue, only speculations can be made about the systematic affiliation of the parasites, their
life−cycle, infection strategy, and ecological framework. Some co−occurring bivalves also have pits reminiscent to struc−
tures caused by trematodes in Recent forms. Based on the available information, the tubes are interpreted as artefacts of
trematode infestations, which, if correct, would extend the fossil record of parasitic trematodes into the Early Devonian.

Mutualism variation in the nodulation response to nitrate

by Amanda Stock

Pattern and timing of diversification in Yucca (Agavaceae): specialized pollination does not escalate rates of diversification

by Christopher Smith

Natural History Note

by Christopher Smith

Arms Race Coevolution: The Local and Geographical Structure of a Host–Parasite Interaction

by Rodrigo Medel

Co-authored with M.A. Mendez, C.G. Ossa & C. Botto-Mahan
Evolution Education & Outreach 2910.

Consideration of complex geographic patterns of mreciprocal adaptation has provided insight into new features of the... more Consideration of complex geographic patterns of mreciprocal adaptation has provided insight into new features of the coevolutionary process. In this paper, we provide mecological, historical, and geographical evidence for coevolution under complex temporal and spatial scenarios that include intermittent selection, species turnover across localities, and a range of trait match/mismatch across populations. Our study focuses on a plant host–parasitic plant interaction endemic to arid and semiarid regions of Chile. The long spines of Chilean cacti have been suggested to evolve under parasite-mediated selection as a first line of defense against the mistletoe Tristerix aphyllus. The mistletoe, in turn, has evolved an extremely long morphological structure that emerges from the seed endosperm (radicle) to reach the host cuticle. When spine length was traced along cactus phylogenies, a significant association between spine length and parasitism was detected, indicating that defensive traits evolved in high correspondence with the presence or absence of parasitism in two cactus lineages. Assessment of spine-radicle matching across populations revealed a potential for coevolution in 50% of interaction pairs. Interestingly, hot spots for coevolution did not distribute at random across sites. On the contrary, interaction pairs showing high matching values occur mostly in the northern distribution of the interaction, suggesting a geographical structure for coevolution in this system. Only three sampled interaction pairs were so mismatched that reciprocal selection could not occur given current trait distributions. Overall, different lines of evidence indicate that arms-race coevolution is an ongoing phenomenon that occurs in the global system of interconnected populations.

Olfactive detection of fig wasps as prey by the ant Crematogaster scutellaris (Formicidae; Myrmicinae)

by Welmoed Out

2003, Naturwissenschaften 90 (10), 456-459

In the species-specific and obligate mutualism between the fig (Ficus carica) and its pollinator (the fig wasps... more In the species-specific and obligate mutualism between the fig (Ficus carica) and its pollinator (the fig wasps Blastophaga psenes), a third participant, the ant Crematogaster scutellaris, is a predator of the wasps. Here, we ask how ant workers can rapidly localise such prey, whose availability is limited in time and space. Using a Y-tube olfactometer, we tested ant response to odours emitted by different types of figs (receptive female, ripe female or male figs) and by fig wasps (pollinators or non-pollinators). We demonstrate that ants were significantly attracted only to odours emitted by pollinators, either alone or associated with odours of male figs (releasing wasps). Detection of prey odour by ants is an important trait that can explain their observed high rate of predation on pollinators, and could have important implications on the stability of the fig/fig wasp mutualism.

Feminist Praxis, Organic Inquiry goals, and Axiology in Research as applied to Coevolution in Sacred Education – A Narrative

by Riki Sarah Dennis

This short narrative is a treatment of feminist praxis as applied to coevolution in sacred education. It harnesses... more This short narrative is a treatment of feminist praxis as applied to coevolution in sacred education. It harnesses organic inquiry, and utilizes axiology in research - applied to the subject of coevolution in sacred education! Coevolution, which stems from Systems Theory, is woven throughout this narrative. Participants in any education are human, with the complex inner landscape only the language of systems theory can hope to describe. It isn’t a sterile narrative – sacred education seeks to recognize and promote, rather than homogenize, the rich inner landscape of human beings, including the author’s voice.

Maintenir la réciprocité pour mieux coexister? Ethnographie du récit kirghiz des relations dynamiques entre les hommes et les loups

by Nicolas Lescureux

PhD Thesis defended in 2007

Confronté aux difficultés des différentes disciplines à dégager les propriétés interactives des relations... more Confronté aux difficultés des différentes disciplines à dégager les propriétés interactives des relations hommes-loups, j'ai interrogé les Kirghiz sur leurs relations, dans la synchronie et la diachronie. J'ai adopté une démarche ethno-éthologique intégrant le comportement de l'animal et la manière dont il est perçu afin de déterminer ses influences sur les savoirs et les pratiques humaines.
Intelligent et doué d'intentionnalité, le loup se voit attribuer par les Kirghiz une intériorité similaire à la leur et apparaît comme un alter ego. Pratiques d'élevage et de chasse viennent confirmer cette conception et participent à son émergence. Il apparaît ainsi que les Kirghiz se trouvent engagés dans une interrelation faite d'interactions réciproques. L'impact de la chute de l'URSS sur les pratiques humaines puis sur les comportements des loups montre le caractère dynamique des interrelations et conduit à considérer la relation des Kirghiz avec les loups comme une co-évolution.

Considering the difficulties of disciplinary approaches to grasp the interactive properties of human-wolf relationships, I questionned the Kyrgyz on their relationships in synchrony and diachrony. I adopted an ethno-ethological approach which integrate the animal's behaviour and the way it is perceived in order to determine their influences on knowledge and practices.
Intelligent, endowed with intentionality and reflectivity, the wolf is credited by Kyrgyz with the same interiority as human one and thus appears as an alter ego. Kyrgyz's practices bears out their conception of the world and also takes part in its emergence. Thus, it appears that the Kyrgyz are engaged with wolves in an inter-relation founded on reciprocal interactions. The fall of USSR and its consequences on human practices and thus on wolves behaviour allows us to bring to light the dynamic property of Kyrgyz-wolves relationship and drives us to consider it as a co-evolution.

Missing and forbidden links in mutualistic networks

by Pedro Jordano

Co-authored with Olesen, J.M., Bascompte, J., Dupont, Y.L., Elberling, H.  2010. Proceedings of the Royal Society of London Series B-Biological Sciences, 278: 725-732.

doi: 10.1098/rspb.2010.1371

Ecological networks are complexes of interacting species, but not all potential links among species are realized.... more Ecological networks are complexes of interacting species, but not all potential links among species are realized. Unobserved links are either missing or forbidden. Missing links exist, but require more sampling or alternative ways of detection to be verified. Forbidden links remain unobservable, irrespective of sampling effort. They are caused by linkage constraints. We studied one Arctic pollination network and two Mediterranean seed-dispersal networks. In the first, for example, we recorded flower-visit links for one full season, arranged data in an interaction matrix and got a connectance C of 15 per cent. Interaction accumulation curves documented our sampling of interactions through observation of visits to be robust. Then, we included data on pollen from the body surface of flower visitors as an additional link ‘currency’. This resulted in 98 new links, missing from the visitation data. Thus, the combined visit–pollen matrix got an increased C of 20 per cent. For the three networks, C ranged from 20 to 52 per cent, and thus the percentage of unobserved links (100 − C) was 48 to 80 per cent; these were assumed forbidden because of linkage constraints and not missing because of under-sampling. Phenological uncoupling (i.e. non-overlapping phenophases between interacting mutualists) is one kind of constraint, and it explained 22 to 28 per cent of all possible, but unobserved links. Increasing phenophase overlap between species increased link probability, but extensive overlaps were required to achieve a high probability. Other kinds of constraint, such as size mismatch and accessibility limitations, are briefly addressed.

Evolution and coevolution in mutualistic networks

by Pedro Jordano

Co-authored with Guimarães Jr., P.R. and Thompson, J.N. 2011. Published in Ecology Letters, (2011) 14: 877–885

A major current challenge in evolutionary biology is to understand how networks of interacting species shape the... more A major current challenge in evolutionary biology is to understand how networks of interacting species shape the coevolutionary process. We combined a model for trait evolution with data for twenty plant-animal assemblages to explore coevolution in mutualistic networks. The results revealed three fundamental aspects of coevolution in species-rich mutualisms. First, coevolution shapes species traits throughout mutualistic networks by speeding up the overall rate of evolution. Second, coevolution results in higher trait complementarity in interacting partners and trait convergence in species in the same trophic level. Third, convergence is higher in the presence of super-generalists, which are species that interact with multiple groups of species. We predict that worldwide shifts in the occurrence of super-generalists will alter how coevolution shapes webs of interacting species. Introduced species such as honeybees will favour trait convergence in invaded communities, whereas the loss of large frugivores will lead to increased trait dissimilarity in tropical ecosystems.

Eco-evolutionary dynamics of mutualists and exploiters

by Emily Jones

Jones, E. I., R. Ferriere, and J. L. Bronstein. 2009. American Naturalist 174:780-794.

With the growing recognition of exploiters as a prominent and enduring feature of many mutualisms, there is a need to... more With the growing recognition of exploiters as a prominent and enduring feature of many mutualisms, there is a need to understand the ecological and evolutionary dynamics of mutualisms in the context of exploitation. Here, we model coevolution between mutualist and exploiter birth rates, using an obligate pollinating seed parasite mutualism associated with a nonpollinating exploiter as a reference system. In this system, mutualist and exploiter larvae parasitize the host plant, competing for and consuming seeds. Evolution of the mutualist determines which exploiters can invade successfully. Subsequent coevolution with an exploiter has a strong, predictable influence on mutualist-exploiter coexistence, mutualist and exploiter phenotypes, and species abundances. Weak mutualist competition promotes "evolutionary purging" of the exploiter, while weak exploiter competition leads to "evolutionary suicide" of the system. When stable, long-term coexistence occurs, we identify two main "trait-abundance syndromes" that have three novel implications. (1) Persistent, highly parasitic exploiters can be favored by coevolution. (2) Even then, the density of coevolved mutualists can be high. (3) Low plant density results primarily from the evolution of mutualist, not exploiter, birth rate and density. To evaluate these predictions, studies are needed that identify and compare populations with and without exploiters and compare life-history traits of mutualists and exploiters.

Mistletoe seed dispersal by a marsupial

by Guillermo Amico

Amico GC & MA Aizen. 2000. Mistletoe seed dispersal by a marsupial. Nature 408: 929-930

Geographic variation in fruit colour is associated with contrasting seed disperser assemblages in a south‐Andean mistletoe

by Guillermo Amico

Amico GC, MA Rodriguez-Cabal & MA Aizen. 2011. Geographic variation in fruit colour is associated with contrasting seed disperser assemblages in a south-Andean mistletoe. Ecography 34: 318-326

Redes complejas de interacciones planta-animal

by Pedro Jordano

co-authored with D. Vázquez y J. Bascompte. 2009. En: Medel, R., Aizen, M., Zamora, R.(eds). Ecología y evolución de las interacciones planta-animal: conceptos y aplicaciones. Editorial Universitaria, Santiago, Chile. Págs.: 17-41.

Coevolution in Multispecific Interactions among Free-Living Species

by Pedro Jordano

Special Issue on "Coevolution". Evolution: Education and Outreach 3: 40-46. 2010.

Ecological interactions among species are the backbone of biodiversity. Interactions take a tremendous variety of... more Ecological interactions among species are the backbone of biodiversity. Interactions take a tremendous variety of forms in nature and have pervasive consequences for the population dynamics and evolution of species. A persistent challenge in evolutionary biology has been to understand how coevolution has produced complex webs of interacting species, where a large number of species interact through mutual dependences (e.g., mutualisms) or influences (e.g., predator–prey interactions in food webs). Recent work on megadiverse species assemblages in ecological communities has uncovered interesting repeated patterns that emerge in these complex networks of multispecies interactions. They include the presence of a core of super-generalists, proper patterns of interaction (that resemble nested chinese boxes), and multiple modules that act as the basic blocks of the complex network. The structure of multispecies interactions resembles other complex networks and is central to understanding its evolution and the consequences of species losses for the persistence of the whole network. These patterns suggest both precise ways on how coevolution goes on beyond simple pairwise interactions and scales up to whole communities.