Coevolutionary analyses of the relationships between piroplasmids and their hard tick hosts

Host–parasite coevolution is a key driver of biological diversity. To examine the evolutionary relationships between piroplasmids and their hard tick hosts, we calculated the molecular clock and conducted phylogenetic analyses of both groups. Based on our results, we conclude that the divergence time of piroplasmids (~56 Mya) is later than divergence time of their hard tick hosts (~86 Mya). From analyses of the evolution of both piroplasmid and vector lineages and their association, we know that hard ticks transmit piroplasmids with high genus specificity and low species specificity.     

Evolution of host specificity in fleas: is it directional and irreversible?

Evolutionary trends in the evolution of host specificity have been the focus of much discussion but little rigorous empirical testing. On the one hand, specialization is often presumed to lead irreversibly into evolutionary dead ends and little diversification; this would mean that generalists might evolve into specialists, but not vice versa. On the other hand, low host specificity may limit the risk of extinction and provide more immediate fitness benefits to parasites, such that selection may favour evolution toward a generalist strategy. Here, we test for directionality in the evolution of host specificity using a large data set and phylogenetic information on 297 species of fleas parasitic on small mammals. The analyses determined whether host specificity, measured both as the number of host species exploited and their taxonomic diversity, was related to clade rank of the flea species, or the number of branching events between an extant species and the root of the phylogenetic tree (i.e., the total path length from the root of the tree to the species). Based on regression analyses, we found positive relationships between the number of host species used and clade rank across all 297 species, as well as within one (Hystrichopsyllidae) of four large families and one of seven large genera investigated separately; in addition, we found a positive relationship between the taxonomic diversity of host species used and clade rank in another of the seven genera. These results suggest a slight evolutionary trend of decreasing host specificity. Using a much more conservative likelihood ratio test, however, a random walk, or null model, of evolution could not be discarded in favour of the directional trends in all cases mentioned above. Still, these results suggest that host specificity may have tended to decrease in many flea lineages, a process that could have been driven by the benefits of exploiting a wide range of host species.     

Complex evolution of gypsy in Drosophilid species

In an endeavor to contribute to the comprehension of the evolution of transposable elements (TEs) in the genome of host species, we investigated the phylogenetic relationships of sequences homologous to the retrotransposon gypsy of Drosophila melanogaster in 19 species of Drosophila, in Scaptodrosophila latifasciaeformis, and in Zaprionus indianus. This phylogenetic study was based on approximately 500 base pairs of the env gene. Our analyses showed considerable discrepancy between the phylogeny of gypsy elements and the relationship of their host species, and they allow us to infer a complex evolutionary pattern that could include ancestral polymorphism, vertical transmission, and several cases of horizontal transmission.     

Phylogenetic and biogeographical relationships among some holarctic frog lung flukes (Digenea: Haematoloechidae).

A phylogenetic study of 8 North American and European species of frog lung flukes belonging to Haematoloechus was conducted using approximately 850 to 1,000 bases of the intemal transcribed spacer region (ITS 1 + 5.8S + ITS 2) and 1,250 bases of the large subunit (LSU) of the nuclear ribosomal DNA. Adequate phylogenetic resolution could not be obtained from 5.8S or ITS 2 data. Analysis of ITS 1 data produced 2 equally parsimonious trees that differed only in the position of Haematoloechus breviplexus relative to H. medioplexus and H. varioplexus. Single, identical trees were produced by analysis of both LSU sequence data and a data set comprised of all ITS and LSU data. All trees demonstrated 3 distinct evolutionary lineages within the Holarctic Haematoloechus examined. The results confirmed the taxonomic validity of H. abbreviatus and demonstrated that the presence or absence of extracecal uterine loops is not a character meaningful to the recognition of evolutionary lineages or differentiation of genera. Examination of ITS sequence data revealed almost no intraspecific variation within 5 species of Haematoloechus and demonstrated an approximately 150-base indel common to the North American H. longiplexus and the European H. asper. Two of 3 clades revealed by the phylogenetic analyses are comprised of both European and North American species, indicating that lineages of Haematoloechus arose before the breakup of Laurasia and radiated after Eurasia and North America split. Within each of 3 evolutionary lineages, members share similar patterns of arthropod host specificity distinct from patterns found in the other lineages. This suggests that second intermediate host specificity may be a trait that has been conserved through evolutionary time.     

Mistletoe species richness patterns are influenced more by host geographic range than nitrogen content

Mistletoes are hemiparasites that access water and nutrients from their hosts. Previous studies have suggested that host genera with high nitrogen are parasitized by more mistletoe species but these studies failed to take into account phylogenetic relationships among host genera. Our main question was whether more mistletoe species parasitize host genera with high nitrogen content when phylogenetic relationships were controlled. We also asked whether patterns in mistletoe parasitism were related to host geographic range size, host fruit type and host spinescence. Overall, we found no difference between conventional and phylogenetically controlled analyses. We also found no evidence for higher mistletoe species richness on host genera with high nitrogen, fleshy fruits or spinescence. However, similar to findings for animal parasites, we found that host genera with large geographic range had higher mistletoe species richness. This is likely because a greater number of mistletoe species will encounter hosts that have a greater geographic distribution. Mistletoe studies frequently assume that nitrogen status drives patterns in mistletoe parasitism but our study suggests that macroecological patterns in mistletoe assemblages are primarily determined by host geographic range.     

Life-History Correlates of Placental Structure in Eutherian Evolution

The eutherian placenta shows remarkable evolutionary plasticity. To date, however, success in identifying selection pressures behind the observed diversity of placental structures has been limited. Evolutionary convergence among definitive placental morphologies and between placental morphologies and life-history variables can be used to suggest functions of derived aspects of placentation. In this paper, we use, for the first time, a comprehensive phylogenetic comparative approach to map phenotypic character states of both placental morphologies and life-history characteristics of species onto hypotheses of phylogenetic relationships in Eutheria. We employ phylogenetic methods for ancestral reconstruction, mutational mapping, and association analysis to resolve associations between five aspects of placental structure and to identify dominant combinations, or syndromes, of placental morphology. We map twenty life-history characters onto the eutherian phylogeny to examine how they correlate, over evolutionary time, with the multivariate diversification of placental structures. We identify two distinct eutherian constellations, based on associations between life-history and placental structure, which broadly reflect a dichotomy between slow and fast life-history strategies. In addition, we suggest that the observed association between placental invasiveness and group size is indicative of the effect of social behavior on the utility of genomic-imprinting in eutherian evolution.     

New evolutionary lineages, unexpected diversity, and host specificity in the parabasalid genus Tetratrichomonas

We studied morphological and molecular polymorphism of 53 Tetratrichomonas isolates obtained from amphibian, reptilian, mammalian hosts, and from a slug with the aid of protargol staining and analyses of ITS1-5.8S rRNA-ITS2, SSU rRNA, and alpha-tubulin gene sequences. The phylogenetic tree based on the concatenate of all sequences showed the monophyly of the genus Tetratrichomonas with respect to the genus Trichomonas. Our data suggest that two parabasalid genera, Pentatrichomonoides and Trichomonoides, may belong to the genus Tetratrichomonas. Tetratrichomonas isolates were divided into 16 robust host-specific and monophyletic groups that probably represent separate, mostly new, species. As only five Tetratrichomonas species were described from the examined host taxa so far, our study uncovered considerable species diversity within the genus. The wide host range, high level of species-specific host specificity, and newly revealed biodiversity make the genus Tetratrichomonas a valuable model for studying evolution of parasites.     

Host longevity and parasite species richness in mammals

Hosts and parasites co-evolve, with each lineage exerting selective pressures on the other. Thus, parasites may influence host life-history characteristics, such as longevity, and simultaneously host life-history may influence parasite diversity. If parasite burden causes increased mortality, we expect a negative association between host longevity and parasite species richness. Alternatively, if long-lived species represent a more stable environment for parasite establishment, host longevity and parasite species richness may show a positive association. We tested these two opposing predictions in carnivores, primates and terrestrial ungulates using phylogenetic comparative methods and controlling for the potentially confounding effects of sampling effort and body mass. We also tested whether increased host longevity is associated with increased immunity, using white blood cell counts as a proxy for immune investment. Our analyses revealed weak relationships between parasite species richness and longevity. We found a significant negative relationship between longevity and parasite species richness for ungulates, but no significant associations in carnivores or primates. We also found no evidence for a relationship between immune investment and host longevity in any of our three groups. Our results suggest that greater parasite burden is linked to higher host mortality in ungulates. Thus, shorter-lived ungulates may be more vulnerable to disease outbreaks, which has implications for ungulate conservation, and may be applicable to other short-lived mammals.     

Evolution of host breadth in broad interactions: mycorrhizal specificity in East Asian and North American rattlesnake plantains (Goodyera spp.) and their fungal hosts

Host breadth is often assumed to have no evolutionary significance in broad interactions because of the lack of cophylogenetic patterns between interacting species. Nonetheless, the breadth and suite of hosts utilized by one species may have adaptive value, particularly if it underlies a common ecological niche among hosts. Here, we present a preliminary assessment of the evolution of mycorrhizal specificity in 12 closely related orchid species (genera Goodyera and Hetaeria) using DNA‐based methods. We mapped specificity onto a plant phylogeny that we estimated to infer the evolutionary history of the mycorrhiza from the plant perspective, and hypothesized that phylogeny would explain a significant portion of the variance in specificity of plants on their host fungi. Sampled plants overwhelmingly associated with genus Ceratobasidium, but also occasionally with some ascomycetes. Ancestral mycorrhizal specificity was narrow in the orchids, and broadened rarely as Goodyera speciated. Statistical tests of phylogenetic inertia suggested some support for specificity varying with increasing phylogenetic distance, though only when the phylogenetic distance between suites of fungi interacting with each plant taxon were taken into account. These patterns suggest a role for phylogenetic conservatism in maintaining suits of fungal hosts among plants. We stress the evolutionary importance of host breadth in these organisms, and suggest that even generalists are likely to be constrained evolutionarily to maintaining associations with their symbionts.     

Identity and phylogenetic status of two sibling gall midge species (Diptera: Cecidomyiidae: Contarinia) on the perennial herb Vincetoxicum hirundinaria

Abstract Contarinia comprises one of the largest genera among gall forming midges of Cecidomyiidae, where identification and species relationships are uncertain. Using data on phenological development, morphometric relationships and mitochondrial DNA, the status of two isomorphic species, C. vincetoxici and C. asclepiadis , which attack the perennial herb Vincetoxicum hirundinaria , were investigated. Data show that they are two distinct species. In rearing experiments, the two gall midges were shown to have different times of adult emergence. Small differences in wing morphology were revealed that separate the two species from each other, as well as from C. loti , the type species of Contarinia . Sequence differences in the mitochondrial cytochrome b gene corroborate the specific status of C. vincetoxici and C. asclepiadis . Furthermore, a phylogenetic analysis, also including three other Contarinia species, showed that the two gall midges on V. hirundinaria are not even the most closely related species, suggesting two separate evolutionary colonizations of the host plant.     

Molecular phylogeny of the entomopathogenic fungi of the genus Cordyceps (Ascomycota: Clavicipitaceae) and its evolutionary implications

Abstract Cordyceps is an endoparasite ascomycetous genus containing approximately 450 species with a diversity of insect hosts, traditionally included in the family Clavicipitaceae of Ascomycota. Establishing the relationships among species with a varied range of morphologies and hosts is of importance to our understanding of the phylogeny and co‐evolution of parasites and hosts in entomopathogenic ascomycetes. To this end, we used a combination of molecular index and morphological characters from 40 representative species to carry out comprehensive molecular phylogenetic analyses. Based on the phylogenetic tree, we used the program DISCRETE for inferring the rates of evolution and finding ancestral states of morphological character. The phylogenetic analyses revealed two important points. (i) Types of perithecia attached to stroma reflected an evolutionary trend in Cordyceps. The vertically immersed perithecia form was the ancestral state, superficial and obliquely immersed perithecia were derived characters, obliquely immersed was irreversible. Species with obliquely immersed perithecia were in a closely related group and were the derived group. (ii) A strong correlation between fungal relatedness and the microhabitat supported the hypothesis that the host jumps through commingling in soil microhabitats. Based on the results of these analyses, host switching explains the diversity of entomopathogenic fungi of the genus Cordyceps.     

The repertoire of serine rhomboid proteases of piroplasmids of importance to animal and human health

Babesia, Theileria and Cytauxzoon are tick-borne apicomplexan protozoans of the order Piroplasmida, notorious for the diseases they cause in livestock, pets and humans. Host cell invasion is their Achilles heel, allowing for the development of drug or vaccine-based therapies. In other apicomplexans, cleavage of the transmembrane domain of adhesins by the serine rhomboid proteinase ROM4 is required for successful completion of invasion. In this study, we record and classify the rhomboid repertoire encoded in the genomes of 10 piroplasmid species pertaining to the lineages Babesia sensu stricto (s.s., Clade VI), Theileria sensu stricto (Clade IV), Theileria equi (Clade IV), Cytauxzoon felis (Clade IIIb) and Babesia microti (Clade I), as defined by Schnittger et al. (2012). Fifty-six piroplasmid rhomboid-like proteins were assigned by phylogenetic analysis and bidirectional best hit to the ROM4, ROM6, ROM7 or ROM8 groups, and their crucial motifs for conformation and function were identified. Forty-four of these rhomboids had either been incorrectly classified or misannotated. Babesia s.s. encode five or three ROM4 proteinase paralogs, whereas the remaining piroplasmids encode two ROM4 paralogs. All piroplasmids encode a single ROM6, ROM7 and ROM8. Thus, an increased paralog number of ROM4 is the only feature distinguishing Babesia s.s. from other piroplasmid lineages. Piroplasmid ROM6 is related to the mammalian mitochondrial rhomboid and, accordingly, N-terminal mitochondrial targeting signal sequences was found in some cases. ROM6 is the only rhomboid encoded by piroplasmids that is ubiquitous in other organisms. ROM8 represents a pseudoproteinase that is highly conserved between studied piroplasmids, suggesting that it is important in regulatory functions. ROM4, ROM6, ROM7 and ROM8 are exclusively present in Aconoidasida, which comprises piroplasmids and Plasmodium, suggesting a relevant functional role in erythrocyte invasion. The correct classification and designation of piroplasmid rhomboids presented in this study facilitates an informed choice for future in-depth study of their functions.     

Reconciling gene and genome duplication events: using multiple nuclear gene families to infer the phylogeny of the aquatic plant family Pontederiaceae

Most plant phylogenetic inference has used DNA sequence data from the plastid genome. This genome represents a single genealogical sample with no recombination among genes, potentially limiting the resolution of evolutionary relationships in some contexts. In contrast, nuclear DNA is inherently more difficult to employ for phylogeny reconstruction because major mutational events in the genome, including polyploidization, gene duplication, and gene extinction can result in homologous gene copies that are difficult to identify as orthologs or paralogs. Gene tree parsimony (GTP) can be used to infer the rooted species tree by fitting gene genealogies to species trees while simultaneously minimizing the estimated number of duplications needed to reconcile conflicts among them. Here, we use GTP for five nuclear gene families and a previously published plastid data set to reconstruct the phylogenetic backbone of the aquatic plant family Pontederiaceae. Plastid-based phylogenetic studies strongly supported extensive paraphyly of Eichhornia (one of the four major genera) but also depicted considerable ambiguity concerning the true root placement for the family. Our results indicate that species trees inferred from the nuclear genes (alone and in combination with the plastid data) are highly congruent with gene trees inferred from plastid data alone. Consideration of optimal and suboptimal gene tree reconciliations place the root of the family at (or near) a branch leading to the rare and locally restricted E. meyeri. We also explore methods to incorporate uncertainty in individual gene trees during reconciliation by considering their individual bootstrap profiles and relate inferred excesses of gene duplication events on individual branches to whole-genome duplication events inferred for the same branches. Our study improves understanding of the phylogenetic history of Pontederiaceae and also demonstrates the utility of GTP for phylogenetic analysis.     

Phylogeny reconstruction in the Caesalpinieae grade (Leguminosae) based on duplicated copies of the sucrose synthase gene and plastid markers

The Caesalpinieae grade (Leguminosae) forms a morphologically and ecologically diverse group of mostly tropical tree species with a complex evolutionary history. This grade comprises several distinct lineages, but the exact delimitation of the group relative to subfamily Mimosoideae and other members of subfamily Caesalpinioideae, as well as phylogenetic relationships among the lineages are uncertain. With the aim of better resolving phylogenetic relationships within the Caesalpinieae grade, we investigated the utility of several nuclear markers developed from genomic studies in the Papilionoideae. We cloned and sequenced the low copy nuclear gene sucrose synthase (SUSY) and combined the data with plastid trnL and matK sequences. SUSY has two paralogs in the Caesalpinieae grade and in the Mimosoideae, but occurs as a single copy in all other legumes tested. Bayesian and maximum likelihood phylogenetic analyses suggest the two nuclear markers are congruent with plastid DNA data. The Caesalpinieae grade is divided into four well-supported clades (Cassia, Caesalpinia, Tachigali and Peltophorum clades), a poorly supported clade of Dimorphandra Group genera, and two paraphyletic groups, one with other Dimorphandra Group genera and the other comprising genera previously recognized as the Umtiza clade. A selection analysis of the paralogs, using selection models from PAML, suggests that SUSY genes are subjected to a purifying selection. One of the SUSY paralogs, under slightly stronger positive selection, may be undergoing subfunctionalization. The low copy SUSY gene is useful for phylogeny reconstruction in the Caesalpinieae despite the presence of duplicate copies. This study confirms that the Caesalpinieae grade is an artificial group, and highlights the need for further analyses of lineages at the base of the Mimosoideae.     

Phylogenomic analysis of the hemp family (Cannabaceae) reveals deep cyto-nuclear discordance and provides new insights into generic relationships

Cannabaceae are a relatively small family of angiosperms, but they include several species of huge economic and cultural significance: marijuana or hemp (Cannabis sativa) and hops (Humulus lupulus). Previous phylogenetic studies have clarified the most deep relationships in Cannabaceae, but relationships remain ambiguous among several major lineages. Here, we sampled 82 species representing all genera of Cannabaceae and utilized a new dataset of 90 nuclear genes and 82 chloroplast loci from Hyb-Seq to investigate the phylogenomics of Cannabaceae. Nuclear phylogenetic analyses revealed a robust and consistent backbone for Cannabaceae. We observed nuclear gene-tree conflict at several deep nodes in inferred species trees, also cyto-nuclear discordance concerning the relationship between Gironniera and Lozanella and the relationships among Trema s.l. (including Parasponia), Cannabis + Humulus, and Chaetachme + Pteroceltis. Coalescent simulations and network analyses suggest that observed deep cyto-nuclear discordances were most likely to stem from incomplete lineage sorting (ILS); nuclear gene-tree conflict might be caused by both ILS and gene flow between species. All genera of Cannabaceae were recovered as monophyletic, except for Celtis, which consisted of two distinct clades: Celtis I (including most Celtis species) and Celtis II (including Celtis gomphophylla and Celtis schippii). We suggest that Celtis II should be recognized as the independent genus Sparrea based on both molecular and morphological evidence. Our work provides the most comprehensive and reliable phylogeny to date for Cannabaceae, enabling further exploration of evolutionary patterns across this family and highlighting the necessity of comparing nuclear with chloroplast data to examine the evolutionary history of plant groups.     

Host specificity of avian haemosporidian parasites is unrelated among sister lineages but shows phylogenetic signal across larger clades

Parasites can vary in the number of host species they infect, a trait known as “host specificity”. Here we quantify phylogenetic signal—the tendency for closely related species to resemble each other more than distantly related species—in host specificity of avian haemosporidian parasites (genera Plasmodium, Haemoproteus and Leucocytozoon) using data from MalAvi, the global avian haemosporidian database. We used the genetic data (479 base pairs of cytochrome b) that define parasite lineages to produce genus level phylogenies. Combining host specificity data with those phylogenies revealed significant levels of phylogenetic signal while controlling for sampling effects; phylogenetic signal was higher when the phylogenetic diversity of hosts was taken into account. We then tested for correlations in the host specificity of pairs of sister lineages. Correlations were generally close to zero for all three parasite genera. These results suggest that while the host specificity of parasite sister lineages differ, larger clades may be relatively specialised or generalised.     

Determinants of haemosporidian single- and co-infection risks in western palearctic birds

Understanding the drivers of infection risk helps us to detect the most at-risk species in a community and identify species whose intrinsic characteristics could act as potential reservoirs of pathogens. This knowledge is crucial if we are to predict the emergence and evolution of infectious diseases. To date, most studies have only focused on infections caused by a single parasite, leaving out co-infections. Yet, co-infections are of paramount importance in understanding the ecology and evolution of host-parasite interactions due to the wide range of effects they can have on host fitness and on the evolutionary trajectories of parasites. Here, we used a multinomial Bayesian phylogenetic modelling framework to explore the extent to which bird ecology and phylogeny impact the probability of being infected by one genus (hereafter single infection) or by multiple genera (hereafter co-infection) of haemosporidian parasites. We show that while nesting and migration behaviours influenced both the probability of being single- and co-infected, species position along the slow-fast life-history continuum and geographic range size were only pertinent in explaining variation in co-infection risk. We also found evidence for a phylogenetic conservatism regarding both single- and co-infections, indicating that phylogenetically related bird species tend to have similar infection patterns. This phylogenetic signal was four times stronger for co-infections than for single infections, suggesting that co-infections may act as a stronger selective pressure than single infections. Overall, our study underscores the combined influence of hosts’ evolutionary history and attributes in determining infection risk in avian host communities. These results also suggest that co-infection risk might be under stronger deterministic control than single infection risk, potentially paving the way toward a better understanding of the emergence and evolution of infectious diseases.     

Molecular Characterization of Gregarines from Sand Flies (Diptera: Psychodidae) and Description of Psychodiella n. g. (Apicomplexa: Gregarinida)

ABSTRACT. Sand fly and mosquito gregarines have been lumped for a long time in the single genus Ascogregarina and on the basis of their morphological characters and the lack of merogony been placed into the eugregarine family Lecudinidae. Phylogenetic analyses performed in this study clearly demonstrated paraphyly of the current genus Ascogregarina and revealed disparate phylogenetic positions of gregarines parasitizing mosquitoes and gregarines retrieved from sand flies. Therefore, we reclassified the genus Ascogregarina and created a new genus Psychodiella to accommodate gregarines from sand flies. The genus Psychodiella is distinguished from all other related gregarine genera by the characteristic localization of oocysts in accessory glands of female hosts, distinctive nucleotide sequences of the small subunit rDNA, and host specificity to flies belonging to the subfamily Phlebotominae. The genus comprises three described species: the type species for the new genus— Psychodiella chagasi ( Adler and Mayrink 1961 ) n. comb., Psychodiella mackiei ( Shortt and Swaminath 1927 ) n. comb., and Psychodiella saraviae ( Ostrovska, Warburg, and Montoya-Lerma 1990 ) n. comb. Its creation is additionally supported by sequencing data from other gregarine species originating from the sand fly Phlebotomus sergenti . In the evolutionary context, both genera of gregarines from mosquitoes ( Ascogregarina ) and sand flies ( Psychodiella ) have a close relationship to neogregarines; the genera represent clades distinct from the other previously sequenced gregarines.     

Architecture of an antagonistic tree/fungus network: the asymmetric influence of past evolutionary history

Background

Compartmentalization and nestedness are common patterns in ecological networks. The aim of this study was to elucidate some of the processes shaping these patterns in a well resolved network of host/pathogen interactions.

Methology/Principal Findings

Based on a long-term (1972–2005) survey of forest health at the regional scale (all French forests; 15 million ha), we uncovered an almost fully connected network of 51 tree taxa and 157 parasitic fungal species. Our analyses revealed that the compartmentalization of the network maps out the ancient evolutionary history of seed plants, but not the ancient evolutionary history of fungal species. The very early divergence of the major fungal phyla may account for this asymmetric influence of past evolutionary history. Unlike compartmentalization, nestedness did not reflect any consistent phylogenetic signal. Instead, it seemed to reflect the ecological features of the current species, such as the relative abundance of tree species and the life-history strategies of fungal pathogens. We discussed how the evolution of host range in fungal species may account for the observed nested patterns.

Conclusion/Significance

Overall, our analyses emphasized how the current complexity of ecological networks results from the diversification of the species and their interactions over evolutionary times. They confirmed that the current architecture of ecological networks is not only dependant on recent ecological processes.     

Community-wide germination strategies in an alpine meadow on the eastern Qinghai-Tibet plateau: phylogenetic and life-history correlates

In this study, we built up a database of 633 species (48 families, 205 genera) from an alpine meadow on the eastern Qinghai-Tibet plateau. Our objective was to assess the effects of phylogenetic and life-history (life form, perenniality, seed size, dispersal strategy and period) background on the community-wide germination strategies. We found that the seeds of shrubs, perennials, and well-dispersed plants, and the smaller seeds germinated more and comparatively earlier. In one-way ANOVAs, phylogenetic groups explained 12% of the variance in GT (mean germination time for all seeds germinated of each species); life-history attributes, such as seed size, dispersal strategy, perenniality and life form explained 10%, 7%, 5%, and 1% respectively, and dispersal period had no significant effect on GT. Multifactorial ANOVAs revealed that the three major factors contributing to differences in GT were phylogenetic relatedness, seed size and dispersal strategy (explained 4%, 5% and 4% of the interspecific variation independently, respectively). Thus, seeds germination strategies were significantly correlated with phylogenetic and life-history relatedness. In addition, phylogenetic relatedness had close associations and interactions with seed size and dispersal strategy. Then, we think phylogeny and life-history attributes could not be considered mutual exclusively. Seed germination, like any other trait, is shaped by the natural history of the species and by the evolutionary history of the lineage. And a large percentage of the variance remained unexplained by our model, which suggested important selective factors or parameters may have been left out of this analysis. Electronic Supplementary Material The online version of this article (doi:) contains supplementary material, which is available to authorized users.