Francisco Vergara-Silva

Instituto de Biología, Universidad Nacional Autónoma de México · Jardín Botánico

Background and Aims The size and shape of reproductive structures is especially relevant in evolution because these characters are directly related to the capacity of pollination and seed dispersal, a process that plays a basic role in evolutionary patterns. The evolutionary trajectories of reproductive phenotypes in gymnosperms have received speci...

Taxonomic data is essential to advance the discovery and description of biodiversity, as well as the study of evolutionary processes. Emerging large-scale datasets and new methods of analysis have provided different approaches to describe biodiversity. Here, we present a review of the taxonomic history in Cycadales including an analysis of historic...

Debido a su toxicidad, el camotillo es muy temido en algunas comunidades; sin embargo, esta cícada no es tan dañina como se piensa, incluso puede tener algunos beneficios. Durante una reciente exploración botánica en Honduras registramos una historia que forma parte del acervo cultural de las comunidades locales asentadas en el área de distribución...

Transdisciplinary research knits together knowledge from diverse epistemic communities in addressing social-environmental challenges, such as biodiversity loss, climate crises, food insecurity, and public health. This paper reflects on the roles of philosophy of science in transdisciplinary research while focusing on Indigenous and other subjugated...

Evo-devo is often thought of as being the study of which genes underlie which phenotypes. However, evo-devo is much more than this, especially in plant science. In leaf scars along stems, cell changes across wood growth rings, or flowers along inflorescences, plants trace a record of their own development. Plant morpho evo-devo provides data that g...

Comprender que los organismos multicelulares no son entes pasivos es esencial, por una parte, para ampliar nuestro entendimiento sobre la evolución de las especies y, por otra, para esclarecer cómo percibimos e interactuamos en el mundo. Lo anterior se debe a que, a través de múltiples procesos y mecanismos ontogenéticos y filogenéticos, los organi...

The ethics of the scientific study of Ancestors has long been debated by archaeologists, bioanthropologists, and, more recently, ancient DNA (aDNA) researchers. This article responds to the article “Ethics of DNA research on human remains: five globally applicable guidelines” published in 2021 in Nature by a large group of aDNA researchers and coll...

Multidisciplinary taxonomic studies have enhanced the delimitation of species within complex taxonomic groups. In the cycad genus Ceratozamia, the taxonomy is still not fully resolved for the several species complexes that have been proposed. Five Ceratozamia species occur in geographic proximity in the Soconusco region of southwestern Mexico. Beca...

How biology should figure in Anthropocene studies, hitherto stemming from Earth sciences and a broad constellation of human and social sciences, is still an unsettled issue among scholars. Here, we contribute with a historiographically-informed perspective on the specific role that ‘biological theory’ has played in past rounds of reflection on the...

Ceratozamia (Zamiaceae, Cycadales), is a member one of the most endangered seed plant groups. Species of Ceratozamia grow from near sea level up to 2,100 meters in Mexico and Mesoamerica. We present a modern taxonomic treatment of Ceratozamia , based on fieldwork combined with detailed study of herbarium specimens in and from Mexico and Central Ame...

The reproductive phenology in plants consists of successive life cycle phases leading to reproductive success. In seed plants, cycads and other dioecious groups have complex reproductive systems, where individuals require synchronizations among two sexes and populations of the same species. Here, we analyzed phenology between populations of three g...

Ceratozamia is a neotropical genus in the Cycadales that is particularly diverse in Mexico. In this genus, most species are endemic to Mexico and most of these species have a restricted distribution pattern. We propose and describe a new species from western Oaxaca State, Mexico, which was previously subsumed under the concept of C. robusta. The ci...

Ceratozamia, a genus of Zamiaceae, is one of the most species rich genera of gymnosperms in Mexico with a high level of species endemism. Over the last two decades, their known diversity has increased considerably because of extensive field work. Recently, 16 new species were described as a result of revision of species complexes and new exploratio...

Echeveria kristenii is described as a new species from Sierra Azul, Mezquital, Durango. The new species belongs to a sub-group of northwestern Mexican taxa within ser. Gibbiflorae. Within the series it is most similar to E. dactylifera and E. novogaliciana in its acaulescent habit, sessile, farinaceous and somewhat narrowed leaves, paniculate inflo...

As an evolutionary lineage cycads are rare, and the extinction risk is high for many species. The genus Ceratozamia , one of the most diverse in Mexico, is experiencing drastic reductions of its habitat. Ceratozamia is widely distributed along the Sierra Madre Oriental, a complex mountain range, in a region characterized by high ecological and cult...

Ceratozamia is a genus of cycads occurring in eastern Mexico and Central America. In this study, we describe a new species from the Pacific region of Mexico in Guerrero state. This locality represents the most northwestern Mexico distribution for the genus. We focus the comparison of this species with the most geographically proximate and phenotypi...

Background: Most reports of domesticated plants that involve a domestication gradient or inter-specific hybridization in Mexico have focused on those used as food. This study provides knowledge about these processes in two aromatic medicinal plants, Agastache mexicana (Lamiaceae) and A. m. subsp. xolocotziana, widely used in Mexican traditional me...

Research on urban systems has documented the contributions of cities as sites where insect pollinators undergo their life cycles, contributing to the reproduction of many groups of plants. However, reports of plants whose reproduction is assisted by specialist pollinators under conditions prevalent in cities are scarce. Cycads and insect pollinator...

Pachyphytum viscidum (Crassulaceae: Saxifragales) is described as a new species to science. The specimens analyzed come from the Sierra de Santa Bárbara, Guanajuato, Mexico. Some morphological diagnostic characters for the new species are: sticky stems and leaves; dark green leaves; absence of wax on all their organs; and pale pink flowers. The new...

Biologists and philosophers of science have recently called for an extension of evolutionary theory. This so-called ‘extended evolutionary synthesis’ (EES) seeks to integrate developmental processes, extra-genetic forms of inheritance, and niche construction into evolutionary theory in a central way. While there is often agreement in evolutionary b...

Mexico is considered as diversification and endemism center of the genus Echeveria. Previous tree inference studies have shown the genus to be non-monophyletic in relation to other genera, but sampling for Echeveria has been poor, and has not allowed to understand the relationships within the genus. In this work, Bayesian and maximum likelihood phy...

Here we present a circumscription with qualitative and quantitative morphological comparison including all populations of Zamia along the coastal plain of Pacific Mexico. We recognize four species in this area: Z. paucijuga, Z. herrerae, Z. spartea and the new species, Z. stenophyllidia is described as new cycad species from Michoacán, Mexico. This...

Ethnobiology is an interdisciplinary field at the intersection of biological and social sciences that studies knowledge systems and practices of Indigenous, traditional, and other local communities. The complexity of biological expertise beyond academia raises both theoretical and normative questions about knowledge diversity in biological and envi...

Biologists energetically debate terminology in ecology and evolution, but rarely discuss general strategies for resolving these debates. We suggest focusing on metaphors, arguing that, rather than looking down on metaphors, biologists should embrace these terms as the powerful tools they are. Like any powerful tool, metaphors need to be used mindfu...

Echeveria xochipalensis, from the state of Guerrero, Mexico, is described as a new species to science. It is related to species of ser. Gibbiflorae, particularly to both E. fulgens varieties, from which it is distinguished by its green to lilac-gray spatulate leaves, although they commonly are coppery tinged; the leaves are rigid and with entire ma...

Echeveria michihuacana (Crassulaceae), a new species for science, is described and illustrated. The new taxon is related to a group of species of Echeveria series Gibbiflorae from western Mexico, including Echeveria dactylifera, Echeveria fulgens, Echeveria patriotica, and particularly the recently published Echeveria pistioides. With the last spec...

The Extended Evolutionary Synthesis (EES) debate is gaining ground in contemporary evolutionary biology. In parallel, a number of philosophical standpoints have emerged in an attempt to clarify what exactly is represented by the EES. For Massimo Pigliucci, we are in the wake of the newest instantiation of a persisting Kuhnian paradigm; in contrast,...

The genus Ceratozamia is revised for the Sierra Madre Oriental in Mexico. This region is one of the biogeographic areas with the greatest diversity of species in this genus. These species are highly variable morphologically and this variability has led to a complex taxonomic history with many synonyms, particularly with reference to C.mexicana . We...

Contemporary evolutionary biology comprises a plural landscape of multiple co-existent conceptual frameworks and strenuous voices that disagree on the nature and scope of evolutionary theory. Since the mid-eighties, some of these conceptual frameworks have denounced the ontologies of the Modern Synthesis and of the updated Standard Theory of Evolut...

According to the integrative taxonomy (IT) framework, delimitation of taxonomic specimens into bona fide species requires the incorporation of multiple sources of biological evidence that jointly perform a role as systematic criteria. Here, we collected a combination of geographic, morphological (qualitative and quantitative), and molecular data se...

Recent collections of Ceratozamia from the Sierra Norte of Puebla, Mexico, point to a new undescribed species, which was previously subsumed under the concept of C. mexicana. Identification of this new species resulted from a review of three associated species: C. mexicana, C. tenuis, and C. delucana. Here we describe Ceratozamia totonacorum and pr...

The vascular cambium is a lateral meristem that produces secondary xylem (i.e., wood) and phloem. Different Cactaceae species develop different types of secondary xylem; however, little is known about the mechanisms underlying wood formation in the Cactaceae. The KNOTTED HOMEOBOX (KNOX) gene family encodes transcription factors that regulate plant...

A new species, from the montane region of Los Tuxtlas (state of Veracruz, Mexico), Ceratozamia subroseophylla, is proposed in accordance with the integrative taxonomy framework and through application of the taxonomic circle rationale. Our identification of this new species is the result of a thorough re-evaluation of four formerly described Cerato...

Famous for its blind cavefish and Darwin's finches, Latin America is home to some of the richest biodiversity hotspots of our planet. The Latin American fauna and flora inspired and captivated naturalists from the nineteenth and twentieth centuries, including such notable pioneers such as Fritz Müller, Florentino Ameghino, and Léon Croizat who made...

Research on traditional ecological knowledge (TEK) in Mexico is linked to geographical regions with the highest levels of biocultural diversity—for instance, Chiapas, Oaxaca, and Yucatán. Long-term historical and ethnographic research in Oaxaca suggests extensive interethnic conflict during precolonial times and subsequent Western interventions in...

This study reports on the socio-demographic and locality factors that influence ethnobiological knowledge in three communities of Zapotec indigenous people of the Isthmus of Tehuantepec, Mexico. It uses local botanical nomenclature as a proxy for general ethnobiological knowledge. In each of these communities (one urban and two rural), 100 adult me...

Methodological controversies are an important but often neglected issue in the philosophy of science. Because experimental results often cannot settle controversies, other elements must be incorporated to debates. We introduce the notion of borrowed epistemic credibility to better understand the role that non-empirical elements play in such cont...

Methodological controversies are an important but often neglected issue in the philosophy of science. Because experimental results often cannot settle controversies, other elements must be incorporated to debates. We introduce the notion of borrowed epistemic credibility to better understand the role that non-empirical elements play in such controv...

We have investigated the phylogeographic structure and demographic history of Zamia paucijuga, based on 120 ITS2 and 117 psbK/I sequences from 13 populations distributed along the entire distribution range of the species. We have detected 15 ITS2 and four psbK/I haplotypes, for a total of 19. The genetic diversity estimated for psbK/I was relativel...

Phylogeography, a relatively new subdicipline of evolutionary biology that attempts to unify the fields of phylogenetics and population biology in an explicit geographical context, has hosted in recent years a highly polarized debate related toon the purported benefits and limitations that qualitative versus quantitative methods might contribute or...

Reproductive organs in seed plants are morphologically divergent and their evolutionary history is often unclear. The mechanisms controlling their development have been extensively studied in angiosperms but are poorly understood in conifers and other gymnosperms. Here, we address the molecular control of seed cone development in N orway spruce, P...

Triuris brevistylis Donn. Sm. (Triuridaceae: Pandanales), a mycoheterotrophic monocotyledon with populations in Mexico and Guatemala, is closely related to Lacandonia schismatica E. Martínez et C. H. Ramos, a triurid species displaying a peculiar “inside-out” arrangement in its reproductive axes. Triuris brevistylis is a polygamodioecious species i...

Dentro de los grupos actuales de espermatofitas, plantas con semilla, las cícadas cuentan con el registro fósil más antiguo. A pesar de ello, su estatus como “fósiles vivientes” ha sido puesto en entredicho recientemente con base en resultados de estudios filogenéticos moleculares. El grupo presenta apomorfías morfológicas vegetativas y posiblement...

With the recent proposal of matK and rbcL as core plant DNA barcoding regions by the Consortium for the Barcoding of Life Plant Working Group, the construction of reference libraries in the botanical DNA barcoding initiative has entered a new phase. However, in a recent DNA barcoding study in the three Mexican genera of the gymnosperm order Cycadal...

The genus Zamia in Megamexico includes 22 described species and one entity in the species dubium category (Z. verschaffeltii). During the last 2 decades, the genus Zamia has received attention in regional floristic treatments and, outstandingly, in a specialized monograph. Besides, some species in the genus have been the focus of several recent cyt...

In this comparative developmental genetics study, we test hypotheses based on fossil and morphological data on reproductive organ morphology and evolution in conifers--specifically, the ovule-bearing organ in Cupressaceae and Taxodiaceae. Genes homologous to the Arabidopsis gene AGAMOUS are expressed in ovuliferous scales of spruces (Picea) through...

The morphological variation among reproductive organs of extant gymnosperms is remarkable, especially among conifers. Several hypotheses concerning morphological homology between various conifer reproductive organs have been put forward, in particular in relation to the pine ovuliferous scale. Here, we use the expression patterns of orthologs of th...

Allozyme diversity and population genetic structure studies were conducted in populations of two Mexican cycad species occurring in adjacent and closely related biogeographic regions. We evaluated if rarity traits in Dioon caputoi, a micro-endemic species, and Dioon merolae, a regional endemic with a wider distribution, influence levels of genetic...

Conifer cones are reproductive structures that are typically of restricted growth and either exclusively pollen-bearing (male) or exclusively ovule-bearing (female). Here, we review two common spontaneous developmental abnormalities of conifer cones: proliferated cones, in which the apex grows vegetatively, and bisexual cones, which possess both ma...

A DNA barcoding study was conducted to determine the optimal combination of loci needed for successful species-level molecular identification in three extant cycad genera—Ceratozamia, Dioon, and Zamia—that occur in Mexico. Based on conclusions of a previous multigene study in representative species of all genera in the Cycadales, we tested the DNA...

The new species Dioon stevensonii, from the Rio Balsas basin spanning the states of Michoacan and Guerrero, Mexico, is described and illustrated. The description of this species implies a recircumscription of the populations of Dioon that constitute the previously characterised D. tomasellii, which also includes populations located in Durango, Naya...

Despite the amount of work that has been produced on the subject over the years, the 'transformation of cladistics' is still a misunderstood episode in the history of comparative biology. Here, I analyze two outstanding, highly contrasting historiographic accounts on the matter, under the perspective of an influential dichotomy in the philosophy of...

Emerging evidence suggests that certain key genes control the branching patterns of flower-bearing axes (i.e. inflorescences) in angiosperms. However, the terminology surrounding inflorescence architecture is heavily typological and suffers from radically divergent definitions of terms that together reduce the value of some recent predictive models...

This special issue of Acta Biotheoretica grows out of a small conference on ''Systematics, Darwinism, and the Philosophy of Science'' held at the Universidad Nacional Autonoma de Mexico (UNAM) in the Fall of 2006. We asked the conference attendees and other experts to submit papers exploring issues emerging around contemporary biological systematic...

A phylogenetic analysis of the monocots was conducted on the basis of nucleotide sequence variation in two genes (atpA, encoded in the mitochondrial genome, and rbcL, encoded in the plastid genome). The taxon sample of 218 angiosperm terminals included 177 monocots and 41 dicots. Among the major results of the analysis are the resolution of a clade...

We have estimated levels of genetic diversity and partitioning in the Mexican endemic cycad species Dioon sonorense, Dioon tomasellii, and Dioon holmgrenii, whose populations are exclusively distributed along the Pacific seaboard. For the three species, the patterns of variation at 19 allozyme loci in a total of 11 populations were evaluated. The a...

The identity of genes causally implicated in the development and evolutionary origin of reproductive characters in gymnosperms is largely unknown. Working within the framework of plant evolutionary developmental biology, here we have cloned, sequenced, performed phylogenetic analyses upon and tested the expression patterns of LEAFY/FLORICAULA and N...

The enigmatic monocotyledon family Triuridaceae is composed of inconspicuous mycoheterotrophs, that have been variously inter- preted. We present here the first report of a thorough floral developmental series for any member of the Triuridaceae. The two known Mexican Triuridaceae species were studied with anatomical sections and scanning electron m...