scholarly journals The Integrative Approach to Inferring Homology: Morphology and Development Combined

Author(s):  
Arsham Nejad Kourki

Reconstructing ancestral species is a challenging endeavour: fossils are often scarce or enigmatic, and inferring ancestral characters based on novel molecular approaches (e.g. comparative genomics or developmental genetics) has long been controversial. A key philosophical challenge pertinent at present is the lack of a theoretical framework capable of evaluating inferences of homology made through integration of multiple kinds of evidence (e.g. molecular, developmental, or morphological). Here, I present just such a framework. I start with a brief history and critical assessment of attempts at inferring morphological homology through developmental genetics. I then bring attention to a recent model of homology, namely Character Identity Mechanisms (DiFrisco, Love, & Wagner, 2020), intended partly to elucidate the relationships between morphological characters, developmental genetics, and homology. I utilise and build on this model to construct the evaluative framework mentioned above, which judges the epistemic value of evidence of each kind in each particular case based on three proposed criteria: effectiveness, admissibility, and informativity, as well as providing a generalised guideline on how it can be scientifically operationalised. I then point out the evolution of the eumetazoan body plan as a case in point where the application of this framework can yield satisfactory results, both empirically and conceptually. I will conclude with a discussion on some potential implications for more general philosophy of biology and philosophy of science, especially surrounding evidential integration, models and explanation, and reductionism.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Edoardo Massa ◽  
Roberto Guidetti ◽  
Michele Cesari ◽  
Lorena Rebecchi ◽  
K. Ingemar Jönsson

AbstractKristianstads Vattenrike Biosphere Reserve [KVBR] is a UNESCO designated area of Sweden possessing high biological value. Although several studies on tardigrades inhabiting Sweden have been performed, the KVBR area has been neglected. The current study investigates the tardigrade fauna of five areas of the biosphere reserve and includes 34 samples of different substrates analysed quantitatively and qualitatively. In total, 33 species of tardigrades were found in the samples, including 22 new records for the Skåne region, 15 new records for Sweden, and four species new to science. Mesobiotus emiliae sp. nov., Xerobiotus gretae sp. nov., Itaquascon magnussoni sp. nov., and Thulinius gustavi sp. nov. were described with an integrative approach (when possible) using morphological characters (light, electron scanning, and confocal laser scanning microscopies) and molecular markers (ITS2, 18S, 28S, cox1). A new protocol to increase morphological data was developed recovering mounted specimens within old slides for SEM analysis. Emended diagnoses for the genus Itaquascon and the transfer of Platicrista itaquasconoide to the genus Meplitumen are proposed. This study enriches the knowledge of the tardigrade biodiversity both within the KVBR and in Sweden and contributes to the rapidly increasing number of tardigrade species reported worldwide. The 33 species identified in the KVBR area represents 28% of all water bear species found in Sweden so far. The restricted study areas and limited number of samples collected suggests that the KVBR is very rich of tardigrades.


Zootaxa ◽  
2021 ◽  
Vol 4926 (3) ◽  
pp. 401-416
Author(s):  
MOHAMMAD HUSSAIN FALAHZADAH ◽  
EBRAHIM SHOKOOHI ◽  
GHOLAM HOSSEIN MORAVEJ ◽  
PHATU WILLIAM MASHELA ◽  
ABDUL KHALID MADADI ◽  
...  

Several soil samples from different habitats in Badakhshan province of Afghanistan were collected to isolate and characterize bacteria feeding nematodes. The Galleria mellonella-baiting method was used for the isolation of the Afghan insect-associated nematodes. The nematodes were studied using morphological and morphometric data. The Oscheius specimen was characterized by a longer body (630–820 µm) and shorter pharynx (125–145 µm), whereas other morphological characters were not unusual. The Diploscapter specimen had an annulated cuticle, with lip region width 1.5 times shorter than the stoma, and had separated pharyngeal corpus from the isthmus and vulva located in the middle of the body. The molecular data were derived using three loci; 18S, 28S (D2/D3 segment), and ITS rRNA region, which were utilized to measure the genetic distance. The phylogenetic analysis was conducted to reconstruct the relationship tree. Both morphological and molecular approaches confirmed the identity of nematode isolates as Oscheius tipulae and Diploscapter coronatus. This is the first report of insect-associated nematodes from the soil of Afghanistan. Both species were capable of infecting and killing G. mellonella larvae in less than 96 h. 


Zootaxa ◽  
2017 ◽  
Vol 4311 (3) ◽  
pp. 301 ◽  
Author(s):  
FERNANDA AZEVEDO ◽  
ANDRÉ PADUA ◽  
FERNANDO MORAES ◽  
ANDRÉ ROSSI ◽  
GUILHERME MURICY ◽  
...  

Despite the enormous economic, scientific and strategic value of the Brazilian oceanic and mid-shelf islands (BOMIs), the biological communities of these islands are still poorly known. An example is their fauna of calcareous sponges (Porifera: Calcarea), with only six species described up to date. In the present study, we analysed the Calcinean sponges from the mid-shelf Abrolhos Archipelago and four of the five Brazilian oceanic islands (São Pedro e São Paulo Archipelago, Fernando de Noronha Archipelago, Rocas Atoll, and Trindade Island), using both morphological and molecular approaches for taxonomy. Fourteen species were found, of which 12 are new to science: Arturia trindadensis sp. nov., Borojevia tenuispinata sp. nov., B. trispinata sp. nov., Clathrina insularis sp. nov., C. lutea sp. nov., C. mutabilis sp. nov., C. zelinhae sp. nov., Ernstia citrea sp. nov., E. multispiculata sp. nov., E. rocasensis sp. nov., E. sanctipauli sp. nov., and E. solaris sp. nov. These results raised in 63% the species richness of calcareous sponges from the BOMIs. Clathrina aurea and Leucetta floridana were recollected and the former had its geographical distribution expanded. The molecular tree obtained confirmed the morphological identifications and allowed a discussion about the evolution of morphological characters, and the usefulness of some of those characters in the taxonomy of Calcinea. 


Author(s):  
Michael D. Hamlin

Business education is education for practice and thus, requires a systematic and integrative approach that will guide students toward becoming reflective practitioners. Case-based education is an important tool that can provide the educational experiences that produce effective practitioners but only if its use is guided by a sound theoretical and research based framework. Research and theory from the learning sciences can guide case-based instructional practices. This chapter will provide a framework for the design of case-based instruction that incorporates teaching and learning affordances derived from the theory of situated learning and cognition. If the educational goal is to produce business practitioners with the skills and knowledge necessary to operate successfully in today's global business environment, business education needs to be prepared to incorporate theoretical perspectives derived from learning sciences research into case-based education.


2021 ◽  
Vol 17 (1) ◽  
pp. 35
Author(s):  
Wartono Wartono

<p>Chili (Capsicum annuum L.) is a vegetable commodity with high economic value which is widely cultivated by farmers in Indonesia. One of the obstacles faced in chili cultivation is stem rot disease. This study aimed to identify the pathogens that caused stem rot in chili plants obtained from one location in Sindangjaya Village, Cipanas District, Cianjur Regency, West Java Province based on morphological and molecular analyses. Pathogen identification was performed with morphological and molecular approaches. The morphological characters observed included colony shape, sporangium diameter, and mating type. The pathogenicity of the isolates was assayed by inoculating chili stems aged 40 days. Molecular identification was carried out using two pairs of primers for ITS regions and TEF-1 gene. Based on the results of morphological and molecular identification, as well as pathogenicity tests, it was confirmed that Phytophthora capsici pathogen was the causal agent of stem rot in chili plants collected from Sindangjaya Village. Further study is needed to determine the spread of the disease, damage, and yield loss caused by stem rot disease, as well as how to prevent and control the disease.</p>


2018 ◽  
pp. 563-590
Author(s):  
Michael D. Hamlin

Business education is education for practice and thus, requires a systematic and integrative approach that will guide students toward becoming reflective practitioners. Case-based education is an important tool that can provide the educational experiences that produce effective practitioners but only if its use is guided by a sound theoretical and research based framework. Research and theory from the learning sciences can guide case-based instructional practices. This chapter will provide a framework for the design of case-based instruction that incorporates teaching and learning affordances derived from the theory of situated learning and cognition. If the educational goal is to produce business practitioners with the skills and knowledge necessary to operate successfully in today's global business environment, business education needs to be prepared to incorporate theoretical perspectives derived from learning sciences research into case-based education.


Author(s):  
Michael D. Hamlin

Adult learners tend to have specific educational goals, are more career-focused, task and intrinsically motivated, and more concerned about application of knowledge. Most adult learners are employed or attending school to advance their careers, so ideally, adult education should comprise educational activities, at least in part, focused on improving knowledge and skills relevant to the workplace. This requires a systematic and integrative approach that will guide students toward becoming reflective practitioners. Case-based education is an important tool that can provide the educational experiences that produce effective practitioners but only if its use is guided by a sound theoretical and research-based framework. This chapter will provide a framework for the design of case-based instruction that incorporates teaching and learning affordances derived from the theory of situated learning and cognition.


2016 ◽  
Vol 91 (3) ◽  
pp. 360-370 ◽  
Author(s):  
D.H. Morais ◽  
A. Aguiar ◽  
M.I. Müller ◽  
R.B. Narciso ◽  
L.A.F. da Silva ◽  
...  

AbstractSerpentirhabdias viperidicus n. sp. (Nematoda: Rhabdiasidae) is described from the lungs of the ‘Brazilian lancehead’ Bothrops moojeni (Hoge, 1966) from the savannah in São Paulo State, Brazil. The new species is the eighth species of Serpentirhabdias described in the Neotropical region, and differs from other species mainly by a combination of characters: lips slightly notable, presence of fine striations at posterior ends, presence of two parallel lines with intercalated pores, a pore-shaped phasmid situated at the level of the anal aperture and another two in the posterior half of the tail. It is the first species of Serpentirhabdias reported in this snake host and the second species of this genus found parasitizing South American viperidian snakes. Molecular phylogenetic analysis using ribosomal (ITS and 28S partial) genes confirms Serpentirhabdias viperidicus n. sp. as a new species that clustered in the Serpentirhabdias clade, sister taxon to Serpentirhabdias fuscovenosa and Serpentirhabdias elaphe. This is the first description of Serpentirhabdias species from Brazil using molecular approaches and morphological characters to confirm the monophyly of this recent genus.


Phytotaxa ◽  
2020 ◽  
Vol 439 (1) ◽  
pp. 39-55
Author(s):  
EDILENE MARIA DOS SANTOS PESTANA ◽  
GOIA DE MATTOS LYRA ◽  
GABRIEL DO NASCIMENTO SANTOS ◽  
CIBELE CONCEIÇÃO DOS SANTOS ◽  
VALÉRIA CASSANO ◽  
...  

Peyssonneliaceae represents a monophyletic clade of red encrusting algae classified Peyssonneliales. Molecular analyses have been important for revealing unknown diversity in this family, which includes small, cryptic organisms, frequently distinguished solely by discrete anatomical characters. Brazil however, remains virtually unknown. To assess this diversity, phylogenetic and barcoding analyses using rbcL, COI-5P and SSU data, as well as morpho-anatomical analyses were performed. Here we report the first occurrence of two genera on the Brazilian coast: Ramicrusta and Incendia, and describe three new species: Ramicrusta fujiiana sp. nov., Ramicrusta paradoxa sp. nov. and Incendia yoneshigueana sp. nov. Ramicrusta was resolved as a monophyletic clade in the three reconstructed phylogenies, and had congruent topologies. In the rbcL phylogeny, Ramicrusta fujiiana formed a well-supported clade sister to a well-supported clade including R. aranea (Vanuatu, type locality) and R. textilis (Jamaica, type locality). Morphological characters of R. paradoxa are not in agreement with the original description of the genus. Therefore, we present an updated and broader concept of Ramicrusta. Incendia was resolved as a monophyletic clade with full support for rbcL. Incendia yoneshigueana is in a sister relationship with I. glabra (Vanuatu, type locality). This study extends the distributions of Ramicrusta and Incendia, proposes three new species, and confirms the effectiveness of rbcL, COI-5P and SSU in inferring phylogenetic relationships and delimiting species in the Peyssonneliales. The integrative approach established clear taxonomic concepts for the studied genera and species, and identified useful characters for genera delimitation in Peyssonneliaceae.


2015 ◽  
Vol 105 (12) ◽  
pp. 1555-1567 ◽  
Author(s):  
X. Q. Zhu ◽  
C. L. Xiao

Fruit rot caused by Alternaria spp. is one of the most important factors affecting the postharvest quality and shelf life of blueberry fruit. The aims of this study were to characterize Alternaria isolates using morphological and molecular approaches and test their pathogenicity to blueberry fruit. Alternaria spp. isolates were collected from decayed blueberry fruit in the Central Valley of California during 2012 and 2013. In total, 283 isolates were obtained and five species of Alternaria, including Alternaria alternata, A. tenuissima, A. arborescens, A. infectoria, and A. rosae, were identified based on DNA sequences of the plasma membrane ATPase, Alt a1 and Calmodulin gene regions in combination with morphological characters of the culture and sporulation. Of the 283 isolates, 61.5% were identified as A. alternata, 32.9% were A. arborescens, 5.0% were A. tenuissima, and only one isolate of A. infectoria and one isolate of A. rosae were found. These fungi were able to grow at temperatures from 0 to 35°C, and mycelial growth was arrested at 40°C. Optimal radial growth occurred between 20 to 30°C. Pathogenicity tests showed that all five Alternaria spp. were pathogenic on blueberry fruit at 0, 4, and 20°C, with A. alternata, A. arborescens, and A. tenuissima being the most virulent species, followed by A. infectoria and A. rosae. Previously A. tenuissima has been reported to be the primary cause of Alternaria fruit rot of blueberry worldwide. Our results indicated that the species composition of Alternaria responsible for Alternaria fruit rot in blueberry can be dependent on geographical region. A. alternata, A. arborescens, A. infectoria, and A. rosae are reported for the first time on blueberry in California. This is also the first report of A. infectoria and A. rosae infecting blueberry fruit.


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