A Cladistic Analysis of Pseudocoelomate (Aschelminth) Morphology

Wallace, Robert L.; Ricci, Claudia; Melone, Giulio

doi:10.2307/3227041

Cited by 104 publications

(61 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Further, it is because they lack the capacity to make such models that they are unable to do a variety of tasks that vertebrates and insects handle with ease. As a group, nematodes may have evolved a simplified body plan and nervous system as a consequence of evolving to exploit very stable environments or a parasitic existence (126,127). In such environments, very simple behavioral control systems are sufficient.…”

Section: Beyond Insectsmentioning

confidence: 99%

What insects can tell us about the origins of consciousness

Barron

Klein

2016

Proc. Natl. Acad. Sci. U.S.A.

258

183

View full text Add to dashboard Cite

How, why, and when consciousness evolved remain hotly debated topics. Addressing these issues requires considering the distribution of consciousness across the animal phylogenetic tree. Here we propose that at least one invertebrate clade, the insects, has a capacity for the most basic aspect of consciousness: subjective experience. In vertebrates the capacity for subjective experience is supported by integrated structures in the midbrain that create a neural simulation of the state of the mobile animal in space. This integrated and egocentric representation of the world from the animal's perspective is sufficient for subjective experience. Structures in the insect brain perform analogous functions. Therefore, we argue the insect brain also supports a capacity for subjective experience. In both vertebrates and insects this form of behavioral control system evolved as an efficient solution to basic problems of sensory reafference and true navigation. The brain structures that support subjective experience in vertebrates and insects are very different from each other, but in both cases they are basal to each clade. Hence we propose the origins of subjective experience can be traced to the Cambrian. subjective experience | primary consciousness | vertebrate midbrain | central complex

show abstract

Section: Beyond Insectsmentioning

confidence: 99%

What insects can tell us about the origins of consciousness

Barron

Klein

2016

Proc. Natl. Acad. Sci. U.S.A.

258

183

View full text Add to dashboard Cite

show abstract

“…Fluid-filled cavities of the so-called "pseucoelomates" and specially the coelomic cavities of the coelomates, lined by a mesodermal epithelium, were the first structures which allowed for a better diffusion of these substances ( Figure 1A). We are aware that coeloms probably appeared through different mechanisms in protostomozoans and deuterostomozoans, and it is possible that many "pseudocoelomate" taxa derive from coelomate ancestors that have lost the coelomic lining (Wallace et al, 1996). Anyway, the existence of a cavity around the gut and the main viscerae, irrespectively of its origin, contributed to the supply of nutrients to the organs and allowed for larger body sizes.…”

Section: A Common Coelomic Origin For Animal Heartsmentioning

confidence: 99%

Building the vertebrate heart - an evolutionary approach to cardiac development

2009

View full text Add to dashboard Cite

The vertebrate heart is unique among the blood pumps described in metazoans. In contrast to the myoepithelial tubes found in most animal phyla, the vertebrate heart is made up of multilayered myocardial cells surrounded by connective tissue derived from epicardium and endocardium, and endowed with complex valvular, coronary vessel and conduction systems. Despite these profound differences, a common genetic program seems to underlie the specification and differentiation of all the cardiac tissues. In this article, we will review the similarities in the transcriptional networks and signalling mechanisms regulating cardiac development in different animals, as well as the origin of the main differences existing between vertebrate and invertebrate hearts. We will pay special attention to the hypotheses concerning the evolutionary origin of the endothelium and the epicardium from ancestral blood cells and pronephric progenitors, respectively. We can summarize the transition between the invertebrate and the vertebrate heart as the result of the thickening of the primarily myoepithelial cardiac tube which was concomitant with: 1) an inner lining by an endothelium with the ability to transform into mesenchyme; 2) an outer lining derived from an ancestral pronephric glomerular primordium with vasculogenic potential; 3) a neural crest cell population which reaches the heart from the pharyngeal region; 4) the incorporation of new myocardium at both ends from a second heart field and 5) the formation of specialized chambers. The complex interactions between all these elements originated an exceptionally powerful blood pump which allowed vertebrates to reach their characteristically large size and activity.

show abstract

“…It is long acknowledged that Acanthocephala and Rotifera are closely related to each other (Lorenzen 1985, Nielsen 1995, Wallace et al 1996, forming the clade of Syndermata (Ahlrichs 1997(Ahlrichs , 1998=Trochata;Cavalier-Smith 1998a). Monophyly of the Syndermata (Fig.…”

Section: Acanthocephala and Seisonmentioning

confidence: 99%

The interrelationships of metazoan parasites: a review of phylum- and higher-level hypotheses from recent morphological and molecular phylogenetic analyses

Zrzavý¹

2001

FOLIA PARASIT

View full text Add to dashboard Cite

Abstract. Phylogeny of seven groups of metazoan parasitic groups is reviewed, based on both morphological and molecular data. The Myxozoa (=Malacosporea + Myxosporea) are most probably related to the egg-parasitic cnidarian Polypodium (Hydrozoa?: Polypodiozoa); the other phylogenetic hypotheses are discussed and the possible non-monophyly of the Cnidaria (with the Polypodiozoa-Myxozoa clade closest to the Triploblastica) is suggested. The Mesozoa is a monophyletic group, possibly closely related to the (monophyletic) Acoelomorpha; whether the Acoelomorpha and Mesozoa represent the basalmost triploblast clade(s) or a derived platyhelminth subclade may depend on rooting the tree of the Triploblastica. Position of the monophyletic Neodermata (=Trematoda + Cercomeromorpha) within the rhabditophoran flatworms is discussed, with two major alternative hypotheses about the neodermatan sister-group relationships (viz., the "neoophoran" and "revertospermatan"). The Myzostomida are not annelids but belong among the Platyzoa, possibly to the clade of animals with anterior sperm flagella (=Prosomastigozoa). The Acanthocephala represent derived syndermates ("rotifers"), possibly related to Seison (the name Pararotatoria comb. n. is proposed for Seisonida + Acanthocephala). The crustacean origin of the Pentastomida based on spermatological and molecular evidence (Pentastomida + Branchiura = Ichthyostraca) is confronted with palaeontological views favouring the pre-arthropod derivation of the pentastomids. Phylogenetic position of the nematodes within the Ecdysozoa and evolution of nematode parasitism are discussed, and the lack of relevant information about the enigmatic ectoproctan parasite Buddenbrockia is emphasised.At present, the metazoan relationships are becoming clearer as phylogenetic techniques are applied to morphological and molecular characters, the molecular data grow exponentially, and the "morphological" (i.e., non-sequence) information is refined by using ultrastructural and biochemical methods. In the present paper, recent contributions concerning the phylogenetic position of major parasitic animal groups are discussed. Seven taxa were selected: two "pseudo-protist" groups that evidently belong to the Metazoa and represent the most simplified multicellular animals (Myxozoa, Mesozoa), two traditional metazoan phyla that are now regarded as modified parasitic representatives of more comprehensive groups (Acanthocephala, Pentastomida), one parasitic "annelid" subgroup recently elevated to a phyletic level, unrelated to the Annelida (Myzostomida), and two major parasitic groups whose sister-group relationships and evolution of host-parasite relationships are recently becoming elucidated (Neodermata, Nematoida).This paper is about trees. It should be emphasised here that a tree (cladogram, maximum likelihood tree, distance tree) is not (or should not be) a graphical presentation of author's personal opinion about the course of evolution. The tree represents a series of hypotheses about the character homology (whet...

show abstract

A Cladistic Analysis of Pseudocoelomate (Aschelminth) Morphology

Cited by 104 publications

References 32 publications

What insects can tell us about the origins of consciousness

What insects can tell us about the origins of consciousness

Building the vertebrate heart - an evolutionary approach to cardiac development

The interrelationships of metazoan parasites: a review of phylum- and higher-level hypotheses from recent morphological and molecular phylogenetic analyses

Contact Info

Product

Resources

About