Morphology (biology)

Morphology is a branch of biology dealing with the study of the form and structure of organisms and their specific structural features.[1]

This includes aspects of the outward appearance (shape, structure, colour, pattern, size), i.e. external morphology (or eidonomy), as well as the form and structure of the internal parts like bones and organs, i.e. internal morphology (or anatomy). This is in contrast to physiology, which deals primarily with function. Morphology is a branch of life science dealing with the study of gross structure of an organism or taxon and its component parts.

Caprella mutica male morphology
Morphology of a male shrimp, Caprella mutica

History

The word "morphology" is from the Ancient Greek μορφή, morphé, meaning "form", and λόγος, lógos, meaning "word, study, research".

While the concept of form in biology, opposed to function, dates back to Aristotle (see Aristotle's biology), the field of morphology was developed by Johann Wolfgang von Goethe (1790) and independently by the German anatomist and physiologist Karl Friedrich Burdach (1800).[2]

Among other important theorists of morphology are Lorenz Oken, Georges Cuvier, Étienne Geoffroy Saint-Hilaire, Richard Owen, Karl Gegenbaur and Ernst Haeckel.[3][4]

In 1830, Cuvier and E.G.Saint-Hilaire engaged in a famous debate, which is said to exemplify the two major deviations in biological thinking at the time – whether animal structure was due to function or evolution.[5]

Divisions of morphology

  • Comparative morphology is analysis of the patterns of the locus of structures within the body plan of an organism, and forms the basis of taxonomical categorization.
  • Functional morphology is the study of the relationship between the structure and function of morphological features.
  • Experimental morphology is the study of the effects of external factors upon the morphology of organisms under experimental conditions, such as the effect of genetic mutation.
  • "Anatomy" is a "branch of morphology that deals with the structure of organisms".[6]
  • Molecular Morphology is a term used in English-speaking countries for describing the structure of compound molecules, such as polymers [7] and ribonucleic acid (RNA).
  • Gross Morphology refers to the collective structures of an organism as a whole as a general description of the form and structure of an organism, taking into account all of its structures without specifying an individual structure.

Morphology and classification

Most taxa differ morphologically from other taxa. Typically, closely related taxa differ much less than more distantly related ones, but there are exceptions to this. Cryptic species are species which look very similar, or perhaps even outwardly identical, but are reproductively isolated. Conversely, sometimes unrelated taxa acquire a similar appearance as a result of convergent evolution or even mimicry. In addition, there can be morphological differences within a species, such as in Apoica flavissima where queens are significantly smaller than workers. A further problem with relying on morphological data is that what may appear, morphologically speaking, to be two distinct species, may in fact be shown by DNA analysis to be a single species. The significance of these differences can be examined through the use of allometric engineering in which one or both species are manipulated to phenocopy the other species.

A step relevant to the evaluation of morphology between traits/features within species, includes an assessment of the terms: homology and homoplasy. Homology between features indicate that those features have been derived from a common ancestor.[8] Alternatively, homoplasy between features describes those that can resemble each other, but derive independently via parallel or convergent evolution.[9]

3D cell morphology: classification

Invention and development of microscopy enable the observation of 3-D cell morphology with both high spatial and temporal resolution. The dynamic processes of these cell morphology which are controlled by a complex system play an important role in varied important biological process, such as immune and invasive responses.[10] [11]

See also

References

  1. ^ "Morphology". Oxford Dictionary. Oxford University Press. Retrieved 2018-02-22.
  2. ^ Mägdefrau, Karl (1992). Geschichte der Botanik [History of Botany] (2 ed.). Jena: Gustav Fischer Verlag. ISBN 3-437-20489-0.
  3. ^ Richards, R. J. (2008). A Brief History of Morphology. In: The Tragic Sense of Life. Ernst Haeckel and the Struggle over Evolutionary Thought. Chicago: University of Chicago Press.
  4. ^ Di Gregorio, M. A. (2005). From Here to Eternity: Ernst Haeckel and Scientific Faith. Gottingen: Vandenhoeck & Ruprecht.
  5. ^ Appel, Toby (1987). The Cuvier-Geoffroy Debate: French Biology in the Decades Before Darwin. New York: Oxford University Press.
  6. ^ "Anatomy – Definition of anatomy by Merriam-Webster". merriam-webster.com.
  7. ^ "Polymer Morphology". ceas.uc.edu/. Retrieved 2010-06-24.
  8. ^ J., Lincoln, Roger (1998). A dictionary of ecology, evolution, and systematics. Boxshall, Geoffrey Allan., Clark, P. F. (2nd ed.). Cambridge: Cambridge University Press. ISBN 052143842X. OCLC 36011744.
  9. ^ Harvey., Pough, F. (2009). Vertebrate life. Janis, Christine M. (Christine Marie), 1950-, Heiser, John B. (8th ed.). San Francisco: Benjamin Cummings. ISBN 0321545761. OCLC 184829042.
  10. ^ A. D. Doyle, R. J. Petrie, M. L. Kutys, and K. M. Yamada, “Dimensions in cell migration,” Curr. Opin. Cell Biol., vol. 25, no. 5, pp. 642–649, 2013.
  11. ^ A. C. Dufour, T. Y. Liu, D. Christel, T. Robin, C. Beryl, T. Roman, G. Nancy, O.H. Alfred, and J. C. Olivo-Marin. "Signal Processing Challenges in Quantitative 3-D Cell Morphology: More than meets the eye." IEEE Signal Processing Magazine, vol. 32, no. 1, pp. 30-40, 2015.

External links

Anatomy

Anatomy (Greek anatomē, "dissection") is the branch of biology concerned with the study of the structure of organisms and their parts. Anatomy is a branch of natural science which deals with the structural organization of living things. It is an old science, having its beginnings in prehistoric times. Anatomy is inherently tied to developmental biology, embryology, comparative anatomy, evolutionary biology, and phylogeny, as these are the processes by which anatomy is generated over immediate (embryology) and long (evolution) timescales. Anatomy and physiology, which study (respectively) the structure and function of organisms and their parts, make a natural pair of related disciplines, and they are often studied together. Human anatomy is one of the essential basic sciences that are applied in medicine.The discipline of anatomy is divided into macroscopic and microscopic anatomy. Macroscopic anatomy, or gross anatomy, is the examination of an animal's body parts using unaided eyesight. Gross anatomy also includes the branch of superficial anatomy. Microscopic anatomy involves the use of optical instruments in the study of the tissues of various structures, known as histology, and also in the study of cells.

The history of anatomy is characterized by a progressive understanding of the functions of the organs and structures of the human body. Methods have also improved dramatically, advancing from the examination of animals by dissection of carcasses and cadavers (corpses) to 20th century medical imaging techniques including X-ray, ultrasound, and magnetic resonance imaging.

Bat flight

Bats are the only mammal capable of true flight. Bats use flight for capturing prey, breeding, avoiding predators, and long-distance migration. Bat wing morphology is often highly specialized to the needs of the species.

Bulletin of Insectology

Bulletin of Insectology (2017 impact factor: 1.088 in entomology category – ISSN 1721-8861) is a scientific journal of entomology and publishes original articles mainly on morphology, biology, behaviour and physiology of insects and other arthropods; control of insects, mites and other arthropod pests with particular reference to biocontrol and integrated pest management.

Cell division orientation

Cell division orientation is the direction along which the new daughter cells are formed. Cell division orientation is important for morphogenesis, cell fate and tissue homeostasis. Abnormalities in the cell division orientation leads to the malformations during development and cancerous tissues. Factors that influence cell division orientation are cell shape, anisotropic localization of specific proteins and mechanical tensions.

Form classification

Form classification is the classification of organisms based on their morphology, which does not necessarily reflect their biological relationships. Form classification, generally restricted to palaeontology, reflects uncertainty; the goal of science is to move "form taxa" to biological taxa whose affinity is known.Form taxonomy is restricted to fossils that preserve too few characters for a conclusive taxonomic definition or assessment of their biological affinity, but whose study is made easier if a binomial name is available by which to identify them. The term "form classification" is preferred to "form taxonomy"; taxonomy suggests that the classification implies a biological affinity, whereas form classification is about giving a name to a group of morphologically-similar organisms that may not be related.A "parataxon" (not to be confused with parataxonomy), or "sciotaxon" (Gr. "shadow taxon"), is a classification based on incomplete data: for instance, the larval stage of an organism that cannot be matched up with an adult. It reflects a paucity of data that makes biological classification impossible. A sciotaxon is defined as a taxon thought to be equivalent to a true taxon (orthotaxon), but whose identity cannot be established because the two candidate taxa are preserved in different ways and thus cannot be compared directly.

Gracility

Gracility is slenderness, the condition of being gracile, which means slender.

It derives from the Latin adjective gracilis (masculine or feminine), or gracile (neuter) which in either form means slender, and when transferred for example to discourse, takes the sense of "without ornament", "simple", or various similar connotations.In his famous "Glossary of Botanic Terms", B. D. Jackson speaks dismissively of an entry in earlier dictionary of A. A. Crozier as follows: Gracilis (Lat.), slender. Crozier has the needless word "gracile". However, his objection would be hard to sustain in current usage; apart from the fact that "gracile" is a natural and convenient term, it is hardly a neologism; the Shorter Oxford English Dictionary gives the source date for that usage as 1623.

In the same entry for Gracile, the Shorter Oxford English Dictionary remarks: Recently misused (through association with grace) for Gracefully slender. This misuse is unfortunate at least, because the terms gracile and grace are completely unrelated: the etymological root of grace is the Latin word gratia from gratus, meaning pleasing and nothing to do with slenderness or thinness.

Hertwig rule

Hertwig's rule or 'long axis rule' states that a cell divides along its long axis. It was introduced by german zoologist Oscar Hertwig in 1884. The rule emphasizes the cell shape to be a default mechanism of spindle apparatus orientation. Hertwig's rule predicts cell division orientation, that is important for tissue architecture, cell fate and morphogenesis.

International Society for Invertebrate Morphology

International Society for Invertebrate Morphology was founded during the 1st International Congress on Invertebrate Morphology, in Copenhagen, August 2008. The objectives of the society are to promote international collaboration and provide educational opportunities and training on invertebrate morphology, and to organize and promote the international congresses of invertebrate morphology, international meetings and other forms of scientific exchange.

The President is Dr. Gerhard Scholtz, Department of Biology, Humboldt-Universität zu Berlin, Germany.

Iris subg. Scorpiris

Iris subg. Scorpiris, commonly called Juno is a subgenus of Iris, representing the smooth-bulbed bulbous irises. For a while it was an independent genus Juno Tratt. in some classifications.There are around 60 different species of Juno irises, making it the largest group of bulbous irises.

They generally have thick fleshy storage roots (between a few and to several) under a fleshy-like bulb. Most are native to the Middle East and Central Asia (excluding China). There is a single Mediterranean species, 'Iris planifolia'.All the species are dormant in summer and then grow leaves in mid-winter or early spring.Many of the bulbs produce scented flowers. Most bulbs are not frost hardy and are best grown in a bulb frame or alpine house.It consists of a single section, Scorpiris.

Kutzneria

Kutzneria is a genus of bacteria in Phylum Actinobacteria. Three species of Kutzneria have been described as of 2001. This genus was named after Hans-Jürgen Kutzner, a German microbiologist.

Lichen morphology

Lichen morphology includes lichen growth forms used to group lichens by "vegetative" thallus types, and forms of "non-vegetative" reproductive parts. Some lichen thalli have the aspect of leaves (foliose lichens); others cover the substrate like a crust (crustose lichens) (illustration, right), others such as the genus Ramalina adopt shrubby forms (fruticose lichens), and there are gelatinous lichens such as the genus Collema.Although the form of a lichen is determined by the genetic material of the fungal partner, association with a photobiont is required for the development of that form. When grown in the laboratory in the absence of its photobiont, a lichen fungus develops as an undifferentiated mass of hyphae. If combined with its photobiont under appropriate conditions, its characteristic form emerges, in the process called morphogenesis. In a few remarkable cases, a single lichen fungus can develop into two very different lichen forms when associating with either a green algal or a cyanobacterial symbiont. Quite naturally, these alternative forms were at first considered to be different species, until they were found growing in a conjoined manner.

There is evidence to suggest that the lichen symbiosis is parasitic or commensalistic, rather than mutualistic. The photosynthetic partner can exist in nature independently of the fungal partner, but not vice versa. Furthermore, photobiont cells are routinely destroyed in the course of nutrient exchange. The association is able to continue because reproduction of the photobiont cells matches the rate at which they are destroyed.Under magnification, a section through a typical foliose lichen thallus reveals four layers of interlaced fungal filaments. The uppermost layer is formed by densely agglutinated fungal hyphae building a protective outer layer called the cortex, which can reach several hundred μm in thickness. This cortex may be further topped by an epicortex 0.6-1μm thick in some Parmeliaceae, which may be with or without pores, and is secreted by cells—it is not itself cellular. In lichens that include both green algal and cyanobacterial symbionts, the cyanobacteria may be held on the upper or lower surface in small pustules called cephalodia. Beneath the upper cortex is an algal layer composed of algal cells embedded in rather densely interwoven fungal hyphae. Each cell or group of cells of the photobiont is usually individually wrapped by hyphae, and in some cases penetrated by an haustorium. Beneath this algal layer is a third layer of loosely interwoven fungal hyphae without algal cells. This layer is called the medulla. Beneath the medulla, the bottom surface resembles the upper surface and is called the lower cortex, again consisting of densely packed fungal hyphae. The lower cortex of foliose lichens often bears rootlike fungal structures known as rhizines, which serve to attach the thallus to the substrate on which it grows. Lichens also sometimes contain structures made from fungal metabolites, for example crustose lichens sometimes have a polysaccharide layer in the cortex. Although each lichen thallus generally appears homogeneous, some evidence seems to suggest that the fungal component may consist of more than one genetic individual of that species. This seems to also be true of the photobiont species involved.

A podetium (plural podetia) is a lichenized stem-like structure of an apothecium rising from the primary body of the thallus. Since it is part of the reproductive tissue, it is not considered part of the thallus. The podetium may be branched, and sometimes cup-like. It usually bears the pycnidia or apothecia or both.

Morphogenesis

Morphogenesis (from the Greek morphê shape and genesis creation, literally, "beginning of the shape") is the biological process that causes an organism to develop its shape. It is one of three fundamental aspects of developmental biology along with the control of cell growth and cellular differentiation, unified in evolutionary developmental biology (evo-devo).

The process controls the organized spatial distribution of cells during the embryonic development of an organism. Morphogenesis can take place also in a mature organism, in cell culture or inside tumor cell masses. Morphogenesis also describes the development of unicellular life forms that do not have an embryonic stage in their life cycle, or describes the evolution of a body structure within a taxonomic group.

Morphogenetic responses may be induced in organisms by hormones, by environmental chemicals ranging from substances produced by other organisms to toxic chemicals or radionuclides released as pollutants, and other plants, or by mechanical stresses induced by spatial patterning of the cells.

Morphological analysis

Morphological analysis is the analysis of morphology in various fields:

Morphological analysis (problem-solving) or general morphological analysis, a method for exploring all possible solutions to a multi-dimensional, non-quantified problem

Analysis of morphology (linguistics), the internal structure of words

Analysis of morphology (biology), the form and structure of organisms and their specific features

Mathematical morphology, a theory and technique for analysis and processing of images and geometrical structures

Morphological dictionary, in computational linguistics, a linguistic resource that contains correspondences between surface form and lexical forms of words

Organography

Organography (from Greek όργανο, organo, "organ"; and -γραφή, -graphy) is the scientific description of the structure and function of the organs of living things.

Orthonectida

Orthonectida () is a small phylum of poorly known parasites of marine invertebrates that are among the simplest of multi-cellular organisms. Members of this phylum are known as orthonectids.

Phenice method

The Phenice method is a form of gross morphological analysis used to determine the sex of an unidentified human skeleton based on three characteristics of the pelvis: the ventral arc, sub-pubic concavity, and the medial aspect of the ischiopubic ramus. It is named after T. W. Phenice, who first described the method in a 1969 paper. The Phenice method should only be used for adult individuals because inter-sex differences in the morphology of the pelvis are secondary sexual characteristics present only in post-pubertal individuals.

Robustness (morphology)

In biology, robustness is used to describe a species with a morphology based on strength and a heavy build. The alternative morphology is the gracile body type.

For example, comparing similar species, rats have robust body types while mice are gracile. Male and female members of the same species may display sexual dimorphism and have robust and gracile morphologies.The terms "robust" vs. "gracile" are used relatively in the context of human evolution, to distinguish:

"robust" vs. "gracile" australopithecines, see Paranthropus

"robust" archaic humans vs. "gracile" anatomically modern humans

"robust" early modern humans (Cro-Magnon) vs. "gracile" Epipaleolithic humans (Combe-Capelle)

Synthetic morphology

Synthetic morphology is a sub-discipline of the broader field of synthetic biology.

In standard synthetic biology, artificial gene networks are introduced into cells, inputs (e.g. chemicals, light) are applied to those networks, and the networks perform logical operations on them and output the result of the operation as the activity of an enzyme or as the amount of green fluorescent protein. Using this approach, synthetic biologists have demonstrated the ability of their gene networks to perform Boolean computation, to hold a memory, and to generate pulses and oscillation.

Synthetic morphology extends this idea by adding output modules that alter the shape or social behaviour of cells in response to the state of the artificial gene network. For example, instead of just making a fluorescent protein, a gene network may switch on an adhesion molecule so that cells stick to each other, or activate a motility system so that cells move. It has been argued that the formation of properly-shaped tissues by mammalian cells involves mainly a set of about ten basic cellular events (cell proliferation, cell death, cell adhesion, differential adhesion, cell de-adhesion, cell fusion, cell locomotion, chemotaxis, haptotaxis, cell wedging). Broadly similar lists exist for tissues of plants, fungi etc. In principle, therefore, a fairly small set of output modules might allow biotechnologists to 'program' cells to produce artificially-designed arrangements, shapes and eventually 'tissues'.

The term synthetic morphology was introduced to the peer reviewed scientific literature in 2008 and is now becoming more widely used both in peer-reviewed literature and texts.

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