Morphogenetic field
Encyclopedia
- This article is about the concept in developmental biology. For Rupert SheldrakeRupert SheldrakeRupert Sheldrake is an English scientist. He is known for having proposed an unorthodox account of morphogenesis and for his research into parapsychology. His books and papers stem from his theory of morphic resonance, and cover topics such as animal and plant development and behaviour, memory,...
's concept of the same name, see the corresponding section of Morphic field.
In developmental biology
Developmental biology
Developmental biology is the study of the process by which organisms grow and develop. Modern developmental biology studies the genetic control of cell growth, differentiation and "morphogenesis", which is the process that gives rise to tissues, organs and anatomy.- Related fields of study...
, a morphogenetic field is a group of cell
Cell (biology)
The cell is the basic structural and functional unit of all known living organisms. It is the smallest unit of life that is classified as a living thing, and is often called the building block of life. The Alberts text discusses how the "cellular building blocks" move to shape developing embryos....
s able to respond to discrete, localized biochemical signals leading to the development of specific morphological structures or organ
Organ (anatomy)
In biology, an organ is a collection of tissues joined in structural unit to serve a common function. Usually there is a main tissue and sporadic tissues . The main tissue is the one that is unique for the specific organ. For example, main tissue in the heart is the myocardium, while sporadic are...
s. The spatial and temporal extent of the embryonic fields are dynamic, and within the field is a collection of interacting cells out of which a particular organ is formed. As a group, the cells within a given morphogenetic field are constrained — i.e. cells in a limb field will become a limb tissue, those in a cardiac field will become heart tissue. Importantly, however, the specific cellular programming of individual cells in a field is flexible: an individual cell in a cardiac field can be redirected via cell-to-cell signaling to replace specific damaged or missing cells. Imaginal disc
Imaginal disc
An imaginal disc is one of the parts of a holometabolous insect larva that will become a portion of the outside of the adult insect during the pupal transformation. Contained within the body of the larva, there are pairs of discs that will form, for instance, the wings or legs or antennae or other...
s in insect larva
Larva
A larva is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle...
e are examples of morphogenetic fields.
Historical development
The concept of the morphogenetic field, fundamental in the early twentieth century to the study of embryological development, was first introduced in 1910 by Alexander G. Gurwitsch. Experimental support was provided by Ross Granville HarrisonRoss Granville Harrison
Ross Granville Harrison was an American biologist and anatomist credited as the first to work successfully with artificial tissue culture....
's experiments transplanting fragments of a newt embryo into different locations.
Harrison was able to identify "fields" of cells producing organs such as limbs, tail and gills and to show that these fields could be fragmented or have undifferentiated cells added and a complete normal final structure would still result. It was thus considered that it was the "field" of cells, rather than individual cells, that were patterned for subsequent development of particular organs. The field concept was developed further by Harrison's friend Hans Spemann
Hans Spemann
Hans Spemann was a German embryologist who was awarded a Nobel Prize in Physiology or Medicine in 1935 for his discovery of the effect now known as embryonic induction, an influence, exercised by various parts of the embryo, that directs the development of groups of cells into particular tissues...
, and then by Paul Weiss
Paul Alfred Weiss
Paul Alfred Weiss was an Austrian biologist who specialised in morphogenesis, development, differentiation and neurobiology...
and others.
By the 1930s, however, the work of geneticists, especially Thomas Hunt Morgan
Thomas Hunt Morgan
Thomas Hunt Morgan was an American evolutionary biologist, geneticist and embryologist and science author who won the Nobel Prize in Physiology or Medicine in 1933 for discoveries relating the role the chromosome plays in heredity.Morgan received his PhD from Johns Hopkins University in zoology...
, revealed the importance of chromosomes and genes for controlling development, and the rise of the new synthesis
Modern evolutionary synthesis
The modern evolutionary synthesis is a union of ideas from several biological specialties which provides a widely accepted account of evolution...
in evolutionary biology lessened the perceived importance of the field hypothesis. Morgan was a particularly harsh critic of fields since the gene and the field were perceived as competitors for recognition as the basic unit of ontogeny
Ontogeny
Ontogeny is the origin and the development of an organism – for example: from the fertilized egg to mature form. It covers in essence, the study of an organism's lifespan...
. With the discovery and mapping of master control genes, such as the homeobox
Homeobox
A homeobox is a DNA sequence found within genes that are involved in the regulation of patterns of anatomical development in animals, fungi and plants.- Discovery :...
genes the pre-eminence of genes seemed assured. But in the late twentieth century the field concept was "rediscovered" as a useful part of developmental biology. It was found, for example, that different mutations could cause the same malformations, suggesting that the mutations were affecting a complex of structures as a unit, a unit that might correspond to the field of early 20th century embryology.
Scott Gilbert proposes that the morphogenetic field is a middle ground between genes and evolution. That is, genes act upon fields, which then act upon the developing organism. Jessica Bolker describes morphogenetic fields not merely as incipient structures or organs, but as dynamic entities with their own localized development processes, which are central to the emerging field of evolutionary development ("evo-devo")
Evolutionary developmental biology
Evolutionary developmental biology is a field of biology that compares the developmental processes of different organisms to determine the ancestral relationship between them, and to discover how developmental processes evolved...
.