Ecophenotypic variation
Encyclopedia
Ecophenotypic variation ("ecophenotype") refers to phenotypical variation
as a function of life station. In wide-ranging species, the contributions of heredity
and environment are not always certain, but their interplay can sometimes be determined by experiment.
s often have much flexibility in the modification and expression of phenotype
s; in many organisms these phenotypes are very different under varying environmental conditions. The plant Hieracium umbellatum is found growing in two different habitats in Sweden. One habitat is rocky sea-side cliffs, where the plants are bushy with broad leaves and expanded inflorescence
s; the other is among sand dunes where the plants grow prostrate with narrow leaves and compact inflorescences. These habitats alternate along the coast of Sweden and the habitat that the seeds of H. umbellatum land in determines the phenotype that grows.. Invasive plants
such as the honeysuckle
can thrive by altering their morphology
in response to changes in the environment, which gives them a competitive advantage. The more immediate responses shown by vascular plants to their environment, for instance a vine's ability to conform to the wall or tree upon which it grows, are not usually considered ecophenotypic, even though the mechanisms may be related.
, examples include the muricid
snail species Nucella lamellosa
, which in rough, shallow waters is generally less spiny than in deeper, quiet waters. In unionid
freshwater bivalves
, there are lake, small river, and large river forms of several species. In vertebrate
s, experiments on mice show reduced length of ears and tails in response to being reared in a lower temperature, a phenomenon known as Allen's rule
.
found that cephalic index
was to some degree dependent on where a child was born, independent of the child's genetic or cultural heritage.
Phenotype
A phenotype is an organism's observable characteristics or traits: such as its morphology, development, biochemical or physiological properties, behavior, and products of behavior...
as a function of life station. In wide-ranging species, the contributions of heredity
Heredity
Heredity is the passing of traits to offspring . This is the process by which an offspring cell or organism acquires or becomes predisposed to the characteristics of its parent cell or organism. Through heredity, variations exhibited by individuals can accumulate and cause some species to evolve...
and environment are not always certain, but their interplay can sometimes be determined by experiment.
Plants
Plants display the most obvious examples of ecophenotypic variation. One example are trees growing in the woods developing long straight trunks, with branching crowns high in the canopy, while the same species growing alone in the open develops a spreading form, branching much lower to the ground. GenotypeGenotype
The genotype is the genetic makeup of a cell, an organism, or an individual usually with reference to a specific character under consideration...
s often have much flexibility in the modification and expression of phenotype
Phenotype
A phenotype is an organism's observable characteristics or traits: such as its morphology, development, biochemical or physiological properties, behavior, and products of behavior...
s; in many organisms these phenotypes are very different under varying environmental conditions. The plant Hieracium umbellatum is found growing in two different habitats in Sweden. One habitat is rocky sea-side cliffs, where the plants are bushy with broad leaves and expanded inflorescence
Inflorescence
An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Strictly, it is the part of the shoot of seed plants where flowers are formed and which is accordingly modified...
s; the other is among sand dunes where the plants grow prostrate with narrow leaves and compact inflorescences. These habitats alternate along the coast of Sweden and the habitat that the seeds of H. umbellatum land in determines the phenotype that grows.. Invasive plants
Invasive species
"Invasive species", or invasive exotics, is a nomenclature term and categorization phrase used for flora and fauna, and for specific restoration-preservation processes in native habitats, with several definitions....
such as the honeysuckle
Honeysuckle
Honeysuckles are arching shrubs or twining vines in the family Caprifoliaceae, native to the Northern Hemisphere. There are about 180 species of honeysuckle, 100 of which occur in China; Europe, India and North America have only about 20 native species each...
can thrive by altering their morphology
Morphology
Morphology may mean:*Morphology , the study of the structure and content of word forms*Morphology , the study of the form or shape of an organism or part thereof...
in response to changes in the environment, which gives them a competitive advantage. The more immediate responses shown by vascular plants to their environment, for instance a vine's ability to conform to the wall or tree upon which it grows, are not usually considered ecophenotypic, even though the mechanisms may be related.
Animals
Since animals are far less plastic than plants, ecophenotypic variation is noteworthy. When encountered, it can cause confusion in identification if it is not anticipated. The most obvious examples are again common observations, as the dwarfing of aquarium fish living in a restricted environment. More interesting are examples where causation is less clear. Among mollusksMollusca
The Mollusca , common name molluscs or mollusksSpelled mollusks in the USA, see reasons given in Rosenberg's ; for the spelling mollusc see the reasons given by , is a large phylum of invertebrate animals. There are around 85,000 recognized extant species of molluscs. Mollusca is the largest...
, examples include the muricid
Muricidae
Muricidae, common name murex snails or rock snails, is a large and varied taxonomic family of small to large predatory sea snails. With approximately 1,600 living species the Muricidae represent almost 10% of the Neogastropoda. Additionally, 1,200 fossil species have been recognised...
snail species Nucella lamellosa
Nucella lamellosa
Nucella lamellosa is a species of sea snail, a marine gastropod mollusk in the family Muricidae, the murex snails or rock snails....
, which in rough, shallow waters is generally less spiny than in deeper, quiet waters. In unionid
Unionidae
Unionidae is a family of freshwater mussels, the largest in the order Unionoida, the bivalve mollusks sometimes known as river mussels, naiads, or simply as unionids.The range of distribution for this family is world-wide...
freshwater bivalves
Freshwater bivalves
Freshwater bivalves are one kind of freshwater molluscs. They are bivalves which live in freshwater, as opposed to saltwater. Although the majority of species of bivalve molluscs live in the sea, a number of different families of bivalves live in freshwater...
, there are lake, small river, and large river forms of several species. In vertebrate
Vertebrate
Vertebrates are animals that are members of the subphylum Vertebrata . Vertebrates are the largest group of chordates, with currently about 58,000 species described. Vertebrates include the jawless fishes, bony fishes, sharks and rays, amphibians, reptiles, mammals, and birds...
s, experiments on mice show reduced length of ears and tails in response to being reared in a lower temperature, a phenomenon known as Allen's rule
Allen's rule
Allen's rule is a biological rule posited by Joel Asaph Allen in 1877. It states that endotherms from colder climates usually have shorter limbs than the equivalent animals from warmer climates.- Theory :...
.
Humans
In humans, environmental differences due to lifestyle choices are a consideration, for instance the differences between someone who spends much time on the sofa before the television, beer in hand, and an individual who spends his time in the gym or the soccer field can be pronounced. Franz BoasFranz Boas
Franz Boas was a German-American anthropologist and a pioneer of modern anthropology who has been called the "Father of American Anthropology" and "the Father of Modern Anthropology." Like many such pioneers, he trained in other disciplines; he received his doctorate in physics, and did...
found that cephalic index
Cephalic index
Cephalic index is the ratio of the maximum width of the head multiplied by 100 divided by its maximum length ....
was to some degree dependent on where a child was born, independent of the child's genetic or cultural heritage.