What's the difference between evolution and heterochrony?
Evolution
Definition:
(n.) The act of unfolding or unrolling; hence, in the process of growth; development; as, the evolution of a flower from a bud, or an animal from the egg.
(n.) A series of things unrolled or unfolded.
(n.) The formation of an involute by unwrapping a thread from a curve as an evolute.
(n.) The extraction of roots; -- the reverse of involution.
(n.) A prescribed movement of a body of troops, or a vessel or fleet; any movement designed to effect a new arrangement or disposition; a maneuver.
(n.) A general name for the history of the steps by which any living organism has acquired the morphological and physiological characters which distinguish it; a gradual unfolding of successive phases of growth or development.
(n.) That theory of generation which supposes the germ to preexist in the parent, and its parts to be developed, but not actually formed, by the procreative act; -- opposed to epigenesis.
(n.) That series of changes under natural law which involves continuous progress from the homogeneous to the heterogeneous in structure, and from the single and simple to the diverse and manifold in quality or function. The pocess is by some limited to organic beings; by others it is applied to the inorganic and the psychical. It is also applied to explain the existence and growth of institutions, manners, language, civilization, and every product of human activity. The agencies and laws of the process are variously explained by different philosophrs.
Example Sentences:
(1) The process of sequence rearrangement appears to be a significant part of the evolution of the genome and may have a much greater effect on the evolution of the phenotype than sequence alteration by base substitution.
(2) It is argued that this process drove the evolution of present 5' and 3' splice sites from a subset of proto-splice sites and also drove the evolution of a more efficient splicing machinery.
(3) It has been possible to observe the evolution of their lesions.
(4) Gradual evolutionary change by natural selection operates so slowly within established species that it cannot account for the major features of evolution.
(5) The early absolute but transient dependence of these A-MuLV mast cell transformants on a fibroblast feeder suggests a multistep process in their evolution, in which the acquisition of autonomy from factors of mesenchymal cell origin may play an important role.
(6) The evolution and function of multiple forms of a given photosynthetic pigment in vivo are discussed.
(7) Evolution of serological procedures was continuous through this period but without clear evidence of improvement in performance of antibody detection although performance in the UK appears to be comparable with that elsewhere.
(8) With the successful culture of these tissues, their development, biochemistry, and physiology, potentially of great importance in understanding early vertebrate evolution, can be better understood.
(9) This situation highlights the potential importance of molecules with different inheritance patterns in elucidating complex cases of reticulate evolution.
(10) The evolution of tissue damage in compressive spinal cord injuries in rats was studied using an immunohistochemical technique and by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis.
(11) Republican presidential hopeful Scott Walker has refused to say whether he believes in the theory of evolution, arguing that it is “a question a politician shouldn’t be involved in one way or the other”.
(12) It is mentioned that the lack of a valuable status for industrial physicians may adversely affect the evolution of training programs in Switzerland.
(13) Assessment of a predictive factor for the evolution of the disease is not yet possible.
(14) These studies indicate that, in three models of acute liver injury, the net influx of calcium across the plasma membrane is increased early in the evolution of the injury before irreversible damage occurs.
(15) The strong homology of mammalian L27' to yeast L29 suggests a function which has been conserved throughout evolution, and thus L27' may also be involved in peptidyl transferase activity.
(16) The diversity of the non-Hodgkin's groups, the continued evolution of histopathologic classifications, and the great frequency of advanced disease in the lymphocytic subgroups make the Ann Arbor classification of only limited value for the non-Hodgkin's lymphomas.
(17) We show how this model would explain the perinatal or infantile onset of the disease, the variability of the rate of evolution between the different SMA forms, and the fact that motoneuron loss is much more dramatic in SMA than in even advanced cases of myopathy.
(18) Evolution into acute myeloid leukemia occurred in 11 patients.
(19) On evaluation of the time evolution of the symptoms we found that most patients continued to show them until September each year.
(20) The evolution with time of cardio-respiratory variables, blood pressure and body temperature has been studied on six males, resting in semi-nude conditions during short (30 min) cold stress exposure (0 degree C) and during passive recovery (60 min) at 20 degrees C. Passive cold exposure does not induce a change in HR but increases VO2, VCO2, Ve and core temperature Tre, whereas peripheral temperature is significantly lowered.
Heterochrony
Definition:
(n.) In evolution, a deviation from the typical sequence in the formation of organs or parts.
Example Sentences:
(1) A detailed analysis of the frontal, medial prefrontal and hippocampal regions also shows a heterochrony within these regions.
(2) These groups correspond to different stages of neuroblast development in vivo and their presence in the tissue cultures of different brain regions reflects the heterochrony of cell development in these regions.
(3) Direct development is achieved primarily by heterochrony, that is, by the abbreviation or elimination of larval developmental processes and the acceleration of processes involved in development of adult features.
(4) Ontogeny in the tube-crested dinosaur Parasaurolophus (Hadrosauridae) and heterochrony in hadrosaurids.
(5) The concepts of chronogenetics, heterochrony, and developmental field defects appear relevant to yet another set of patients with chromosome anomalies.
(6) It has been pointed out, that there is a complex heterochrony of regional development in the brain.
(7) Certain single malformations such as holoprosencephaly immediately suggest heterochrony by their resemblance to antecedent phylogenetic or embryologic structures.
(8) Some male sterile mutations can decouple the development of the different components of a germ cell, i.e., they may lead to a heterochrony of the development of the different subcellular structures, or they may permit the differentiation of some components of a germ cell even in the complete absence of an organelle.
(9) He has only mentioned the concept of heterochrony to which we give much more importance nowadays.
(10) The role of altered developmental timing or heterochrony in morphologic evolution has intrigued classical and modern biologists.
(11) During prenatal life of monkey and man in the development of the frontal area the phenomena of heterochrony (common for both species) and anabolia (peculiar for man only) are observed (the appearance of new more complex structures).
(12) It is theorized that hormones are a major factor in the non-random regulation of cellular heterochrony in tumourigenesis.
(13) The data obtained suggest a heterochrony and different rate of the functional callosal connexions maturation in projection and associative areas of the cortex.
(14) The perspective of heterochrony stresses the molecular history and hierarchy which is recapitulated with each pregnancy, and reconciles apparent discrepancies between the rates of molecular and morphologic evolution.
(15) In terms of heterochrony such a pattern most likely is the result of a process termed "acceleration", i.e.
(16) Notwithstanding this, gross regularities of heterochrony in the neurogenetic behavior of the different segments lead to a definition of elemental longitudinal compartments of the forebrain and mesencephalon (floor, paramedian, basal, and alar regions) on the basis of precocious differentiation of the basal region and retarded differentiation of the paramedian and alar regions.
(17) Molecular mechanisms underlying heterochrony are thereby described.
(18) We propose that such a shift in relative timing of the developmental phenomena involved inhibits pigment cell migration in embryos of the white axolotl mutant and, accordingly, that the restricted pigmentation of the mutant larva is generated through heterochrony.
(19) In its normal ontogeny, Hydractinia symbiolongicarpus, a closely related hydractiniid hydroid, not only shows morphological heterochrony similar to that induced in P. carnea by DNP, but also shows a pattern of gastrovascular flow similar to that observed in P. carnea under treatment with DNP.
(20) In view of elucidating the origin of this heterochrony, we make an electrophoretic study of the different extracts from juveniles, adults in activity, in natural sleep and awakning.