Detours/shunts are developmental ‘vestiges’ in the shift from fetal to neonatal circulation. Werth, A.J. Vestiges of the natural history of development. Evo Edu Outreach 7, 12 (2014). https://t.co/8RKykbbziB
Vestigial. “The term vestige refers to something that has lost a former function during evolutionary change, such as our appendix, tail bone, and goose bumps, or the rudimentary pelvic bones of cetaceans and some large snakes.” https://t.co/3gaQdKvHOq
"Ultimately, even development—as a whole, and including every developmental process—evolves." https://t.co/2aohKfkRQo
"There are central distinctions between evolution and development." https://t.co/2aohKfkRQo
"In the end, both phylogenetic vestiges and ontogenetic ‘vestiges’ evolve." https://t.co/2aohKfkRQo
"These underlying and inherited genetic instructions are essential for vestigiality." https://t.co/2aohKfkRQo
"Vestigial features (are) expressed in the phenotypic change, whether structural or behavioral." https://t.co/2aohKfkRQo
"Vestigial features cannot be defined as remnants or residues of events...unless they alter the underlying DNA." https://t.co/2aohKfkRQo
Vestigial features "can evolve, or rather persist, as with...a vestigial structure, process, or behavior." https://t.co/2aohKfkRQo
"Vestigial features are properties of species—they apply to all members of a species, and are inherited." https://t.co/2aohKfkRQo
"scars and other traces of injury...do not conform to a fundamental tenet of vestigiality as commonly understood." https://t.co/2aohKfkRQo
"Whereas scars and other traces of injury...remain a part of that organism, they are not inherited. https://t.co/2aohKfkRQo
Vestigial phenotype and genotype. "Both kinds of vestiges result from solitary events in individual organisms." https://t.co/2aohKfkRQo
Vestigial remains are "not only in the phenotype we see, but also in the" genotype. https://t.co/2aohKfkRQo
"Both evolution and development might be said to leave vestigial remains." https://t.co/2aohKfkRQo
Molecular vestiges may be non-functional, like perhaps some junk DNA. https://t.co/2aohKfkRQo
"Chance events of phylogeny can likewise leave ‘vestiges’ in the form of molecules and nucleic acid sequences." https://t.co/2aohKfkRQo
"Illnesses, injuries, and other accidents of ontogeny often leave remains in the form of scars." https://t.co/2aohKfkRQo
Known examples: snail shells, fish limbs, hen’s teeth. The silent toolkit. https://t.co/2aohKfkRQo
Known: "the profound consequences of these shifts...in external phenotypes." https://t.co/2aohKfkRQo
Unknown: "the evolutionary significance of ‘internal’ molecular mechanisms, which are often silent or neutral." https://t.co/2aohKfkRQo
"We can tweak regulatory genes of embryonic chicks to ‘switch on’ still-present structural genes" for teeth. https://t.co/2aohKfkRQo
"No living birds have teeth." https://t.co/2aohKfkRQo
"Minor molecular changes can provide major anatomical shifts, all of which might prove pivotal in evolution." https://t.co/2aohKfkRQo
5’ Hoxd enhancer CsC "is involved in turning embryonic limb buds into fish fins as well as tetrapod hands." https://t.co/2aohKfkRQo
"Overexpression of the hox13a gene in zebrafish...causes...proliferation of distal cartilaginous tissue." https://t.co/2aohKfkRQo
"Overexpression of the hox13a gene in zebrafish (Danio rerio) causes fin reduction." https://t.co/2aohKfkRQo
"Exposure to platinum causes young snails to develop into shell-less, slug-like gastropod molluscs." https://t.co/2aohKfkRQo
Numerous studies "revealed how minor genetic and molecular tweaks have major ramifications on organismal phenotype." https://t.co/2aohKfkRQo
"The interplay between gene, environment, and anatomy, both dynamically mutating and dynamically selected." https://t.co/2aohKfkRQo
"We must be mindful of the perpetually unfolding interplay between gene, environment, and anatomy." https://t.co/2aohKfkRQo
"No aspect of an organism is static." https://t.co/2aohKfkRQo
Leigh Van Valen: "Evolution is the control of development by ecology”. https://t.co/2aohKfkRQo
"The dynamic relation between phylogeny and ontogeny" cannot be denied. https://t.co/2aohKfkRQo
"The vestigial remnants of...evolutionary changes provide key evidence for evolutionary changes cannot be denied." https://t.co/2aohKfkRQo
Vestigial attributes "reflect the intertwined nature of phylogenetic and ontogenetic transformations." https://t.co/2aohKfkRQo
"Such remnants help us to see the distinction between these related and highly similar yet discrete processes." https://t.co/2aohKfkRQo
Vestiges, along with "other historical holdovers, reveal the dynamic interplay between evolution and development." https://t.co/2aohKfkRQo
"Vestiges are not mere curiosities or footnotes." https://t.co/2aohKfkRQo
Paedomorphosis is "another way in which...phylogeny and ontogeny are reflected in their mutual history." https://t.co/2aohKfkRQo
Paedomorphosis "is yet another way in which organismal features are retained rather than changed." https://t.co/2aohKfkRQo
Paedomorphosis: "the external filamentous gills of aquatic salamanders." https://t.co/2aohKfkRQo
Paedomorphosis is "the retention of ‘child-like’ larval or juvenile forms." https://t.co/2aohKfkRQo
"Licking of human faces by dogs might...initially evolved in ancestral wolves as a submissive behavior." https://t.co/2aohKfkRQo
"Licking of human faces by dogs...now aids in bonding and socialization." https://t.co/2aohKfkRQo
"Licking of human faces by dogs might be seen as a behavioral exaptation." https://t.co/2aohKfkRQo
Exaptations of avian feathers, "now also serve courtship (display) and locomotor (flight) functions." https://t.co/2aohKfkRQo
Exaptations of avian feathers, "which initially arose as thermoregulatory (insulating) structures." https://t.co/2aohKfkRQo
Exaptations of lungs of early fishes, "which in most osteichthyan clades evolved into swim bladders for buoyancy." https://t.co/2aohKfkRQo
"Examples of classical structural exaptations include the lungs of early fishes." https://t.co/2aohKfkRQo
"As with vestiges, an exaptation can be a structure but it can also be a behavior or process." https://t.co/2aohKfkRQo
"With exaptations (‘pre-adaptations’) the function changes over time, yielding other historical information." https://t.co/2aohKfkRQo
But gomphotheres "went extinct over 10,000 years ago." https://t.co/2aohKfkRQo
The calabash fruit was adapted "for seed dispersal by gomphotheres, large, elephant-like mammals." https://t.co/2aohKfkRQo
"The large, hard-shelled, gourd-type fruit of the calabash (Crescentia) tree" is an ‘anachronistic’ adaptation. https://t.co/2aohKfkRQo
Adaptations reveal lessons: "particularly true when environmental changes render an adaptation apparently useless." https://t.co/2aohKfkRQo
"Adaptations too reveal important lessons about the past." https://t.co/2aohKfkRQo
"Adaptations represent static retention of features because stabilizing selection culls less optimal forms." https://t.co/2aohKfkRQo
"Adaptionist stories “are not about evolution so much as about its absence”." https://t.co/2aohKfkRQo
"What ultimately marks vestiges and other ‘holdover’ phenomena is a distinct lack of change." https://t.co/2aohKfkRQo
"To most minds evolution is a steady progression of change." https://t.co/2aohKfkRQo
"Closely related lineages...and their extinct common ancestors...tell us...about extant taxa." https://t.co/2aohKfkRQo
"Even sexual dimorphism in body form...represent retention of former evolutionary and developmental conditions." https://t.co/2aohKfkRQo
"A similar example comes from the origin of mammary glands as derived sweat glands." https://t.co/2aohKfkRQo
Mammalian inner ear "provide much evidence as to joint ontogenetic and phylogenetic transformation." https://t.co/2aohKfkRQo
Evo-devo changes of the mammalian inner ear, "where they are still functional, but with a new function." https://t.co/2aohKfkRQo
The mammalian middle ear ossicles, "now play a key role in hearing by amplifying sounds." https://t.co/2aohKfCsHW
The mammalian middle ear ossicles, "all of which are derived from jaw bones of ancestral reptiles." https://t.co/2aohKfkRQo
"A major remnant of evolutionary and developmental history involves the mammalian middle ear ossicles." https://t.co/2aohKfkRQo
Phyletic and phylogenetic: "a history that can be concurrently approached from two directions." https://t.co/2aohKfkRQo
Atavistic and homologous clues are sometimes "best viewed through the prism of divergent lineages." https://t.co/2aohKfkRQo
"Atavistic and homologous clues can be seen as revealing historical changes within a single evolutionary lineage." https://t.co/2aohKfkRQo
"Tantalizing residues...of earlier forms often remain visible even in later stages of evolution and development." https://t.co/2aohKfkRQo
"In development as in evolution, the basic outline is not always erased." https://t.co/2aohKfkRQo
The "framework of ancestral, plesiomorphic features that is later supplanted or overlain by derived apomorphies." https://t.co/2aohKfkRQo
von Baer’s Law "is not surprising given the centrality of mosaicism in evolutionary and developmental change." https://t.co/2aohKfkRQo
"There is no doubt that early embryos resemble each other more closely than do late-stage embryos (von Baer’s Law)." https://t.co/2aohKfkRQo
"The gubernaculum testis...is homologous to the round ligament that suspends the ovary." https://t.co/2aohKfkRQo
Homologies of male and female genital structures "are evo-devo traces of shared early origins." https://t.co/2aohKfkRQo
Homologies of male and female genital structures: "the scrotum and labia majora." https://t.co/2aohKfkRQo
Homologies of male and female genital structures—"for example, the male glans penis and female clitoris." https://t.co/2aohKfkRQo
There are "many well-known homologies of male and female genital structures." https://t.co/2aohKfkRQo
It is clear "that the structures that remain are mere shadows of their former ontogenetic and phylogenetic states." https://t.co/2aohKfkRQo
"Remnants of solely evolutionary or developmental alteration—plainly, these changes are intertwined." https://t.co/2aohKfkRQo
"It is difficult...to discern these transformations as remnants of solely evolutionary or developmental alteration." https://t.co/2aohKfkRQo
"Remains of the notochord are retained as the gel-like nucleus pulposus at the center of intervertebral discs." https://t.co/2aohKfkRQo
The chordate postanal tail is an "evolutionary vestige when the tail is partly or wholly non-functional in adults." https://t.co/2aohKfkRQo
The chordate postanal tail. "The tail is retained in...nearly all adult vertebrates" except apes and frogs. https://t.co/2aohKfkRQo
The chordate postanal tail. "The tail is retained in many ‘adult’ (i.e., sexually mature) chordates." https://t.co/2aohKfkRQo
"All chordates possess, again at some stage of the life cycle, a postanal tail." https://t.co/2aohKfkRQo
The endostyle "represents another relic of shared ontogenetic and phylogenetic transformations." https://t.co/2aohKfkRQo
The endostyle is "(from its metabolic and iodine-concentrating activities)...homologous to the thyroid gland." https://t.co/2aohKfkRQo
"The endostyle—another of the six diagnostic chordate features." https://t.co/2aohKfkRQo
"Homologies of these jointly conserved evolutionary-developmental structures constitute...historical residues." https://t.co/2aohKfkRQo
Phylum Chordata: "it is not possible to disconnect ontogenetic from phylogenetic remnants in this instance." https://t.co/2aohKfkRQo
Phylum Chordata: "postanal tail; pharyngeal slits; and endostyle." https://t.co/2aohKfkRQo
Phylum Chordata: "the notochord; single, dorsal, hollow neural tube; myomeres (segmental muscle units)." https://t.co/2aohKfkRQo
"The six basic ‘diagnostic’ features of the Phylum Chordata, found in all chordates...in their life cycle." https://t.co/2aohKfkRQo
Sometimes "it is not easy to disentangle the evolutionary and developmental processes" to produce new phenotypes. https://t.co/2aohKfkRQo