Comparative Vertebrate Anatomy Notes PDF

COMPANA S.Y. ‘24 - ‘25 | SEM 1 | KARDONG 2019 WEEK 1: LESSON NAME – WEEK 2 – these characters are used as the basis for 1.0 INTRODUCTION TO COMPARATIVE establishing relatio...

COMPANA S.Y. ‘24 - ‘25 | SEM 1 | KARDONG 2019 WEEK 1: LESSON NAME – WEEK 2 – these characters are used as the basis for 1.0 INTRODUCTION TO COMPARATIVE establishing relationships between species EVOLUTIONARY MORPHOLOGY VERTEBRATE ANATOMY evidence of past evolutionary changes is inscribed in animal structure 1.1 COMPARATIVE MORPHOLOGY each modern group living today carries mementos of the evolutionary course traveled by its ancestors Deals with anatomy and its significance Use of comparison in comparative morphology Evidence can find in the fossils is essential Emphasizes the functional and evolutionary 1.2 HISTORICAL PREDECESSORS IN themes vertebrates carry within their EVOLUTION structures FUNCTIONAL MORPHOLOGY In Kardong (2019), pp. 5-15 read on the The discipline that relates a structure to its following great scientists of evolution function ○ Charles Darwin ○ Carolus Linnaeus helps formulate the questions we might ask of ○ Jean-Baptiste de Lamarck structure ○ Louis Agassiz ○ Ex. Homocercal vs heterocercal tail - ○ Alfred Russel Wallace Why do different fishes have different ○ Thomas Huxley tail shapes? ○ Georges Cuvier ○ Richard Owen Homocercal tail ○ found in teleost fishes (salmon, tuna, bangus etc) have swim bladder that helps in 1.3 MORPHOLOGICAL CONCEPTS buoyancy Intang - ○ They need not struggle to keep their Use to analyze design of form, function, and position in the water evolution. Useful concepts for analysis Heterocercal tail ○ Similarity (Homology vs Analogy vs ○ found in sharks and other fishes that Homoplasy) lack swim bladders - they sink ○ Symmetry (Radial vs Bilateral) ○ The extended lobe provides lift during ○ Segmentation (Metamerism) swimming. 1.4 SIMILARITIES Homologous structures ○ two or more features that share a common ancestry ○ bird's wing and the mole's arm trace their common ancestry to reptiles Analogous structures important to taxonomists who use the ○ perform similar functions, but they structure of animals to define characters may or may not have similar ancestry ○ wings of bats and bees Homoplastic structures PPT | LECTURE | TEXTBOOK : KARDONG 2019 COMPANA SEM1 REVIEWER PAGE 1  COMPANA S.Y. ‘24 - ‘25 | SEM 1 | KARDONG 2019 WEEK 1: LESSON NAME ○ look alike and may or may not be ○ - Tapeworms - segmentation is the homologous or analogous basis for amplifying reproductive ○ in addition to being homologous and output analogous, turtle and dolphin flippers ○- Annelids (earthworms) have also look superficially similar segmented bodies that provide ○ obvious examples come from mimicry support and locomotion or camouflage (insects have wings ○ - Vertebrates - segmentation is less shaped and sculptured like leaves) extensive than segmentation among invertebrates musculature is laid out in segmental blocks, and nerves and blood vessels supplying it follow this segmental pattern, but segmentation goes no deeper. 1.7 BIOLOGICAL ROLES 1.5 SYMMETRY refers to how the part is used in the environment during the course of the organism's life history Radial symmetry the same structure may serve several ○ a body that is laid out equally from a biological roles central axis, so that any of several ex. Feathers planes passing through the center divides the animal into equal or E ○ insulation (thermoregulation) ○ aerodynamic contouring of body mirrored halves - ~ - shape G(flight) ○ ex. Invertebrates such as jellyfishes, ○ display during courtship sea urchins, and sea anemones G(reproduction) Bilateral symmetry ○ only the midsagittal plane divides the 1.8 PHYLOGENY body into two mirrored images, left and right summarized in dendrograms that depict treelike, branched connections between 1.6 SEGMENTATION groups the evolution of life is a continuous and body or structure built of repeating or connected process from one moment to the - duplicated sections next - compartmentalization ○ new species may evolve gradually or Metamere suddenly, but there is no break in the ○ each repeated section lineage ○ a break in the evolving lineage = Metamerism extinction - ○ the process that divides a body into duplicated sections Dendrograms can be used to express relative Significance of segmentation abundance and diversity PPT | LECTURE | TEXTBOOK : KARDONG 2019 COMPANA SEM1 REVIEWER PAGE 2  COMPANA S.Y. ‘24 - ‘25 | SEM 1 | KARDONG 2019 WEEK 1: LESSON NAME the "balloons" represent the relative numbers of vertebrates that existed in Monophyletic each group during various geological ○ Includes an ancestor and all its times descendants - only its descendants ○ Walang inampon walang itinakwil Polyphyletic 1.9 GROUPINGS ○ Formed on the basis of nonhomologous characters Traditional systematics ○ May inaampon ○ places together organisms with ○ Hindi kadugo -similar or homologous characteristics Paraphyletic Phylogenetic systematics ○ Include a common ancestor and O ○ places together organisms belonging some, but not all, of its descendants; to the same clade (cladistic) - used for convenience ○ 1.10 CLADE organisms in a lineage plus the ancestor they have in common taxon name refers to the to the genealogy itself not to characters per se Cladogram 1.12 PALEONTOLOGY AND GEOLOGIC AGES ○ the dendrogram depicting genealogy In Kardong (2019), pp. 29-31 read on the work ○ character transformations play a of paleontologist Alfred Romer and the central part importance of fossils in paleontology In Kardong (2019), pp. 39-43 read on the divisions and subdivisions of geologic time extant living still term for > 1.11 CLADISTIC GROUPING the more derived characteristics shared by two groups, the more likely it is they are closely related Ingroup ○ the assortment of taxa we are interested in examining Outgroup ○ close to but not part of this assortment and is used as a reference fossils may play an important reference role to better decide primitive and derived states of a character PPT | LECTURE | TEXTBOOK : KARDONG 2019 COMPANA SEM1 REVIEWER PAGE 3  COMPANA S.Y. ‘24 - ‘25 | SEM 1 | KARDONG 2019 WEEK 1: LESSON NAME 2.0 ORIGIN OF A CORDATE Vertebrata (craniates with vertebra) 2.2 CHORDATE CHARACTERISTICS - Most vertebrates have an endoskeleton ○ Endoskeleton for locomotion, support and protection of delicate organs Cephalochordates and urochordates ○ All marine animals ○ Lock bony or cartilaginous skeleton ○ Suspension feeders All chordates shares a common body design ○ Notochord - ○ Pharyngeal slits - ○ Endostyle or thyroid gland - - ○ Dorsal hollow nerve cord - ○ Postanal tail - No vertebrate will proceed without passing through these five characteristics in embryonic development 2.1 TAXONOMY OF PROTOCHORDATES AND VERTEBRATES Kingdom Animalia ○ Phylum Hemichordata ○ Phylum Chordata Subphylum Urochordata Subphylum Cephalochordata Subphylum Craniata – specialized head portion Hagfish (craniates without vertebra) PPT | LECTURE | TEXTBOOK : KARDONG 2019 COMPANA SEM1 REVIEWER PAGE 4  COMPANA S.Y. ‘24 - ‘25 | SEM 1 | KARDONG 2019 WEEK 1: LESSON NAME ○ The "gill" proper is a specialized I 2.3 NOTOCHORD structure of fish and larval amphibians for respiration in water Skeletal, babalutan ng vetebral para maging backbone Mesodermal in origin 2.5 EMBRYONIC COMPONENTS OF THE Ventral PHARYNX a slender rod that develops from the mesoderm Pharyngeal arches lies dorsal to the coelom but beneath and ○ Externally ectoderm parallel to the central nervous system (dorsal ○ Internally endoderm nerve cord) Pharyngeal clefts composed of a core of cells and fluid encased Pharyngeal pouches in a tough sheath of fibrous tissue Pharyngeal slits has the mechanical properties of an elastic ○ Not synonymous with gill slit rod ○ it can be flexed laterally from side to side but cannot be collapsed along its length During embryonic development ○ Head region - incorporated into skull floor ○ Trunk and tail - surrounded by cartilaginous or bony vertebra€ In adulthood ○ Protochordates - chief axial skeleton surrounded by notochord sheath ○ Agnathans - similar to protochordates with addition of lateral neural 2.6 PHARYNGEAL ARCHES cartilages ○ Fishes and amphibians - persist the A column of tissue which separates each length of the trunk and tail within the embryonic pharyngeal pouch or slit from the centrum next ○ Reptiles, birds and mammals has 4 components or blastemas which develop (amniotes) - disappears and becomes into: pulpy nucleus in mammal vertebrae ○ Skeleton ○ Muscles 2 2.4 PHARYNGEAL SLITS ○ Nerves ○ Blood vessels Total of 6 pairs of arches develop in Present in hemichordates, and pass on to the cranio-caudal sequence chordates - Indentations are present both external and the walls of the embryonic pharynx push out internal into a series of bays, the pharyngeal pouches ○ External - clefts lined with ectoderm First evolved to aid in feeding - allow flow of ○ Internal - pouches lined with water endoderm current Pharyngeal slit = gill slits PPT | LECTURE | TEXTBOOK : KARDONG 2019 COMPANA SEM1 REVIEWER PAGE 5  COMPANA S.Y. ‘24 - ‘25 | SEM 1 | KARDONG 2019 WEEK 1: LESSON NAME Cranial nerves (branches 5, 7, 9 and 10) which innervate muscles and provide sensory input to the brain An aortic arch that connects the ventral and dorsal aortas 2.8 PHARYNGEAL CLEFTS Ectodermally lined grooves on the outside of the embryonic pharynx Only the first cleft is important ○ Develops into the external auditory meatus of the ear ○ Provides the outer epithelium of the tympanic membrane Clefts are lost in development because of proliferation of the underlying mesoderm 2.9 PHARYNGEAL POUCHES Arises as diverticula of endoderm or foregut Grows toward the surface of the animal Establish the limits of the pharynx Max. number in jawed craniates: ○ 8 - basal shark 2.7 COMPONENTS OF PHARYNGEAL ○ 15 - living agnathans ARCHES Pharyngeal clefts grows toward each pouch Supportive skeletal elements (pharyngeal and is separated from each other via the skeleton) pharyngeal plate Striated muscles that operate the arch Contribute to the development of a surprising (branchiomeric muscles) diversity of structures PPT | LECTURE | TEXTBOOK : KARDONG 2019 COMPANA SEM1 REVIEWER PAGE 6  COMPANA S.Y. ‘24 - ‘25 | SEM 1 | KARDONG 2019 WEEK 1: LESSON NAME 2.11 ENDOSTYLE OR THYROID GLAND 3 Endostyle is a glandular groove in the floor of the pharynx and is involved in filter feeding Thyroid gland is an endocrine gland that produces hormones Homologous structures ○ Both arises from the floor of the pharynx and are involved in iodine 2.10 PHARYNGEAL SLITS metabolism Formed between the pharynx and the exterior - when the pharyngeal plate ruptures Pouches may open to the exterior as slits: ○ Permanent adults that live in water and ○ Temporary breathe via gills 2.12 DORSAL AND TUBULAR NERVE CORD 4 adults live on land the CNS of all animals is ectodermal in embryonic origin only in chordates ○ neural plate of cells invaginates as a tube (nerve tube) located dorsally within the embryo just above the notochord ○ the nerve cord (ventral) lies above the gut and is hollow along its entire length surrounding the neurocoel In most nonchordate embryos ○ ectodermal cells forming the CNS do not form placodes; instead, surface cells individually move inward to assemble into the basic nervous system ○ the nerve cord is ventral in position, below the gut, and solid PPT | LECTURE | TEXTBOOK : KARDONG 2019 COMPANA SEM1 REVIEWER PAGE 7  COMPANA S.Y. ‘24 - ‘25 | SEM 1 | KARDONG 2019 WEEK 1: LESSON NAME 2.13 POSTANAL TAIL 5 represents a posterior elongation of the body extending beyond the anus primarily an extension of the segmental musculature and notochord ○ the chordate locomotor apparatus ○ provides propelling force in many aquatic species the anus in nonchordates is at the posterior terminal end of the body PPT | LECTURE | TEXTBOOK : KARDONG 2019 COMPANA SEM1 REVIEWER PAGE 8