Comparative Anatomy of Comparative Anatomy of VertebratesVertebrates

Introduction: Terms, Concepts and HistoryIntroduction: Terms, Concepts and History

Prepared by: Mr. Ian Kenneth M. CabreraPrepared by: Mr. Ian Kenneth M. Cabrera

ObjectivesObjectives

• To know the common terminologies used in Comparative To know the common terminologies used in Comparative AnatomyAnatomy

• To be able to know the historical development of the subject To be able to know the historical development of the subject matter.matter.

• To identify the people behind its development and their To identify the people behind its development and their corresponding contributionscorresponding contributions

• To know the fundamental concept/principle of species To know the fundamental concept/principle of species development including structure, form and function.development including structure, form and function.

MeaningMeaning

• Comparative Anatomy, but to be more accurately – comparative Comparative Anatomy, but to be more accurately – comparative morphology, deals with the study of parts and structure (forms) and themorphology, deals with the study of parts and structure (forms) and the

corresponding functions of these forms of bodies of vertebratescorresponding functions of these forms of bodies of vertebrates. . • It is both descriptive and analytical. It is both descriptive and analytical.

• The course also deals with the study of natural history. Where did present The course also deals with the study of natural history. Where did present day species come from? Are present day species the same millions of years day species come from? Are present day species the same millions of years ago? What course did higher organisms went though in order arrive at such ago? What course did higher organisms went though in order arrive at such immutable complexity like what we know now of them today? Did we immutable complexity like what we know now of them today? Did we really originate from apes? really originate from apes?

• The subject also deals with species of animals which no longer inhabit the The subject also deals with species of animals which no longer inhabit the Earth and are known to us by fossil records.Earth and are known to us by fossil records.

The ToolThe Tool

The tool?The tool?

ComparisonComparison..

• of structures throws similarities of structures throws similarities and differences and differences

• it emphasizes the evolutionary it emphasizes the evolutionary and functional themes vertebrates and functional themes vertebrates possess within their innate possess within their innate structures. structures.

• also helps formulate the questions also helps formulate the questions we might inquire in the future.we might inquire in the future.

Central Theme?Central Theme?

Evolution of CharacteristicsEvolution of Characteristics

History of the Study: The People Responsible.History of the Study: The People Responsible.

Carl von Linne also Carl von Linne also Carolus LinnaeusCarolus Linnaeus 1707- 1707-1778 1778

– devised the binomial system devised the binomial system of naming plants and animals of naming plants and animals which became the basis of which became the basis of modern taxonomy.modern taxonomy.

– published published Systema NaturaeSystema Naturae

– argued that species were argued that species were immutable or unchangeable.immutable or unchangeable.

Jean Baptiste de LamarckJean Baptiste de Lamarck 1744-1829 1744-1829

• first to classify the animal first to classify the animal kingdom into invertebrate and kingdom into invertebrate and vertebratevertebrate

• published published Philosophie ZoologiquePhilosophie Zoologique

• acquired characteristics and road acquired characteristics and road to perfectionto perfection

Georges CuvierGeorges Cuvier 1769-1832 1769-1832

• also argued that species are also argued that species are immutable.immutable.

• he stated that the design of each he stated that the design of each animal could not have changed animal could not have changed since creation.since creation.

• organisms “must be understood as organisms “must be understood as functional wholes because the functional wholes because the parts and the function they served parts and the function they served were tightly related”.were tightly related”.

• published a 22-volume published a 22-volume masterpiece – masterpiece – NaturelleNaturelle des des PoisonsPoisons

Richard OwenRichard Owen 1804-1892 1804-1892

• developed concepts of homology developed concepts of homology and analogyand analogy

• obtained and described the first obtained and described the first good specimen of the primitive good specimen of the primitive bird bird ArchaeopteryxArchaeopteryx which which provided evidence for the theory provided evidence for the theory of evolution.of evolution.

• opposed the theory of evolution opposed the theory of evolution by natural selection.by natural selection.

• advocated the idea of the advocated the idea of the archetype, or ideal original archetype, or ideal original pattern, which served as a pattern, which served as a blueprint for species.blueprint for species.

Louis AgassizLouis Agassiz 1807-1873 1807-1873

• Swiss-American paleontologist Swiss-American paleontologist and geologist and geologist

• published published Studies on GlaciersStudies on Glaciers

• considered as the first teacher of considered as the first teacher of comparative anatomycomparative anatomy

• had the ability to draw with both had the ability to draw with both hands at once while speakinghands at once while speaking

Charles DarwinCharles Darwin 1809-1882 1809-1882

• developed the modern theory of developed the modern theory of evolutionevolution

• 2 books – 2 books – On the Origin of On the Origin of SpeciesSpecies and and The Descent of ManThe Descent of Man

• based on his journey and travels based on his journey and travels on the HMS Beagle to the on the HMS Beagle to the Galapagos islands in the Pacific Galapagos islands in the Pacific ocean.ocean.

• established the evolutionary basis, established the evolutionary basis, comparative, functional and comparative, functional and adaptive morphology and adaptive morphology and anatomy.anatomy.

Alfred Russel WallaceAlfred Russel Wallace 1823-1913 1823-1913

• developed the concept of survival developed the concept of survival of the fittestof the fittest

Thomas HuxleyThomas Huxley 1825-18951825-1895

• published published Comparative Anatomy Comparative Anatomy of Vertebratesof Vertebrates in 1871 in 1871

• established the modern concept of established the modern concept of the evolution of the vertebrate the evolution of the vertebrate skullskull

Terms and ConceptsTerms and Concepts

Homology Homology • refers to features of two or more organisms sharing common ancestryrefers to features of two or more organisms sharing common ancestry• it also refers to the correspondence in type of structure between parts or it also refers to the correspondence in type of structure between parts or

organs of different animalsorgans of different animals• clearly linked through time by continuity of fossil recordclearly linked through time by continuity of fossil record• shown to develop similarity in the embryo from identical primordial.shown to develop similarity in the embryo from identical primordial.• different appearance, common general make-updifferent appearance, common general make-up

example: the skeletons of the forelimbs of cats, the example: the skeletons of the forelimbs of cats, the wings of birds, the arms of humans, wings of birds, the arms of humans, and the wings of a bat.and the wings of a bat.

Analogy Analogy

• refers to features of two or more organisms sharing common refers to features of two or more organisms sharing common functionfunction

• correspondence in function of a structure in similar or different correspondence in function of a structure in similar or different organs or organ parts.organs or organ parts.

example: the fin of a fish and the flipper of a whale

the scales of fishes and reptiles

HomoplasyHomoplasy

• refers to features of two or more organisms which may be related refers to features of two or more organisms which may be related by similarity of appearance but cannot be explained by either by similarity of appearance but cannot be explained by either homology and analogy.homology and analogy.

example: mimicry and camouflage

OntogenyOntogeny• the developmental history of an organismthe developmental history of an organism• begins with embryogenesis, the development after fertilizationbegins with embryogenesis, the development after fertilization• includes post embryonic changes: aging or senescence and death.includes post embryonic changes: aging or senescence and death.• genes are the primary operantsgenes are the primary operants• a single lifetimea single lifetime

PhylogenyPhylogeny• the evolutionary history of group of speciesthe evolutionary history of group of species• it requires hundreds or thousands to hundred of millions of years.it requires hundreds or thousands to hundred of millions of years.

SymmetrySymmetry• refers to the arrangement of body parts in relation to the surrounding refers to the arrangement of body parts in relation to the surrounding

environment.environment.• radial, spherical, biradial and bilateral.radial, spherical, biradial and bilateral.

SegmentationSegmentation• refers to the regular repetition of body parts along the antero-posterior axis.refers to the regular repetition of body parts along the antero-posterior axis.• also known as metamerismalso known as metamerism• each unit is called a segment or metamere or somiteeach unit is called a segment or metamere or somite

CephalizationCephalization

• it refers to the centralization or localization of nervous structures with it refers to the centralization or localization of nervous structures with accompanying dominance of the head.accompanying dominance of the head.

• the pronounced tendency for the anterior end of the body to become more the pronounced tendency for the anterior end of the body to become more and more distinctly separated and differentiated from the rest of the and more distinctly separated and differentiated from the rest of the body=head.body=head.

• localization within the head the main part of the nervous system - i.e. the localization within the head the main part of the nervous system - i.e. the brain – and the most important sense organsbrain – and the most important sense organs

• it is more and more prominent as one ascends the animal kingdomit is more and more prominent as one ascends the animal kingdom

ReferencesReferences

Ching, J. Comparative Anatomy of Vertebrates Compendium. National Ching, J. Comparative Anatomy of Vertebrates Compendium. National Bookstore. 1Bookstore. 1stst ed. 2004. ed. 2004.

Hyman, L.H. Comparative Vertebrate Anatomy. The University Chicago Hyman, L.H. Comparative Vertebrate Anatomy. The University Chicago Press. 2Press. 2ndnd ed. 1963. ed. 1963.

Kardong, K. Vertebrates Comparative Anatomy, Function, and Evolution. Kardong, K. Vertebrates Comparative Anatomy, Function, and Evolution. McGraw-Hill.2McGraw-Hill.2ndnd ed. 1998. ed. 1998.

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