Comparative Anatomy of Vertebrates Presentation Lect 1

Comparative Anatomy of  Vertebrates Introduction: Terms, Terms, Concepts and History

Prepared by: Mr. Ian Kenneth M. Cabrera

Objectives • To know the common terminologies used in Comparative Anatomy

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

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

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

Meaning • Comparative Anatomy, but to be more accurately – comparative morphology, deals with the study of parts and structure stru cture (forms) and the structure corresponding functions of these forms of bodies of vertebrates

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• It is both descriptive and analytical. • The course also deals with the study of of natural history. Where did present 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 immutable complexity complexity like what we know now of them today? Did we really originate from apes?

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

The Tool The tool?

• of structures throws similarities and differences

Comparison.

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

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

Central Theme?

 Evolution of Characteristics

History of the Study: The People Responsible.

Carl von Linne also Carolus Linnaeus 17071778 –

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devised the binomial system of naming plants and animals which became the basis of  modern taxonomy.  published Systema Naturae argued that species were immutable immutable or unchangeable.

Jean Baptiste de Lamarck 1744-1829

• first to classify the animal kingdom into invertebrate and vertebrate

•  published Philosophie Zoologique • acquired characteristics and road to perfection

Georges Cuvier 1769-1832

• also argued that species are

immutable. • he stated that the design of each each animal could not have changed since creation. • organisms “must be understood as functional wholes because the  parts and the function they served were tightly related”. •  published a 22-volume masterpiece masterpiece –  Naturelle  Naturelle des  Poisons

Richard Owen 1804-1892

• developed concepts of homology and analogy • obtained and described the first good specimen of the primitive  bird Archaeopteryx which  provided evidence for the theory of evolution. • opposed the theory of evolution  by natural selection. • advocated the idea of the archetype, or ideal original  pattern, which served as a  blueprint for species.

Louis Agassiz 1807-1873

• Swiss-American paleontologist and geologist

•  published Studies on Glaciers • considered as the first teacher of  comparative anatomy

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

Charles Darwin 1809-1882

• developed the modern theory of 

evolution • 2 books – On the Origin of  Species and The Descent of Man •  based on his journey and travels on the HMS Beagle to the Galapagos islands in the Pacific ocean. • established the evolutionary basis, comparative, functional and adaptive morphology and anatomy. anatomy.

Alfred Russel Wallace 1823-1913 • developed the concept of survival of the fittest

Thomas Huxley

1825-1895

•  published Comparative Anatomy of Vertebrates in 1871

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

Terms and Concepts Homology • refers to features of two or o r more organisms sharing common ancestry • it also refers to the correspondence in type of structure between parts or  organs of different animals • clearly linked through time by continuity of fossil record • shown to develop similarity in the embryo from identical primordial. • different appearance, common general make-up example: the skeletons of the forelimbs fore limbs foreli mbs of cats, the wings of birds, the arms of humans, h umans, and the wings of a bat.

Analogy

• refers to features of two or o r more organisms sharing common function

• correspondence in function of a structure in similar or different organs or organ parts. example: the fin of a fish and the flipper of a whale the scales of fishes and reptiles Homoplasy

• refers to features of two oorr more organisms which may be related  by similarity of appearance but cannot be explained by either  homology and analogy. example: mimicry and camouflage

Ontogeny • the developmental history of an organism •  begins with embryogenesis, the development after fertilization • includes post embryonic changes: aging or senescence and death. • genes are the primary operants • a single lifetime Phylogeny • the evolutionary history of group of species • it requires hundreds or thousands to hundred of millions of years.

Symmetry • refers to the arrangement of body parts in relation to the surrounding environment. • radial, spherical, biradial and bilateral.

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

Cephalization

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

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

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

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

References Ching, J. Comparative Anatomy of Vertebrates Compendium. National Bookstore. 1st ed. 2004. Hyman, L.H. Comparative Vertebrate Anatomy. The University Chicago Press. 2nd ed. 1963. Kardong, K. Vertebrates Comparative Anatomy, Function, and Evolution. McGraw-Hill.2nd ed. 1998.

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