Unformatted text preview: IB35ac Class 4: Evolution as Science
We can't talk about human evolution without addressing how religion comes into play with the science. Since evolution forms the basis for all of human biological variation, this lecture is dedicated to discussing why the study of evolution is science, and contrasting this with various other perspectives, especially creationism and intelligent design. IB35 Human Biological Variation Class #4 The skeleton is like scaffolding for other tissues and organs of the body. 206 bones Skull Postcranial skeleton Topics for today:
Skeletal anatomy Science & Evolution The Skull: Cranium Mandible Teeth Incisors (2) Canines (1) Premolars (2) Molars (3)
Incisors Canines Premolars Molars Tooth terminology: The Postcranial Skeleton: Clavicle & scapula Humerus Radius & ulna Carpals Metacarpals Phalanges Vertebral column Pelvis Femur Tibia & fibula Tibia & fibula Tarsals Metatarsals Phalanges Morphology:
Is the phenotypic character of an organism, or what it looks like (shape...) Remember... phenotype results from the b h l f h interaction between an organism's genotype and the organism's environment Phenotype: Observable characteristic of an organism 1 9/5/2009 Bones and teeth can tell you about: Size of the organism Age at death Health Locomotion Dietary habits Sources of Skeletal Variation...
2 main sources: Genes and Environment Growth (ontogeny) Geographic differentiation Geographic differentiation Sex Idiosyncrasy Individualizing Characteristic of person or group SHOVELING: Characteristic of incisors
GROWTH Dental Traits that Vary Geographically Dental Traits that Vary Geographically Cranial Traits That Are Informative of Ancestry Carabelli's Cusp
Heritable feature of molars 2 9/5/2009 Nasal bones Low and tented Highly arched, steeplelike Low and flat Tooth Eruption Chart: Nasal aperture medium Nasal sill Very sharp wide Dull or absent Growth (Ontogeny) Sexual Dimorphism
(Data are for the U.S.,19992002) Measured average height, weight, and waist circumference for adults ages 20 years and over Men: Height (inches): 69.3 Weight (pounds): 190 Waist circumference (inches): 39.0 Women: Height (inches): 63.8 Weight (pounds): 163 Waist circumference (inches): 36.5 510% size dimorphism in humans SEXUAL DIMORPHISM SEXUAL DIMORPHISM gorillas 3 9/5/2009 Sexual Dimorphism Sexual Dimorphism Idiosyncrasy Idiosyncrasy A B C Photo credit: http://www.uni regensburg.de/Fakultaeten/phil_Fak_II/Psychologie/Psy_II/beautycheck/english/symmetrie/symmetrie.htm The Controversy of Evolution Before Darwin variation is just "noise" Teleology (order is inherent) A static world A static world JeanBaptiste Lamarck 17441829 French anatomist Mechanism of evolution: inheritance of acquired characteristics (use and disuse of body parts) Progressive evolution Hereditary plasticity Jean Baptiste de Lamarck Transmutation Teleological Altering of one species into another Philosophical study of design and purpose the degree to which an organism's genotype is dependent on hereditary characteristics 4 9/5/2009 Teleology "A teleological explanation is one that explains the existence of occurrence of something by citing a goal or purpose that is served by the thing... g There is no argument about the teleos of a hammer... But where does the series of "why" questions stop?" (from Daniel Dennett's 1995 Darwin's Dangerous Idea, p.24) Evolution by Natural Selection Transmutation/evolution was not new Theory of evolution BY NATURAL SELECTION was new Selection by the environment brings order out of randomness (accumulation of design) Natural selection answers the "why" question of l l h " h " f evolution Another important point: The individual is the most important unit of biological change Another important point: Variation among individuals is essential What Darwin Actually Said Proposed a testable hypothesis Darwin writes 14 chapters trying to demonstrate that evolution by natural selection didn't happen, but comes to the conclusion that all the data he compiled can't refute this idea. Prelude to the Scopes Trial Summer for the Gods, by Edward J. Larson March 1925, Tennessee's Butler Act is passed ACLU offered to defend anyone willing to teach evolution in defiance of this law h l i i d fi f hi l City of Dayton (pop. 1,756), looking for publicity John Scopes indicted in April of 1925 The Scopes Trial Prosecution brings in William Jennings Bryan Defense then brings in Clarence Darrow Bryan's view on evolution Darwinism undermined morality Vernon Kellogg, 1917, Headquarters Nights: A Record of Conversations and Experiences at the Headquarters of the German Army in the Headquarters of the German Army in Belgium and France Benjamin Kidd, 1918, The Science of Power James Leuba, 1916, The Belief in God and Immortality 5 9/5/2009 Herbert Spencer 1864 Principles of Biology Coined "survival of the fittest" The "Moral" Problem Posed by Darwin Evolution by natural selection provides no clues for human conduct or moral dilemmas People find comfort in order and purpose But he really applied a Lamarckian sense of evolution to sociology rather than natural selection Does Evolution Make us Immoral?
"... the ethical progress of society depends, not on imitating [nature], still less in running away from it, but in combating it." T. H. Huxley The essence of a scientific proposition is that is can be tested by observation observation. From: http://www.ncseweb.org/graphics/continuum.gif 6 ...
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