BIOLOGY Lection 6. Evolutionary biology First systematics of animals Aristotle (384-322 BC) Plato and Aristotle “Animals with Viviparous blood” (Vivipara) Cetaceans (Cetacea) Birds (Aves) Oviparous (Ovipara) Fishes (Pisces) “Animals without Soft-bodied blood” (Malacia) Soft-shelled (Malacostraca) Insects (Insecta) Armoured (Ostracoderma) Zoophytes (Zoophyta) Aristotle’s «Ladder of life» Humans Animals (with and without blood) Plants Minerals Making of hierarchic classification • Proposed the principle of hierarchic classification of plants and animals • Made the first (artificial) system of living organisms (“Systema Naturae”) • Gave a definition of the species • Introduced the binary nomenclature to determine the species Carolus Linnaeus • Creationist. Considered (1707-1778) species unchangeable Making of hierarchic classification Kingdom Subkingdom Division Phylum Class Order Family Offered by Linnaeus Genus Species «System of Nature» (1735) «System of Nature» of C. Linnaeus Kingdom Kingdom Kingdom Minerals Plants Animals (Lapideum) (Plantae) (Animalia) Class Mammals Class Birds Class Amphibians (incl. Class Fishes Reptiles) Class Insects (incl. Class Worms (most Spiders and Myriapods) invertebrates) First theory of evolution • Proposed the term "biology" and “invertebrate zoology" • Created the first theory of evolution. Its main statements: • "The use of the organ leads to its development, and the disuse – to its disappearance" • "Under the influence of exercise or Jean-Baptiste non-exercise the organs change Lamarck (1744-1829) and resulting changes are inherited" • The reason for the evolution was thought to be "inner desire for self-improvement of organisms" “Gradations” of J.-B. Lamarck 14. Mammals («Philosophy of Zoology», 1809) 13. Birds 12. Reptiles 11. Fishes 10. Mollusks 9. Cirripedians 8. Annelids Invertebrates 7. Crustaceans 6. Arachnids 5. Insects 4. Worms 3. Radiates 2. Polyps 1. Ciliates Homological and analogical organs Analogical organs – wings of insects and vertebrates Examples of homological organs Enamel Pulp Dentine Enamel Dentine Structure of placoid scales of shark and human tooth Examples of homological organs Middle ear bones and bones of lower jaw Examples of analogical organs Eye of fish and cephalopod mollusk Evolutionary theory of Charles Darwin Charles Darwin «The Origin of (1809-1882) Species…» (1859) Travel of «Beagle» (1831-1836) Types of variability after Darwin Variability of the beak shape in Galapagos finches 1. “Certain" (non-inherited, ~ modification) 2. “Uncertain" (inherited, ~ mutation) 3. Correlative (“White cats with blue eyes are deaf”) Geometric progression of reproduction Thomas-Robert Malthus (1766-1834) Main statements of Darwin’s theory • Geometric progression of reproduction results in a competition for resources • Its consequence - the struggle for existence (the diverse relations of species with each other and with environment) • The uncertain variability leads to benefit of some individuals over other ones • A consequence of the struggle for existence - natural selection (survival of the fittest), eliminating individuals with harmful changes • Evolution is an adaptive process • Divergence of characters within the species leads to speciation Speciation according to Darwin (principle of divergence) Proofs of evolution: rudiments Rudimentary hind limbs of boa Darwin’s tubercle Rudimentary hind limbs of whale Proofs of evolution: atavisms Human “tail” Hairy human Dolphin with 4 flippers Proofs of evolution: paleontology Mammal-like reptile Early amphibian First bird Archaeopteryx Sexual selection Examples of sexual dimorphism in animals Idea of “evolutionary tree” Ernst Haeckel (1834-1919) • The idea of "evolutionary tree" • Biogenetic law ("ontogenesis is the recapitulation of phylogeny") • The method of "evolutionary triad" Biogenetic law Embryonic development of vertebrates (after Haeckel).