1、Animal classification and systematics,Criteria for classifying animalsArtificial classification an arrangement that is based on convenient or arbitrary attribution, not expressing the true natural relations among species based on the purpose of usage oil plants spiceberry plants textile plants based
2、 on superficial characters,Natural classificationExtant organisms are a product of evolution for a long time there are different degrees of relatedness among speciesSystematics / taxonomy the study of the kinds and diversity of organisms and of the evolutionary relationship among themIt takes into a
3、ccount similarities and differences between organismsArranging organisms into a order that may adequately reflect evolutionary relationship among them,Methods of natural classificationClassical taxonomy: morphological characters External morphology flower, seed, feather Internal structure comparativ
4、e anatomy Developmental pattern early embryonic stages of vertebrates are remarkably similar. The similarities are compelling evidence of evolutionary relationship within animal groups 重演律/生物发生律 Ecology and behavior nesting, singing, displaying,Modern taxonomy cytology karyotypes 染色体组型 banding patte
5、rns of chromosome 染色体分带 immune reaction structure and function of macromolecules genes proteinsWhen zoologists classify animals into taxonomic groupings, they are making hypotheses about the extent to which groups of animals share genes and proteins,Structure and function of macromolecules Inouye 同工
6、酶 sequencing of amino acids in proteins cytochrome c a kind of conserved protein, which has changed so little during hundreds of millions of years sequencing of the mitochondrial DNA sequencing of the nuclear DNA,Phylogeny 系统发生 evolutionary relationships among species or higher taxaMolecular phyloge
7、netics evolution of biological large molecules, Biological large molecules have relatively constant rates of change over time Different molecules, different genes within the same genome, or different regions of DNA have different rates of change The distributions of gene families may reflect evoluti
8、onary relationship among speciesMolecular clock the amount of change in a region of molecules can be used to date evolutionary events and provide estimates of time elapsed since divergence from a common ancestor,Mitochondrial DNA widely used in studying taxonomic relationshipsMitochondria have their
9、 genetic systems and are inherited cytoplamicallyTherefore, mitochondria are transmitted from parent to offspring through the egg cytoplasm and can be used to trace maternal lineages, Nuclear DNA Ribosomal RNA 核糖体RNA Protein,1Microtubule hollow cylinders Basic unit: three types of tubulins 微管蛋白 ,and
10、 ,Molecular techniques will not replace traditional taxonomic methods,Taxonomic hierarchy1735, Linns two-kingdom system Plantae, Animalia1866，Haeckels three-kingdom system Protista, Plantae, Animalia1969，Whittakers five-kingdom Monera, Protista, Plantae, Fungi, Animalia1980，Woese and Foxs three-doma
11、in system Archaea, Eubacteria, Eukarya,Whittakers five-kingdom classification system,Animalia,Protozoa 原生动物门 Spongia 海绵动物门 Coelenterata 腔肠动物门 Platyhelminthes 扁形动门 Protocoelomata原腔动物门 Annelida 环节动物门 Mol1usca 软体动物门 Arthropoda 节肢动物门 Echinodermata 棘皮动物门 Chordata 脊索动物门,Ancient archaeans 古细菌 “the third fo
12、rm of life” live in extreme conditions, such as high temperature, high salt or high acidic environments show great differences from true bacteria in physiology, biochemistry and molecular mechanism The anaerobic 缺氧的 environments may reflect the conditions on the earth at the time of lifes origin,Bas
13、ed on studies of ribosomal RNA, Woese and Fox (1980, 1990) separated ancient archaeans from true bacteria and suggested a three-domain classification system Archaea 古细菌主群，古核生物 Eubacteria 真细菌主群，原核生物 Eukarya 真核生物主群，真核生物,Taxonomic hierarchy Domain 域 Eukarya 真核 Kingdom界 Animalia 动物界 Phylum 门 Chordata 脊索
14、动物门 脊椎动物亚门 Class 纲 Mammalia 哺乳纲 真兽亚纲 Order 目 Primates 灵长目 类人猿亚目 Class 科 Hominidae 人科 Genus 属 Homo 人属 Species 种 Sapiens 人种,Concept of species and nomenclature1Definition for species The modern definition of species does not mention morphological similarities and focuses on reproductive ability A spec
15、ies is defined as a group of organisms that shares the same gene pool and are capable of interbreeding in the wild to produce fertile offspring物种是能够或可能相互配育的自然种群的类群，这些类群与其它类群在生殖上是相互隔离的, Only the species objectively exists in nature The species is a basic unit of evolution, and the fundamental unit of
16、 biological classification Modern species concept emphasizes the importance of population as a evolutionary unit,Numbers of species 287,655 plants, including: 15,000 mosses 13,025 ferns 980 gymnosperms 199,350 dicotyledons 59,300 monocotyledons 74,000-120,000 fungi 10,000 lichens 1,250,000 animals,
17、including: 1,190,200 invertebrates 50,000 insects 70,000 mollusks 40,000 crustaceans 130,200 others 58,808 vertebrates: 29,300 fish 5,743 amphibians 8,240 reptiles, 10,234 birds, (9799 extant as of 2006) 5,416 mammalsHowever, the total number of species for some phyla may be much higher: 5-10 millio
18、n bacteria; 1.5 million fungi,NomenclatureBinomial system originally established byKarl von Linn (1707-1778) 300 years ago A two-part name, treated as Latin and printed in italics, describes each kind of organism, which is recognized throughout the worldgenus name + species name 主格单数名词 形容词或名词（表示主要特征
19、或产地）, Colon bacillus 大肠杆菌 Escherichid coliWhite eared pheasant 白马鸡 Crossiptilon crossoptilon Tibetan eared pheasant 藏马鸡 C. harmani Blue eared pheasant 蓝马鸡 C. auritum Brown eared pheasant 褐马鸡 C. mantchuricum,2Subspeciesgenus name + species name + subspecies nameBlackbird 乌鸫 Turdus merula maximus,病毒1. 进化地位：尚未确定(1) 原始的生命形态？(2) 起源于有细胞结构的生物，由于专性寄生，逐渐失去细胞结构？(3) 细胞中的一部分遗传物质，脱离了细胞？,病毒的结构 a 体积小：在电子显微镜下才能看到 b 形状各异：大多数球形、多面体，少数杆状、砖块状、蝌蚪状蛋白质外壳（衣壳）+ 一个核酸芯子（核髓）,病毒的类别已知约6000余个个类别 噬菌体3000余个，动植物3000余个根据病毒粒子的外形、蛋白质衣壳的形态结构、核酸的类型对病毒分类和命名也有根据宿主类型、所引起的疾病、传播方式命名,
