Chapter 15 Exploring Biological Diversity Lecture Outline PDF

Because learning changes everything. ® Chapter 15 Exploring Biological Diversity Lecture Outline Essentials of the Living World Seventh Edition George Johnson, Joel Bergh © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGra...

Because learning changes everything. ® Chapter 15 Exploring Biological Diversity Lecture Outline Essentials of the Living World Seventh Edition George Johnson, Joel Bergh © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC.  15.1 The Invention of the Linnaean System 1 To talk about and to study organisms, it is necessary to give them names. Biologists use a kind of multilevel grouping of individuals called classification. The earliest classification scheme grouped animals and plants into basic units called genera (singular, genus). © McGraw Hill, LLC 2  15.1 The Invention of the Linnaean System 2 Today’s universal system for naming and classifying organisms was developed by Carolus Linnaeus. Linnaeus assigned organisms a two-part name called a binomial. He also grouped similar organisms into higher-level categories based on similar characteristics. © McGraw Hill, LLC 3  Figure 15.1: Carolus Linnaeus (1707 to 1778) Time & Life Pictures/Getty Images © McGraw Hill, LLC 4  15.2 Species Names 1 Taxon (plural, taxa) is a group of organisms at a particular level in a classification system. The branch of biology that identifies and names such groups is called taxonomy. No two kinds of organisms can have the same name and all names are given in Latin. © McGraw Hill, LLC 5  15.2 Species Names 2 The scientific name or species name for an organism is comprised of the two-part binomial. The first part is the genus, which is always capitalized. The second part refers to the particular species, and is not capitalized. The two words together are written in italics or are underlined. © McGraw Hill, LLC 6  15.3 Higher Categories The binomial has been expanded into a Linnaean system of classification. Domain. Kingdom. Phylum (pl. phyla). Class. Order. Family. Genus (pl. genera). Species (pl. species). © McGraw Hill, LLC 7  15.4 What Is a Species? 1 The basic biological unit is the species. All the individuals that belong to it can breed with one another and produce fertile offspring. The Biological Species Concept defines species as groups that are reproductively isolated. Works well for animals, but not as well for organisms in which asexual reproduction is more common. © McGraw Hill, LLC 8  15.4 What Is a Species? 2 The biological species concept is not always employed for plants and other organisms. Molecular data are causing a reevaluation of traditional classification systems. Since the time of Linnaeus, about 1.5 million species have been named. The actual number of species is much greater. © McGraw Hill, LLC 9  15.5 How to Build a Family Tree 1 Phylogeny is the evolutionary history of an organism and its relationship to other species. Scientists use different approaches to construct phylogenetic trees. © McGraw Hill, LLC 10  15.5 How to Build a Family Tree 2 Cladistics is an approach that infers phylogeny according to similarities. Derived characters are characters that are present in a group of organisms that arose from an ancestor that lacked the character. A clade is a group of organisms, related by descent, that share a derived character. By examining the distribution of derived traits among related organisms, it is possible to construct a cladogram, a branching diagram that represents the phylogeny. © McGraw Hill, LLC 11  Figure 15.6: A cladogram of vertebrate animals Access the text alternative for slide images. © McGraw Hill, LLC 12  15.5 How to Build a Family Tree 4 An alternative approach to constructing phylogenies is traditional taxonomy. A great deal of information about the morphology and biology of an organism is used. © McGraw Hill, LLC 13  Figure 15.7: Two ways to classify terrestrial vertebrates Access the text alternative for slide images. © McGraw Hill, LLC 14  15.6 The Kingdoms of Life Most biologists use a six-kingdom classification system first proposed by Carl Woese. Four kingdoms consist of eukaryotes. Animalia, Plantae, Fungi, and Protista. Two kingdoms consist of prokaryotes. Archaea and Bacteria. Recognizing that there are further differences among the prokaryotes, the domain level above kingdom was created. Domain Archaea contains the Kingdom Archaea. Domain Bacteria contains the Kingdom Bacteria. Domain Eukarya contains the eukaryotic kingdoms. © McGraw Hill, LLC 15  15.7 Domain: A Higher Level of Classification 1 Bacteria are the most abundant organisms on earth. There are many different types of bacteria and the evolutionary links between them are not well understood. Many species of bacteria play critical roles throughout the biosphere. Although Archaea are also prokaryotic like bacteria, the Archaea are more closely related to eukaryotes. © McGraw Hill, LLC 16  15.7 Domain: A Higher Level of Classification 2 Archaea, although a diverse group, share certain key characteristics. They possess unique cell walls, lipids, and rRNA sequences. Some genes in the archaea have introns. Archaea are often found in extreme environments but are not restricted to them. © McGraw Hill, LLC 17  15.7 Domain: A Higher Level of Classification 3 Eukaryotes appeared about 1.5 billion years ago. There are three largely multicellular kingdoms (fungi, plants, and animals). The remaining eukaryotic kingdom, Protista, is a diverse array of mostly unicellular forms that basically don’t fit into the other kingdoms. © McGraw Hill, LLC 18  15.7 Domain: A Higher Level of Classification 4 Mitochondria and chloroplasts are both believed to have been derived from bacteria that entered early eukaryotic cells by endosymbiosis. Figure 15.12 Endosymbiosis © McGraw Hill, LLC 19  Table 15.1: Characteristics of the Six Kingdoms 1 Domain Bacteria Archaea Eukarya Kingdom Bacteria Archaea Protista Plantae Fungi Animalia An illustration shows a bacteria. An illustration shows Archaea. An illustration shows a Protista. An illustration shows a tree. An illustration shows a mushroom. An illustration shows a bird. Cell type Prokaryotic Prokaryotic Eukaryotic Eukaryotic Eukaryotic Eukaryotic Nuclear Absent Absent Present Present Present Present envelope Mitochondria Absent Absent Present or Present Present or Present absent absent Chloroplasts None None Present in some Present Absent Absent (photosynthetic (bacteriorhodopsi forms membranes in n in one species) some types) Cell wall Present in most; Present in most; Present in some Cellulose and other Chitin and other Absent peptidoglycan polysaccharide, forms; various polysaccharides noncellulose glycoprotein, or types polysaccharides protein © McGraw Hill, LLC 20  Table 15.1: Characteristics of the Six Kingdoms 2 Domain Bacteria Archaea Eukarya Kingdom Bacteria Archaea Protista Plantae Fungi Animalia Means of Conjugation, Conjugation, Fertilization and Fertilization and Fertilization and Fertilization genetic transduction, transduction, meiosis meiosis meiosis and meiosis recombination transformation transformation , if present Mode of Autotrophic Autotrophic Photosynthetic or Photosynthetic, Absorption Digestion nutrition (chemosynthetic, (photosynthesis heterotrophic or chlorophylls a and b photosynthetic) or in one species) combination of heterotrophic or heterotrophic both Motility Bacterial flagella, Unique flagella in 9 + 2 cilia and None in most Nonmotile 9 + 2 cilia gliding, or some flagella; forms, 9 + 2 cilia and flagella, nonmotile amoeboid, and flagella in contractile contractile fibrils gametes of some fibrils forms Multicellularity Absent Absent Absent in most Present in all forms Present in most Present in all forms forms forms © McGraw Hill, LLC 21