CAMPBELL BIOLOGY IN FOCUS © 2014 Pearson Education, Inc. Urry Cain Wasserman Minorsky Jackson Reece Lecture Presentations by Kathleen Fitzpatrick and Nicole Tunbridge 24 Early Life and the Diversification of Prokaryotes

© 2014 Pearson Education, Inc. Figure 24.1

© 2014 Pearson Education, Inc. Fig. 20-1a, p.318 Looking for Life in All the Odd Places

© 2014 Pearson Education, Inc. Fig. 20-1b, p.318 Looking for Life in All the Odd Places

© 2014 Pearson Education, Inc. Fig. 20-3, p.320 The Big Bang

© 2014 Pearson Education, Inc. First Atmosphere Hydrogen, Methane, Ammonia, Nitrogen, CO, CO 2 and so on No gaseous O 2

© 2014 Pearson Education, Inc. Fig. 20-4b, p.321 First Atmosphere

© 2014 Pearson Education, Inc. Origin of Organic Compounds Oparin ’ s Hypothesis organic compounds and eventually life form spontaneously under early Earth conditions (Organic soup) Recent - Clay may have acted as catalyst for complex compounds

© 2014 Pearson Education, Inc. to vacuum pump CH 4 NH 3 H 2 O H 2 gases electrodes spark discharge water out condenser water in water droplets water containing organic compounds liquid water in trap boiling water Fig. 20-4c, p.321 Stanley Miller’s Experiment

© 2014 Pearson Education, Inc. RNA World DNA-to-RNA-to-protein system is complicated RNA first ? RNA can assemble spontaneously How switch from RNA to DNA might have occurred is not known

© 2014 Pearson Education, Inc. Proto-Cells Proteins and lipids self assemble into microscopic spheres in water Nanobes may resemble proto-cells

© 2014 Pearson Education, Inc. Fig. 20-6b, p.322 Proto-Cells

© 2014 Pearson Education, Inc. Fig. 20-6c, p.322 Proto-Cells

© 2014 Pearson Education, Inc. living cells formation of protein-RNA systems, evolution of DNA formation of lipid spheres spontaneous formation of lipids, carbohydrates, amino acids, proteins, nucleotides under abiotic conditions membrane-bound proto-cells self-replicating system enclosed in a selectively permeable, protective lipid sphere DNARNA enzymes and other proteins Stepped Art Fig. 20-7c, p.323 Possible Sequence

© 2014 Pearson Education, Inc. Fig. 20-8a, p.324 Prokaryotes

© 2014 Pearson Education, Inc. Fig. 20-8c, p.324 Prokaryotes

© 2014 Pearson Education, Inc. Fig. 20-7, p.324 Prokaryotes

© 2014 Pearson Education, Inc. Fig. 20-8b, p.324 Eukaryotes

© 2014 Pearson Education, Inc. Stromatolites

© 2014 Pearson Education, Inc. Fig. 20-9b, p.325 Eukaryotes

© 2014 Pearson Education, Inc. Fig. 20-9c, p.325 Eukaryotes

© 2014 Pearson Education, Inc. Theory of Endosymbiosis Lynn Margulis Prokaryotes were engulfed (eaten?) and became permanent internal symbionts

© 2014 Pearson Education, Inc. nucleus mitochondrion photosynthetic organelle that resembles a cyanobacterium Fig b, p.327 Theory of Endosymbiosis

© 2014 Pearson Education, Inc. 17 Viruses Viruses

© 2014 Pearson Education, Inc. Figure  m

© 2014 Pearson Education, Inc. virus structure Viruses - a nucleic acid enclosed in a protein capsid may contain Double- or single-stranded DNA, or RNA with reverse transcriptase Each virus has a limited host range

© 2014 Pearson Education, Inc. Figure 17.2 RNA Capsomere of capsid Glycoproteins Capsomere Membranous envelope RNA Capsid Head DNA Tail sheath Tail fiber Glycoprotein 80  225 nm 80–200 nm (diameter) 70–90 nm (diameter) 18  250 nm (a) Tobacco mosaic virus 20 nm (b) Adenoviruses 50 nm (c) Influenza viruses 50 nm (d) Bacteriophage T4 50 nm

© 2014 Pearson Education, Inc. Figure 17.3 VIRUS Replication Entry and uncoating DNA Capsid Transcription and manufacture of capsid proteins HOST CELL Viral DNA mRNA Capsid proteins Self-assembly of new virus particles and their exit from the cell

© 2014 Pearson Education, Inc. Replicative Cycles of Phages two reproductive mechanisms: the lytic cycle and the lysogenic cycle

© 2014 Pearson Education, Inc. The Lytic Cycle lytic cycle - produces new phages and lyses (breaks open) the host’s cell, releasing new viruses A phage that reproduces only by the lytic cycle is called a virulent phage Animation: Phage T4 Lytic Cycle

© 2014 Pearson Education, Inc. Figure Attachment 1

© 2014 Pearson Education, Inc. Figure Attachment 1 Entry of phage DNA and degradation of host DNA 2

© 2014 Pearson Education, Inc. Figure Attachment 1 Entry of phage DNA and degradation of host DNA 2 Synthesis of viral genomes and proteins 3

© 2014 Pearson Education, Inc. Figure Attachment 1 Entry of phage DNA and degradation of host DNA 2 Synthesis of viral genomes and proteins 3 Assembly Phage assembly Head Tail Tail fibers 4

© 2014 Pearson Education, Inc. Figure Attachment 1 Entry of phage DNA and degradation of host DNA 2 Synthesis of viral genomes and proteins 3 Assembly Phage assembly Head Tail Tail fibers 4 Release 5

© 2014 Pearson Education, Inc. The Lysogenic Cycle lysogenic cycle – replicates phage genome without destroying the host Phages that use both the lytic and lysogenic cycles are called temperate phages environmental signal can trigger a switch to the lytic mode

© 2014 Pearson Education, Inc. Figure 17.5 The phage injects its DNA. Daughter cell with prophage Many cell divisions create many infected bacteria. Prophage is copied with bacterial chromosome. Phage DNA integrates into bacterial chromosome. Phage DNA and proteins are synthesized and assembled. The cell lyses, releasing phages. Lytic cycleLysogenic cycle Prophage exits chromosome. Phage DNA circularizes. Phage DNA Phage Bacterial chromosome Prophage

© 2014 Pearson Education, Inc. RNA as Viral Genetic Material Retroviruses use reverse transcriptase to copy their RNA genome into DNA HIV (human immunodeficiency virus) is the retrovirus that causes AIDS (acquired immunodeficiency syndrome)

© 2014 Pearson Education, Inc. Figure 17.7 Reverse transcriptase HIV Glycoprotein Viral envelope Capsid RNA (two identical strands) HOST CELL Reverse transcriptase Viral RNA RNA-DNA hybrid DNA NUCLEUS Chromosomal DNA RNA genome for the next viral generation mRNA HIV Membrane of white blood cell HIV entering a cell 0.25  m Provirus New virus New HIV leaving a cell

© 2014 Pearson Education, Inc. Vaccine - a harmless pathogen derivative that stimulates an immune system response

© 2014 Pearson Education, Inc. Figure 17.8 (a) 2009 pandemic H1N1 influenza A virus (b) 2009 pandemic screening 1  m

© 2014 Pearson Education, Inc. Figure 17.UN01

© 2014 Pearson Education, Inc. 20 Phylogeny Phylogeny

© 2014 Pearson Education, Inc. Phylogeny - evolutionary history of a species or group systematics classifies organisms and determines evolutionary relationships Taxonomy is the ordered division and naming of organisms

© 2014 Pearson Education, Inc. Binomial Nomenclature In the 18th century, Carolus Linnaeus published system of taxonomy based on resemblances (Linnaean system)

© 2014 Pearson Education, Inc. Binomial Nomenclature Binomial Nomenclature - 2 name naming system The Scientific name (Binomial) is the Genus name followed by the species name Genus name starts with a capital letter the rest is lower case Species name is never written without at least the first initial of the genus name Binomials are written in italics (or a contrasting writing style) Binomials are Latin or “ Latinized ”

© 2014 Pearson Education, Inc. Taxonomy Domain (Largest and Most General) Kingdom Phylum Class Order Family Genus Species (Smallest and Most Specific)

© 2014 Pearson Education, Inc. Taxonomy Inbetween levels are used where necessary Kingdom Subkingdom Superphylum Phylum Subphylum Superclass Class Subclass Superorder…and so on….

© 2014 Pearson Education, Inc. Figure 20.3 Species: Panthera pardus Kingdom: Animalia Domain: Archaea Domain: Bacteria Domain: Eukarya Genus: Panthera Order: Carnivora Family: Felidae Class: Mammalia Phylum: Chordata

© 2014 Pearson Education, Inc. Linking Classification and Phylogeny Systematists depict evolutionary relationships in branching phylogenetic trees

© 2014 Pearson Education, Inc. Figure 20.4 Panthera pardus (leopard) Species Order FamilyGenus Taxidea taxus (American badger) Canis latrans (coyote) Lutra lutra (European otter) Canis lupus (gray wolf) Panthera Taxidea Canis Lutra Felidae Mustelidae Carnivora Canidae 12

© 2014 Pearson Education, Inc. A phylogenetic tree represents a hypothesis about evolutionary relationships Each branch point (node) represents the divergence of two taxa Sister taxa are groups that share an immediate common ancestor

© 2014 Pearson Education, Inc. Figure Branch point: where lineages diverge This branch point represents the common ancestor of taxa A−G. This branch point forms a polytomy: an unresolved pattern of divergence. ANCESTRAL LINEAGE Sister taxa Basal taxon Taxon A Taxon B Taxon C Taxon D Taxon E Taxon F Taxon G

© 2014 Pearson Education, Inc. Cladistics Cladistics classifies organisms by common descent A clade is a group of species that includes an ancestral species and all its descendants

© 2014 Pearson Education, Inc. A valid clade is monophyletic, signifying that it consists of the ancestor species and all its descendants

© 2014 Pearson Education, Inc. Figure 20.10a B C A D E F G Group I (a) Monophyletic group (clade) 1

© 2014 Pearson Education, Inc. A paraphyletic grouping consists of an ancestral species and some, but not all, of the descendants

© 2014 Pearson Education, Inc. Figure 20.10b B C A D E F G Group II (b) Paraphyletic group 2

© 2014 Pearson Education, Inc. A polyphyletic grouping consists of various taxa with different ancestors

© 2014 Pearson Education, Inc. Figure 20.10c (c) Polyphyletic group B C A D E F G Group III 1 2

© 2014 Pearson Education, Inc. Figure 20.11b Leopard Turtle Frog Bass Lamprey Lancelet (outgroup) Hair Amnion Four walking legs Hinged jaws Vertebral column (b) Phylogenetic tree

© 2014 Pearson Education, Inc. Figure Forams Ciliates Euglenozoans Diatoms COMMON ANCESTOR OF ALL LIFE Land plants Animals Amoebas Fungi Red algae Chlamydias Green algae (Mitochondria)* Methanogens Proteobacteria Nanoarchaeotes Thermophiles Domain Eukarya Gram-positive bacteria (Chloroplasts)* Spirochetes Cyanobacteria Domain Bacteria Domain Archaea

© 2014 Pearson Education, Inc. Figure 20.2 ANCESTRAL LIZARD (with limbs) Eastern glass lizard Monitor lizard Snakes Geckos No limbs Iguanas No limbs