Five Kingdoms. What is botany? 2 Kingdom System of Classification: Plants & Animals (Linnaeus, ~1750) Three Domains. The land plant Divisions

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1 What is botany? 2 Kingdom System of Classification: Plants & Animals (Linnaeus, ~1750) Five Kingdoms 5 Kingdom System: Monera, Protista, Plantae, Fungi, Animalia (Robert Whittaker, 1969) 3 Domain System: Bacteria, Archaea, Eukarya (our current best hypothesis) What does this timeline illustrate about the process of science? Three Domains The land plant Divisions Gymnosperms Bryophytes Red 150 mya Angiosperms 280 mya Ferns 400 mya 750 mya Green Brown Protists What is botany? Short answer: the study of plants (Kingdom Plantae, in Domain Eukarya) For Bio 1C: the study of Kingdoms Plantae, Fungi, Protista, and some photosynthetic members of Domain Bacteria What is Ecology? The scientific study of the interactions between organisms and their environments is called ecology provides a basic understanding of how natural processes and organisms interact, gives us the tools we need to manage the planet s limited resources over the long term 1

2 Major Components of the Environment Abiotic components, which consist of nonliving chemical and physical factors, such as temperature, light, water, minerals, and air Biotic components, which include the living factors all the other organisms that are part of an individual s environment. Hierarchy of Interactions We can divide ecology into four increasingly comprehensive levels: organismal ecology, population ecology, community ecology, and ecosystem ecology Life on Earth - Timescale The land plant Divisions 3.4 BYA - heterotrophs BYA O 2 begins to Accumulate 2.2 BYA first Eukaryotes 700 MYA sharp increase in Atmospheric O 2. Reached modern levels in Cambrian MYA 450 MYA life on oceans surface and on to land Gymnosperms Bryophytes Red 150 mya Angiosperms 280 mya Ferns 400 mya 750 mya Green Brown Protists The changing earth: The Origin of Life Early Earth was a very different place than it is now. Chemically reactive atmosphere Very little Oxygen Very High UV and other energy sources (UV damages DNA/RNA) Fig

3 Pasteur and biogenesis of microorganisms (Layer 3) Pasteur 1850s Spontaneous Generation vs. Biogenesis So How did Life Originate? Four Stage Hypothesis 1. Abiotic synthesis of Organic Monomers (the building blocks) 2. Abiotic Synthesis of Polymers, including amino acids and nucleic acids. 3. Formation of Pre-cells or protobionts: droplets with membranes that maintained an internal chemistry distinct from their surroundings. 4. Self replecating molecules arose, making inheritance possible Origin of Life experiments Miller-Urey Tested for Synthesis of Organic Monomers Got all 20 amino acids, sugars, lipids, nucleotides, even ATP! The Miller-Urey experiment: 1953 Deep sea hydrothermal vents could also have played a role Producing organic polymers:dripping monomers onto hot sand, clay or rock. Stage 4- Laboratory versions of Protobionts or Pre-cells Conditions existed near active volcanoes and deep sea vents 3

4 Lynn Margulis: serial endosymbiosis Origin of Eukaryotic Cells Single Celled to Multicelled What is an adaptation? From an evolutionary perspective: An adaptation is any trait or feature of an organism that increases its chances of reproducing. From an interpretive perspective: An adaptation is any structure or mechanism exhibited by an individual species that allows it to meet its physiological requirements under the conditions posed by a particular habitat. Some adaptations Adaptations to live near shore (algae) to take advantage of nutrients Transitioning to land means need water! Animals move, Fungi live underground (essentially) Plants developed specialized tissue systems The vascular system in plants Protected gametophytes Linnaeus: 1750 s Binomial nomenclature 4

5 Taxonomy Three members of the violet genus Viola. They differ in features due to local adaptations, but there is an overall similarity. This genus has about 500 species Five Kingdoms Three Domains R.H Whittaker 1969 Cladistics: Cladograms and molecular data Evolutionary Trees What are the tools used by scientists to observe and understand evolutionary relationships? 1. Artificial selection 2. Fossil record 3. Comparative anatomy 4. Comparative embryology 5. Comparative biochemistry 6. Biogeography 5

6 What about analogous structures? Convergent evolution Co-evolution Some major episodes in the history of life Systematics: connecting phylogeny and taxonomy Taxonomy = the science of classifying organisms Figure 25.8 Taxonomy starts with the latin binomial, and exhibits a hierarchical structure reflecting phylogenetic relationships among taxa or groups of organisms Latin binomial or two-part name (genus and species) Phylogenetics = the study of phylogeny, or the history of evolutionary relationships among species Figure 25.9 The connection between classification and phylogeny: this phylogenetic tree organizes taxa into a hypothesized tree of evolutionary relatedness, with species at the tips of the branches. How are these phylogenetic trees constructed? Traditional Approach: Phenetics Classifications based on perceived overall similarity 6