Evolution = change over generations Change Over Time Evolution = change over generations

4.1 A Page 75

A. Origin of Life Abiogenesis: idea that life came from nonliving material, also called spontaneous generation Early Atmosphere Consisted of gases like carbon monoxide, nitrogen, and carbon dioxide NO OXYGEN

Oparin Developed theory that inorganic molecules could become organic molecules due to early conditions of earth- carbon monoxide, carbon dioxide and nitrogen (NO OXYGEN)

Miller and Urey: Created experiment that tested early earth conditions and observed formation of organic molecules (proteins)

Biogenesis Life now continues Life began from abiogenesis and continues through biogenesis

Redi and Pasteur Both scientists used experiments to disprove that BIOGENESIS occurs now. Life now comes from living things (even microscopic), not from the air itself.

Redi and Pasteur

B. Evolution of Cells – mutations produced new varieties of cells that co-exist. Heterotroph Hypothesis- the first cells lacked complexity and could NOT make their own food First Cell: (3.5 bya) were prokaryotic, anaerobic due to lack of oxygen in atmosphere, and heterotrophic = consumed food

B. Evolution of Cells Second cell: prokaryotic, anaerobic, photosynthetic (but produced OXYGEN) Third Cell: aerobic prokaryotic; atmosphere now filled with oxygen due to photosynthesizing prokaryotic cells

B. Evolution of Cells Endosymbiont Theory- Explains the evolution of eukaryotic cells by smaller cells living together Aerobic prokaryotes became mitochondria Photosynthetic prokaryotes became chloroplast Evidence -> chloroplast and mitochondria are the only organelles with their own DNA!

Videos and Animations Early Earth animation -- https://www.youtube.com/watch?v=GP0HT77OPYQ Endosymbiont Theory Animation – https://www.youtube.com/watch?v=_xGTTw98Xa0

C. Theory of Evolution pg. 77 Charles Darwin: Naturalist; credited with theory of evolution; sailed on the Beagle in 1831 Natural Selection: organisms from a population are selected to survive because they are best adapted to the current environment – can cause new species (speciation)

Natural Selection- a process 1) Variation: members of the population are genetically different, and therefore have different phenotypes 2) Overproduction: more members of the population exist than the carrying capacity can support 3) Competition: favors the best suited phenotype at that particular time. 4) Survival of best adapted: success is measured by the ability to pass on genes in REPRODUCTION

Adaptations: inherited trait that helps organism survive in environment and mate Structural: any physical form or part, such as beak shape for a bird, or mimicry Mimicry- similarity of one species to another which protects one or both Example: King Cobra and Coral Snake, Stick Bug

Adaptations Behavioral: any genetically-controlled action; Example- herding, growling Physiological: any body process; Example-oxygen binding to hemoglobin

4.1 D – pg. 78

D. Evidence for Evolution pg.78 1. Fossils: any evidence of life that once existed on earth (bones, footprints, etc); Shows patterns of evolution over time

Fossil Cont. Relative Dating - Order of appearance in sedimentary rock Radioactive Dating Use the natural decay of isotopes in organism

Evidence for Evolution cont… 2. Biochemical Similarities : comparing DNA, RNA or amino acid sequences in proteins the more similar more closely related

3. Anatomical Structures- body Evidence for Evolution cont… 3. Anatomical Structures- body Homologous: similar structure different function, evidence of common ancestor

Anatomical Structures cont… Analogous: same function, different structure; evidence of common environment Example: bird wing and butterfly wing

Anatomical Structures cont… Vestigial: currently serve no purpose in organism, may be “left over” from previous ancestor. Ex – wisdom teeth, appendix

4.1 E page 79

Mechanisms for Evolution:4.1 E page 79 POPULATIONS evolve; individuals do not. Population is the smallest unit of evolution Different versions of acquired traits are present in a population and can be selected thus changing the population

Mechanisms for Evolution 2. Changes in Gene Pool: 1. Mutations: changes in the DNA of an organism - Does the change affects the phenotype?

Mechanisms for Evolution 2. Environmental changes: Types of natural selection Disruptive – conditions are most favorable for BOTH of the two extremes of the phenotype Stabilizing – conditions are most favorable for the average version of the phenotype Directional – conditions are most favorable for ONE of the two extremes of the phenotype

Stabilizing Selection Before Disruptive Selection Before After Stabilizing Selection Before After Directional Selection Before After

Mechanisms for Evolution 3. Speciation - development of a new species Geographic Isolation – part of population becomes separated by distance, and evolves differently  this leading to a new species

Timeframe for Evolution Timeframes: (Describe how quickly the new species may have formed based on the fossil record) Gradualism – small changes occur constantly, until a new species is formed

Timeframes for Evolution 2. Punctuated Equilibrium – a long period of no change is followed by a period of very rapid change, leading to a new species

4.2 - Disease Agents and Natural Selection Page 85

Disease Agents and Natural Selection Disease can act as a selecting force where the organism with the best adapted phenotype survives. A) Pathogen: a disease-causing organism Examples: Virus, Bacteria, Protists (algae & protozoa), and Fungi (yeast) Pathogens trigger an Immune Response The immune system produces antibodies (proteins that tag diseases)

Two Types of Immunity (antibodies that prevent diseases) Passive Immunity: Antibodies are passed from mother to child through the placenta and breast milk Anti-venom are injected serums that contain antibodies Active Immunity: Immune system actively produces antibodies and remembers the foreign invaders Vaccines – weakened or dead virus is injected and triggers production of antibodies

B. AIDS and Natural Selection AIDS (Acquired Immune Deficiency Syndrome) is contracted through HIV (Human Immunodeficiency Virus) LIPID COAT Virus: Non-living, smaller than bacteria; needs to invade cells in order to survive Structure: Capsid (outer protein coat) and DNA or RNA Attacks the T-cells (first antibodies produced) RNA INNER CAPSID OUTER CAPSID

AIDS and Natural Selection 10% of European population is immune to HIV Life-saving random mutation (CCR5-delta 32 mutation)selected for by the devastating black plague epidemics that swept over Europe beginning in the 14th century People who inherit 2 copies of this same mutation are immune to HIV Dominant Gene HIV will recognize And invade cells Mutation HIV will NOT recognize and cannot infect cells

Antiviral Interferes Assembly Antiviral Blocks Antiviral Interferes Replication

AIDS and Natural Selection Antivirals are used to treat AIDS and other viruses Function of Antivirals Block the introduction of viral DNA/RNA into the cell Interfere with the viral genetic material being spliced into host DNA Interfere with assembly of the new viruses

AIDS and Natural Selection Viruses mutate at a blinding pace causing the antiviral drugs to be ineffective. Viruses like HIV will RANDOMLY MUTATE. Sometimes those mutations help the virus evade the drug, reproduce and pass on their genes, making the viral population resistant to the drugs. This is why HIV patients are on the AIDS “Cocktail” Typically 3 different antivirals to compensate for the quick mutation

Evolution Today Antibiotic Resistant Bacteria: Bacteria can be killed with drugs called antibiotics that target parts like cell walls. The overuse of antibiotics is a selection force, constantly leaving behind resistant bacteria that reproduce. MRSA (Methicillin Resistant Staphylococcus aureus)

Evolution Today Pesticide Resistant Insects: RESISTANCE – describes how well the organism can survive exposure to a chemical. If an insect is resistant to pesticide, the pesticide does NOT kill the insect.

Co-evolution/ Antibiotic Resistance http://www.nsf.gov/news/special_reports/science_nation/leafcutterants.jsp http://www.youtube.com/watch?v=R5piJCyHwtw

4.3 A- Classification and Speciation Page 89

Classification and Speciation Given the diversity of life, how do we give names to organisms? First Classification System Devised by Aristotle Two basic groups: plant and animal.

Modern Classification System Devised by Carl Linnaeus (1707-1778) Created a system called Binomial Nomenclature Every organism receives two names Genus and Species The genus specie name is written in a specific format Italicize = Homo sapiens Underline = Homo sapiens Homo is the genus, sapiens is the species

Biological Taxonomy TAXONOMY is the study of classification DOMAIN is the highest taxonomic rank of organisms Domain system consists of three domains: Archae Bacteria Eukarya

King Philip Came Over For Green Soup Taxonomy Seven levels of TAXA were created Kingdom Most General (only 6 Kingdoms) Phylum Class Order Family Genus Species Most Specific (~2 million identified) King Philip Came Over For Green Soup

Taxonomy Specie is the most specific of these seven taxa, thus the specie would contain only one type of organism. Specie is defined as a group of organisms which can interbreed and produce fertile offspring.

Summary Look up the classification for humans Kingdom- ? Phylum- ? Order- ? Family- ? Genus- ? Specie- ?

4.3 B Page 91

Basis for Classification Linnaeus Classification Morphology: Shared physical characteristics Example: Animals – Type of Heart (2 chambers vs 4 chambers) and Blood, live birth vs egg, antennae, wings, etc. Example: Plants – Number of Stamens (male parts), number of styles (female parts)

Modern Classification Biochemical analysis: gram staining bacteria, or comparing DNA and amino acid sequences Embryology: common fetal development

Modern Classification Phylogeny: describes the evolutionary relationships between organisms. Example: Homologous/Analogous structures used to determine relationships

Modern Classification Phylogenetic Trees are used to show a visual representation of the evolutionary relationships Phylogenetic Tree - each node represents the inferred most recent common ancestor, and the edge lengths may be interpreted as time estimates.

Type of Phylogenetic Tree Cladogram – specific type of phylogenetic tree which emphasize the order in which derived characteristics arise from a phylogenetic tree

Tools used in Classification Phylogenetic Tree/Cladogram Dichotomous Key Uses paired statements and visible characteristics to “key out” an organism and identify it.

Sample Dichotomous Key 1. a. Wings covered by an exoskeleton ……………………………….. go to 2 b. Wings not covered by an exoskeleton …………………………… go to 3 2. a. Body has a round shape ……………………………….……….. Ladybug b. Body has a elongated shape ………………….................. Grasshopper 3. a. Wings point out from the side ……………………………......... Dragonfly b. Wings point to posterior of the body ……………….………….. House fly

Summary

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