Biology: Feb 28, 2013 Bell Ringer: What is the overall goal of all organisms? Write this on the top of your notes sheet! Objectives: Notes on the History of Evolution Assignment: Lamarck vs. Darwin Interpreting Graphics Study for Vocab Quiz VOCAB QUIZ TOMORROW *Starred Words* Grab the notes sheet from side lab table and get out your vocab words!! EVOLUTION CHANGE OVER TIME What is a theory? A) Just an educated guess B) A tentative answer to a specific question C) An explanation supported by evidence that tries to make sense of many observations made in nature D) Someone’s opinion BIOLOGICAL EVOLUTION A PROCESS TYPICALLY SPREAD OVER MANY GENERATIONS THAT RESULTS IN HERITABLE CHANGES IN A POPULATION. Heritable = Able to be inherited What is the purpose of evolution theory? A) To explain how life first began on Earth B) To explain how the universe was created C) To explain the diversity of life found on earth and the similarities seen between organisms D) To create confusion and controversy PURPOSE OF EVOLUTION THEORY It scientifically explains the diversity of life found on earth and the similarities seen between organisms • During the 1800’s Darwin discovered that the diversity of living species was far greater than anyone had previously known!! • These observations led him to develop the theory of evolution through natural selection!! THE HISTORY OF EVOLUTION THEORY Who first came up with the idea of evolution? A) The Ancient Greeks B) Medieval Scientists C) Charles Darwin D) Satoshi Tajiri (creator of Pokemon) Who first came up with the idea of evolution? The Ancient Greeks!! But they weren’t alone. The concept that species change over time also has roots in the ideas of the Chinese the Romans and in medieval Islamic science. and animal the plant, first animals lived Environmental species were born out life are not perfect inFactors water and animals that... to life forms have an And the struggle ofbut the created Earth, formed by theof in a state live on land were generated innate ability or power Survive Causes the chance combination ofto from them. transform andOfadapt to transformation species potentiality elements. their surroundings over time. including humans! 300 BC Chuang Tzu Augustine Titus Lucretius of Hippo Carus (354-430 (99-55 AD) B.C.) Othman Amr al-Jahiz 815 AD Anaximander (600 BC) http://upload.wikimedia.org/wikipedia/commons/3/38/Anaximander.jpg Meanwhile…. in the Western World • Organisms appeared on earth at the same time. • Organisms were fixed and did not change. • The earth was less than 10,000 years old and changed very little over time • These ideas were widely accepted by scientists and nonscientists for a very long time. Until……….. LINNAEUS • He grouped organisms together according to similar features. • This caused many scientists Why do these guys look alike? to wonder….. 1700’S LINNAEUS • Scientists noticed similarities between animals and began to look for relationships between them. • These observations led to questions that could not be satisfactorily answered by the creation idea How are these 2 species the same? How are they different? As scientists began to notice these things, they began to ask questions. Eurasian Tree Sparrow •Is there a relationship there? •Do they share a common European ancestor? House Sparrow EXAMPLE QUESTIONS • WHY DO SOME SNAKES HAVE THE RUDIMENTS OF TINY LEGS? • WHY DO MANATEES HAVE FINGERNAILS? • WHY DOES A WHALE HAVE FINGERBONES? • WHY DO CAVEFISH HAVE REMNANTS OF EYES? • WHY ARE SOME GROUPS OF SIMILAR SPECIES FOUND ONLY IN CERTAIN PLACES ON EARTH? Ex. 23 species of Honeycreepers found only on the Hawaiian islands. Think, Pair, Share • What is a theory? • What did Linnaeus observe? • LATE 1700’S • First To Publish A Theory Of Biological Evolution • Said Evolution Was A Process Of Adaptation Through the LAMARCK “Inheritance Of Acquired Traits” (organisms acquired traits they needed to survive and then passed these traits on to their offspring) Lamarck: Theory of acquired characteristics Lamarck said organisms acquired traits by using their bodies in new ways These new characteristics were passed to offspring Lamarck was totally wrong! Ex.—He believed that if you cropped a dog’s tail that all of its offspring would be born with cropped tails,…why is this not true? So Lamarck is out…….. 1859 And Darwin is in FOR PROPOSING A THEORY FOR EVOLUTION THAT IS WIDELY ACCEPTED BY THE SCIENTIFIC COMMUNITY TODAY – THE THEORY OF EVOLUTION BY NATURAL SELECTION • 1859 • PROPOSED A THEORY FOR EVOLUTION THAT IS WIDELY ACCEPTED BY THE SCIENTIFIC COMMUNITY TODAY – THE THEORY OF EVOLUTION BY NATURAL SELECTION DARWIN ALFRED RUSSEL WALLACE • 1850’S • TRAVELING NATURALIST • IN 1858,CAME TO THE SAME CONCLUSIONS AS DARWIN. • HIS WORK PROMPTED A RELUCTANT DARWIN TO FINALLY PUBLISH HIS THEORY. T,P,S What did Lamarck propose? Why was he wrong? What did Darwin propose as a theory of evolution? What caused Darwin to publish his information? Assignment Interpreting Graphics You are going to look at the pictures and read the information about Lamarck and Darwin. Then you are going to answer some questions that go with the figures. STUDY FOR VOCAB!! Bell Ringer! Am I going to evolve during my lifetime? Can I grow taller because I stretch to reach my top shelf everyday? Which scientist thought you can acquire traits during your lifetime? Biology Mar 5, 2013 Bell Ringer: Grab Notes Sheet, then… Please get out your reading assignment. Objectives: Quiz Tomorrow: Reading and Lamarck vs Darwin! Go over homework Natural Selection Notes HW: Letter to Lamarck and Study for Quiz! •How Does it Happen? • NATURAL SELECTION • MUTATION • MIGRATION (GENE FLOW) • GENETIC DRIFT • SEXUAL SELECTION • Theory proposed by Darwin in 1859 to explain how evolution could happen • Based on 5 years of observations made during a trip around S. Amer. • (1831 - 1836) • AND over 20 years of study in England (1836 – 1859) Darwin’s Voyage on the Beagle During his 5 years on the HMS BEAGLE : 1. He saw a great diversity of life. 2. He saw similarities between species (especially between mainland species and island species). Marine Iguana Land Iguana Fllightless Cormorant Double Crested Cormorant He also saw similar yet different species from island to island Each island had its own type of tortoises and birds that were clearly different from other islands Galapagos Turtles 3. In Chile Darwin observed the results of an earthquake: the land had been lifted by several feet. 4. In the Andes he observed fossil shells of marine organisms in rock beds at about 4,300 m. He came to agree with Lyell (a young geologist) that over millions of years of earthquakes and other geologic processes could change the geology of the land forming new habitats. . 5. In Argentina, Darwin collected fossils of gigantic armor-plated beasts, megatheres, which were unlike anything else anywhere in the world – nearly. Only the tank-like armadillos, which Darwin had also seen in South America, bore any resemblance to them. Considering these extinct and living forms together, Darwin theorized that megatheres and armadillos might be related. Okay – so the things he saw on the 5 year trip around South America greatly influenced Darwin’s thinking. What else influenced him? BREEDING PROGRAMS OF FARMERS/BREEDERS - He saw how farmers were able to create a wide variety of types of plants and animals through selective breeding programs (artificial selection). Artificial Selection nature provides variation, humans select variations that are useful. Example - a farmer breeds only his best livestock The 5 year trip around South America and the farmers/breeders of England greatly influenced Darwin’s thinking. What else influenced him? LYELL – A geologist who said the earth changed greatly over very long periods of time. This meant the earth must be extremely old. Darwin read his book and saw volcanoes and earthquakes while on the Beagle. Darwin realized that a changing Earth meant changing habitats. Living things/Life had to be able to change (adapt) too. LYELL • 1820-1870’S • GEOLOGIST WHO STATED THAT THE EARTH CHANGES OVER TIME DUE TO EROSION, SEDIMENT DEPOSIT, VOLCANIC ACTION, EARTHQUAKE, ETC. • PROPOSED AN OLDER EARTH BASED ON THESE GEOLOGIC PROCESSES Did anything else influence him? Why yes… THOMAS MALTHUS • Said that the human population increases much faster than food can be produced. This over population leads to famine, wars, disease. These things in turn reduce the population and keep it under control. • Darwin thought this idea of population controls could apply to all species, not just humans. Quick Review: What is the purpose of evolution theory? To explain the observations that not only is there a great diversity in living things, but also the similarities seen between organisms. Quick Review: What did Charles Darwin do? Proposed a theory to explain how evolution happens. It is called the theory of Natural Selection. Quick Review: What influenced Darwin? All the things he observed on the 5 year voyage of the Beagle (animals, plants, fossils, earthquakes) The farmers and animal breeders of England (can create a wide variety with in a small group) The geologist Lyell – the Earth is very old & Is constantly changing. The essay on population controls by Malthus Biology 3/6/13 Bell Ringer: Study for Quiz! Objectives: Quiz Survival of the Sneakiest Natural Selection Notes Natural Selection Quiz Friday Extra Credit Due Friday! • When finished with Quiz pick up the cartoon Survival of the Sneakiest and Read it!! After returning from his trip, Darwin spent the next 20 years researching and gathering evidence for what would become a very earth shaking theory: DARWIN’S THEORY OF NATURAL SELECTION Natural Selection The traits that help an organism survive in a particular environment are “selected” in natural selection Natural Selection and Species Fitness Overtime, natural selection results in changes in the inherited characteristics of a population. These changes increase a species fitness (survival rate) Fitness- the ability of an individual to survive and reproduce in its specific environment brown bigger white smaller fast slow *Who has a higher level of fitness? (who will survive better?) *Who will make babies? + High fitness = lots of babies! Darwin’s theory connects many observations in nature. They are… 1. All species tend to produce excessive #’s of offspring. 2. Resources (food, water, shelter) are limited. . 3. There is a struggle for existence due to over population and limited resources in which only a small % will survive. 4. Individual variation is wide spread in all species. 5. Much of this variation is heritable (in the genes). DARWIN’S THEORY OF NATURAL SELECTION: “SURVIVAL OF THE FITTEST” • Individuals that have advantageous traits (better fitted to their environment) are more likely to survive and reproduce than less “fit” individuals. They will leave the most offspring. • Nature selects the individuals that will reproduce. NATURAL SELECTION • Each new generation will have more individuals with the advantageous traits. This is how a population evolves. • If 2 populations of the same species become isolated from each other, natural selection could cause them to become 2 separate species as they adapt to their different environments. This is how new species evolve. Descent with Modification Each living species has descended with changes from other species over time Summary of Darwin’s Theory 1. Organisms differ; variation is inherited 2. Organisms produce more offspring than survive 3. Organisms compete for resources 4. Organisms with advantages survive to pass those advantages to their children 5. Species alive today are descended with modifications from common ancestors Darwin finally published his ideas in 1859 Other naturalists were developing the same theory that Darwin did. Even though he was afraid of the Church’s reaction to his book he wanted to get credit for his work. Assignment: Finish Reading Survival of the Sneakiest! Answer these questions on Sheet of paper… (I will put them on website) 1. When it comes to crickets, what does fitness mean? 2. Is calling good or bad for a cricket’s fitness? 3. Give some examples of selection at work in this cricket story. 4. How does selection favor calling? How does selection favor not calling? Remember that the Extra Credit is due FRIDAY!!!! Biology March 18 Bellringer: Think about what you know about mutations. How do you think mutations can be harmful and how can they be helpful. Come up with one example of each. Be ready to discuss! Objectives: Notes on Mutations/Adaptations Build-A-Beast Part 1 Grab notes sheet! Principles of Natural Selection 1. Organisms produce more young than can survive 2. Some variations are found between individuals of a species 3. Some variations allow some members to survive and reproduce better than others 4. Over time, offspring with helpful variations will make up more of the population (because of #3) Variation • The appearance of an inherited trait that makes an individual different from other members of the same species (if enough variations occur in a population, a new species may result) Adaptations - Inherited characteristic that increases an organism’s chance of survival • Physical,chemical, behavioral makeup of individual • Better suited to survive means more likely to breed Horseshoe crabs migrate out of water, & move above the tide line to lay their eggs. How does this ADAPTATION allow it to survive? How Do Adaptations Occur? • Mutations • Movement of individuals into or out of a population also changes gene pool • Isolation of some individuals by geography & changes climate MUTATIONS • PROVIDE THE RAW MATERIAL FOR NATURAL SELECTION • THIS IS HOW NEW TRAITS ARE ADDED TO A POPULATION. Mutations randomly occur in the genes of species 1.)good mutation= survive, pass on gene ex: longer legs on a deer-faster 2.) bad mutation= get killed ex: albino in a forest Real World Example! Sticklebacks Camel adaptations- Desert Long eyelashes to keep sand out of eyes Large hoofs to keep from sinking into sand Thick eyebrows to shield eyes from desert sun Can drink 32 gallons of water at one session Store fat in camel hump-go months w/o eating Thick lips to chew through cacti w/o pain Hair in and around ears to prevent sand from entering Brown in color to blend in with surroundings Giraffe adaptations-African grassland Long necks to eat from tall trees and spot predators Can drink 12 gallons of water in one sitting Spotted so they can blend in with tree leaves Large heart to pump blood all the way up their neck and into brain, 3 X stronger than human heart Long tough tongue to bite through prickly leaves, also used to hold onto branches, can be 18in long BUILD A BEAST! This activity is about creating animals with useful adaptations. The animal's environment is given, because that is how Darwin's theory of evolution and adaptation work: the individual organisms that are best adapted to their particular environments survive, so the adaptations gradually appear in more and more of the population. Different adaptations are helpful for different environments: For a rabbit living in the Arctic, white fur would be helpful to avoid being seen by predators. For a rabbit living in the woods, being white would make it more conspicuous, but being brown would be helpful *Roll 1 dice 5 times and record your numbers in order! Ex: 4,4,5,1,2 • A) WHERE DOES IT LIVE? 1 - mountains 2 - flatlands 3 - rocky, harsh 4 - small island 5 - near a volcano 6 - in a cave • B) HOW MUCH WATER IS THERE? 1 - almost none; dry and barren 2 - water part of the year, drought the rest 3 - lots of precipitation all year 4 - near a coastline 5 - in a swamp 6 - in the ocean • C) WHAT IS THE CLIMATE/WEATHER LIKE? 1 - hot and humid 2 - hot and dry 3 - moderate 4 - cold, rainy, and windy 5 - seasons change from hot to cold 6 - sub-zero temperatures • D) WHAT DOES IT EAT? 1 - leaves from tall plants 2 - fungus growing under rocks 3 - berries, plants, and small animals 4 - water animals 5 - swift running deer-like animals 6 - flying insects • E) WHAT EATS IT? 1 - stompsuckers squash it flat 2 - vampire butterflies land on it and suck it dry 3 - buzzbugs lay eggs that burrow into its skin 4 - web devils set gooey traps to catch it 5 - ratrax packs are wolf-like and chase it 6 - megaworms leap out of the sand and swallow it Use this information to come up with at least 8 adaptations! (If you add more, they can be worth extra credit) Please list your 8 adaptations. Be creative, and explain why your beast has/needs each adaptation. I will show you an example… 1. Lives on a small island 2. Near a coastline 3. Seasons change from hot to cold 4. Eats leaves from tall plants 5. Predators are vampire butterflies that land on it and suck its blood Adaptations: 1. Green/blue in color to blend in with water and leaves 2. Long tongue to reach high leaves and pull them off 3. Large feet so he doesn’t sink into the sand 4. Long legs that are retractable when swimming but useful for reaching up tall trees 5. Hard shell back so vampire butterflies can’t bite him 6. Long tail with spines to swat away vampire butterflies 7. Wings that work to fly and help when swimming 8. Long neck to allow for reaching into tall trees 9. Ability to store fat under shell and hibernate if necessary during winter months Biology: March 19, 2013 Objectives: Build-A-Beast Part 2 Assignment: Read Section 14-4 and fill in reading guide! Quiz Friday! Grab a piece of white paper from side table! Use the adaptations you created to draw your beast 1. Include at least 8 adaptations (if you add more they will be extra credit) 2. Label the adaptations and how they are helpful 3. Should be colored or shaded—add in your habitat! *Make sure you give your beast a name! You will turn these in at the end of the hour!! Homework: (When you finish your beast) Read Chapter 14-4 (pages 310-316) Fill out the reading guide as you read! (reading guide on back lab table) Biology March 20, 2013 Bellringer: --Grab the notes sheet… THEN Look at your list of adaptations from Build-A-Beast. Identify one of each that you used: ChemicalPhysicalBehavioralObjectives: Population Evolution Notes QUIZ FRIDAY!!! HW: Analyze populations… Over… Notes Monday, reading last night, Notes Today! TEST TUESDAY!!! You will get a review sheet tomorrow! Put your homework out on your desk.. I am going to check it! Population •A group of individuals of the same species living in the same area. Species •Group of similar organisms that can breed and produce fertile offspring Speciation •Process by which a new species is formed •How does Speciation occur? Gene Pool •The combined genetic information of all of the members of a population GENETIC DRIFT • PROCESS IN WHICH GENE FREQUENCIES WITHIN A POPULATION CAN CHANGE BY CHANCE – NATURAL SELECTION NOT INVOLVED. CHANCE OCCURRANCES INCLUDE : - 1 INDIVIDUAL PRODUCES MORE OFFSPRING THAN OTHERS JUST BY CHANCE - PART OF A POPULATION IS DESTROYED IN A DISASTER (EARTHQUAKE, FLOOD, ETC) - EXAMPLE - NORTHERN ELEPHANT SEAL 1890 POPULATON < 20 DUE TO HUNTING. THE SURVIVORS WERE JUST THE LUCKY ONES. The Bottleneck Effect • Population bottlenecks occur when a population’s size is reduced for at least one generation. • Can reduce genetic variation very quickly, even if only for one generation! Founder’s Effect • A founder effect occurs when a new colony is started by a few members of the original population. • This small population size means that the colony may have: – reduced genetic variation from the original population. – a non-random sample of the genes in the original population. GENE FLOW Migration • THE EXCHANGE OF GENES BETWEEN 2 OR MORE POPULATIONS • THE GREATER THE GENE FLOW, THE LESSER THE GENETIC DIFFERENCES BETWEEN THE POPULATIONS • THE LESSER THE GENE FLOW, THE GREATER THE DIFFERENCES. Sources of Genetic Variation 1.Mutation 2.Gene Shuffling Mutation •A change in the DNA of an organism Mutation • Might affect the phenotype of the organism • Might affect the organism’s ability to survive and reproduce (fitness) Gene Shuffling •Rearranging of genes during reproduction •Occurs in organisms that reproduce Sexually Gene Shuffling cont. •In humans, gamete formation can result in 8.4 million different gene combinations. •Natural Selection acts on Phenotypes! •Natural Selection determines which genes will be passed on to the next generation •Natural Selection can affect the genotype and phenotype of a population Natural Selection and Phenotype • Natural Selection can affect the distribution of phenotypes in 3 ways: • Directional Selection • Stabilizing Selection • Disruptive Selection Directional Selection • Individuals at one end of curve have an advantage (more fit). • Over time, the curve will move in one direction. Disruptive Selection • Individuals at the upper and lower end of the curve have an advantage (more fit) • Eventually, the curve splits into both directions Stabilizing Selection • Individuals in the middle of the curve have an advantage • The curve stays narrow and in the same place Assignment: Patterns and Mechanisms of Evolution Packet… You will interpret different scenarios and graphs and decide which type of selection is occurring. This is due tomorrow!!!!! (1-11) I WILL BE CHECKING!!! Evidence of Evolution 1.Fossils 2.Biogeography 3.Anatomy/ Embryology 4. Biological Molecules 1.Fossil – preserved remains or evidence of an ancient organism - Fossil record shows transitional organisms & intermediate stages of org’s that are now extinct - Are gaps in fossil record Kinds of Fossils 1. imprint in a rock (leaf, feather, organism) 2. cast made that filled in hollows of an animal track or shell 3. petrified wood or bone (actually replaced w/minerals) 4. frozen in ice,…these are the remains of “Lucy” found in the mountains of Asia 5. Insect or other organism trapped in plant resin (amber) …tar pits *sedimentary rock contains the most fossils because it’s formed by layers of fine particles settling out of a liquid (shale, sandstone, limestone – most of the 3) Fossil Dating 1. Relative Dating – look at layers of rock – the lower the layer, the older the rock 2. Radioactive Dating – uranium & radioactive carbon are used (as radioactive elements change & become more stable, they give off radiation) -Scientists determine age of a rock by comparing amount of stable product w/ amount of radioactive element still present. -Scientists divided Earth’s history into eras and periods to make up the geologic time scale. -When both systems (Relative & Radioactive Dating) are used together, accurate estimates can be made of a fossil’s age. 2) Biogeography • study of the locations of org’s around the world –provides evidence of descent w/ modification: each living species has descended with changes, from other species over time 3) Anatomy/Embryology Homologous structures: different mature structure but develop from same embryological tissues • Many structures of org’s are similar - Ex: bones in the human hand, bat’s wing, whale’s flipper - The # & arrangement of bones in human hand is same as in whale’s flipper & bat’s wing Forelimbs of Vertebrates Vestigial structures: organs reduced in size/function that they are just traces of homologous structures in other species Ex: whale’s vestigial pelvis & skink’s legs • Related species show similarities in embryological development Embryology Embryo = early stages of org’s development • Animals have very similar embryos Chicken Turtle Rat Match the following org’s to the correct embryo: turtle, human, rat, chicken Human Chicken 4) Biological Molecules • Similarity in the subunit sequences of biological molecules (RNA, DNA, and proteins) indicates a common evolutionary history Hemoglobin Comparison WHY IS IT IMPORTANT TO UNDERSTAND EVOLUTION? • BECAUSE BACTERIA ARE BECOMING RESISTANT TO ANTIBIOTICS THROUGH EVOLUTION • BECAUSE DISEASE CARRYING MOSQUITOES ARE BECOMING RESISTANT TO PESTICIDES THROUGH EVOLUTION • WE NEED TO UNDERSTAND HOW THESE CHANGES ARE HAPPENING SO WE KNOW HOW TO FIGHT BACK MODERN EVOLUTION THEORY Molecular Biology Genetics + Evolutionary Biology Has an impact on many different types of Evolutionary Biology scientific studies: Biochemistry Ecology Genetics Physiology Psychology Medicine Philosophy Computer Science