Evolution

Biology Evolution Unit Day 5 ClipBird Lab Biology Evolution Unit Day 5

ClipLand Scene Here we see a new species called ClipBirds. They were tragically split into two populations---the East ClipLand and the West ClipLand. How are these birds alike? How are they different? tell the class a fanciful but engaging story about a population of imaginary birds (Clipbirds) that lives happily in a faraway fictional place, known as Clipland. Point out to the class that somehow the large population became divided into two smaller populations, east and west. Perhaps a mountain range rose up in a big hurry, or a flock of the Clipbirds got lost and ended up on the opposite side of a preexisting range of mountains. (This is fictional, so have some fun with it.) http://www.ucmp.berkeley.edu/education/lessons/clipbirds/scene.pdf

Food Values Food Values in Megacalories Megacalories Needed Marblefruit 10 Big Tootfruit 5 Tiny tootfruit 2 To Survive To Reproduce Big bill 80 160 Medium bill 50 100 Small Bill 25

ClipBird Populations West Clipland East Clipland 1st Season 2nd Season 3rd Season 4th Season Big Bill Medium Bill Small Bill 1st Season 2nd Season 3rd Season 4th Season Big Bill Medium Bill Small Bill

Discussion What happened to these populations? What factors had an impact on their lifestyles?

Vocabulary Adaptation- inherited trait that increases a population’s chances of survival and reproduction in a particular environment. What types of adaptations did we see here?

Vocabulary Niche- habitat and the role a population plays in that habitat. Includes where organisms live, what and how they eat, how they raise their offspring, and what their predators are. What were the examples of the niche that we saw in this lab?

News Reporters You are a news reporter and are writing a story on Charles Darwin and his theory. Need to answer the 6 questions of Who, What, When, Where, Why, and How. Have today during class to find your information. Hand in by tomorrow.

Background Information In Mediaeval times, people believed in Spontaneous Generation. Idea that living things could come from non-living things.

Example of Spontaneous Generation Observation: Every year in the spring, the Nile River flooded areas of Egypt along the river, leaving behind nutrient-rich mud that enabled the people to grow that year’s crop of food. However, along with the muddy soil, large numbers of frogs appeared that weren’t around in drier times. Conclusion: It was perfectly obvious to people back then that muddy soil gave rise to the frogs.

Redi’s Experiment In 1668, Francesco Redi, an Italian physician, did an experiment with flies and wide-mouth jars containing meat. One jar was covered with a stopper, one was covered with gauze, and one was left open.

Redi’s Data In the uncovered jars, flies entered and laid eggs on the meat. Maggots hatched from these eggs and grew into more adult flies. Adult flies laid eggs on the gauze on the gauze-covered jars. These eggs or the maggots from them dropped through the gauze onto the meat. In the sealed jars, no flies, maggots, nor eggs could enter, thus none were seen in those jars. Maggots arose only where flies were able to lay eggs.

Redi’s Conclusions Only flies can make more flies This experiment disproved the idea of spontaneous generation for larger organisms.

Louis Pasteur In1864 Louis Pasteur, disproved spontaneous generation in microscopic organisms. Pasteur boiled broth in various-shaped flasks to sterilize it, then let it cool. As the broth and air in the containers cooled, fresh room air was drawn into the containers. None of the flasks were sealed — all were exposed to the outside air in one way or another.

Louis Pasteur’s Findings Broth in flasks with necks opening straight up spoiled while broth in swan-neck flasks did not, even though fresh air could get it. Broth in flasks with cotton plugs did not spoil, even though air could get through the cotton. If the neck of a swan-neck flask was broken off short, allowing bacteria to enter, then the broth became contaminated.

Who is Jean-Baptiste Lamarck? 1809- French Scientist who reasoned that fossils of extinct animals were the ancestors of those living today. Developed a theory of evolution Organisms are constantly striving to improve themselves. Use it or lose it! Most-used body structures are maintained, while others waste away. Inheritance of acquired characteristics.

Discussion—So What Are the Important Aspects of Darwin’s Theory? Natural Selection Sexual reproduction causes variation within a species, some of which are favorable. There is a struggle for exsistance. Not all young produced in each generation can survive. (Nature overproduces) Individuals that survive and reproduce are those with favorable variations. So here’s the deal. For main concepts of natural selection

Discussion—So What Are the Important Aspects of Darwin’s Theory? Geological Change is slow. These gradual geological changes can influence plant and animal life over time. This Theory is called Gradualism Artificial Selection Selective breeding of domestic animals and crops to gain most desirable characteristics. How does this affect us now?

Vocabulary to Know Terms People and Theories Natural Selction Variation Gradulism Artificial Selection Spontaneous Generation People and Theories Darwin Jean-Baptiste Lamark Louis Pasteur Francesco Redi Add all of these terms and people to your evolution foldables!!

Lucy Activity Where did humans come from? Who are we related to? Lucy, ancient hominid fossil, helps us to bridge the gap in human evolution.

Primate Family Tree Anthropoids Hominoids Hominids Old World African Old World Monkeys Gibbon Orangutans Human Apes Monkeys Anthropoids Hominoids Hominids

Lucy Let’s find out more about Lucy by reading Digging up the Past

Lucy Discussion Comparing hominids from Lucy’s lifetime to your own, do you think there have been more changes in physical characteristics of the body (such as hands, feet, head, posture) or more changes in how hominids lived (types of shelter, ways of getting around, ways of gathering food)? Did Lucy use her structures the same way that we use our own structures today?

Lucy Discussion Which aspects of your description were based on evidence? Which aspects of your description were inferences related to evidence? Which aspects of your descriptions were guesses?

Evidence for Evolution Evolution of Humans Wrong—There is no direct lineage!! Explain how this picture is wrong---Comprehension

So is this correct??? W No, there is no direct lineage!!

So what is right?? We have a common ancestry! Anthropoids Hominoids Old World African Old World Monkeys Gibbon Orangutans Human Apes Monkeys Anthropoids Hominoids Hominids Is this correct? Explain how this diagram is correct when the other two were not---Comprehension We have a common ancestry!

How do we know this? Scientists have come up with multiple ways to show evidence for this theory of evolution. Comparative anatomy Comparative physiology Fossils Immunity resistance

Evidence for Evolution: Comparative Anatomy Homologous Structures Structures that have a common origin but not necessarily a common function. How is the dolphin fin and human arm alike? How are they different?

Evidence for Evolution: Comparative Anatomy Vestigial Structures Structure in an organism that seem to have little to no obvious purpose. Examples in humans Tail bone Wisdom teeth

Evidence for Evolution: Comparative Anatomy Analogous Structures Structures are similar in appearance and function but are different in anatomical development and origin. How is the bat wing and a butterfly alike? How are they different?

Evidence for Evolution: Comparative Physiology DNA Comparison 95 of our DNA genome matches the DNA genome of chimpanzees Enzyme Comparison

Evidence for Evolution: Fossils Fossil Record More simple organisms appeared first Carbon Dating Uses the decay of carbon over time to tell how long the fossils have been in the ground. allows us to organize once living things by age and type. Indicates a change through time

Evidence for Evolution: Resistance Insects have become resistant to different types of farm chemicals Bacteria has become resistant to different types of antibiotics Natural Selection selects towards mutations that are resistant.

Evidence for Evolution: OOPS! Comparative Embryology Similarities in development = genetic similarities This is no longer believed to be true!!

Population Genetics Speciation Evolution of one or more species from a common ancestor -- New species created Species is a group of similar-looking organisms that can breed with one another and produce fertile offspring

Population Genetics Divergent Evolution (Allopatric Speciation) Geological barrier separates members of the population Two different species evolve

Population Genetics Convergent Evolution Natural selection produces analogical adaptations in response to environmental conditions. Two similar species

Population Genetics Coevolution Environmental factors cause two species to evolve together. Special relationships between organisms. Ex. Flowers and bees.

Population Genetics Adaptive Radiation An open habitat creates many different evolutionary tracts for one species Many diverse species from one common ancestor.

So…How Does This Really Happen? Evolution in Genetic Terms: The change in allele frequencies over time.

Population Genetics Mutations: change in genetic information of a cell

Population Genetics Gene Pool: Combined genetic material of all the members of a given population. Allele Frequencies: Percentage of appearance of a single allele in a gene pool. What is the Allele Frequency of blue eyes in this class?

So How Do Adaptations Happen? Natural selection allows an individual with desirable traits to live and pass on the genetic information. Person with correct DNA will pass off their genes to next generation

Population Genetics Genetic Equilibrium: If the allele frequency is constant the allele has reached equilibrium. It will not change unless something big happens to the population.

Population Genetics Genetic Drift: random change in allele frequency in a population due to chance events.