Warm Up #11 – True/False The environmental conditions of Earth have changed since life began and are changing today. Evolution happens when individuals “get used to” a new situation. Individuals can develop new traits because they need them for survival. Except for differences between males and females and young and old, all members of a population look and act the same. Evolution occurs when favorable, inherited traits lead to successful reproduction in some individuals. Species that have no obvious, physical similarities have no similarities at all. Humans share a common ancestor with other species. Humans evolved from other primates such as apes.

Written Response #1 Using the two popularly used memes to disprove or claim that evolution cannot be true…as a group discuss/consider why these ideas may also be false. IN OTHER WORDS SUPPORT HOW EVOLUTION SHOWS THESE IDEAS TO BE WRONG. (Use your reasoning skills. No technology for this activity.)

History of Evolution Scientific theory: a widely supported hypothesis that is based off of repeated experimentation and investigation Not proven Many are widely accepted throughout the scientific community

Abiogenesis The theory that life can come from non-living things Theory of spontaneous generation: up until the 17th century, scientists once thought life came from decaying matter

Written Response #2 Draw the chart to the right into your notebook twice and label one chart Redi…set go…lol. Don’t do that. Label one chart Redi and the other Pasteur. Complete the chart based on the next slide…we will viewing it shortly. Control Group Experimental Group Independent Variable Dependent Variable Observations Results Conclusions

Disproved by 2 people: Francisco Redi Louis Pasteur Experiment to test whether maggots (living) spontaneously generated from meat (non-living) Experiment to test whether bacteria (living) spontaneously generated from beef broth (non-living)

Theory of Biogenesis Redi & Pasteur’s experiments proved theory of biogenesis: All living things come from other living things

History of Evolution Evolution = change over time Gradual process Occurs over many generation Best genes are passed from a parent of offspring May lead to the formation of a new species Species: organisms that can breed and produce fertile offspring

Lamarck Theory of acquired characteristics He said an individual can acquire changes during its lifetime and pass them on to their offspring Example: a body builder with huge muscles would pass on the huge muscles to the baby

Lamarck THIS THEORY WAS WRONG!! Long neck Short neck

History of Evolution Based off of Lamarck’s theory of use and disuse If an organism did not use a particular trait, they could lose it in their lifetime If an organism needed a particular trait, they could acquire it in their lifetime Example: giraffes stretch their necks to reach food FALSE!

History of Evolution Father of evolution: Charles Darwin Voyaged to the Galapagos islands in 1831 Off the coast of South America On the HMS Beagle Observed the flora and fauna of the islands AKA: plants and animals

History of Evolution Some of Darwin’s original thoughts Notice the “I think” written above his sketch of a phylogenic tree His book, On the Origin of Species, sold out on the day it was published in 1850

History of Evolution Finches: similar looking species on the islands, except for their beaks Each type had adapted to their diet Seed eats: thick, rigid beaks Fruit eats: thinner, less rigid beaks Nectar eaters: long, thin beaks

History of Evolution Darwin also observed tortoises, cacti, birds, reptiles Each type of organism had different adaptations that allowed them more reproductive success Darwin developed his theory of natural selection:

Natural Selection https://www.youtube.com/watch?v=vnktXHBvE8s Natural selection explains: the giraffe evolved to have long necks because the successful ancestors passed on the beneficial genes so the species as a whole could change

Theory of Natural Selection as a Process Variation of traits within the population leads to different phenotypes. Some variations are better suited to the current conditions of the environment. Overproduction in population leads to competition for resource (food, shelter, etc.) Natural selection favors the best suited phenotype at the time. This does not mean that the struggling will die, but will be in a poorer condition. The survival of the best adapted (“fittest”) individuals leads to higher success in reproduction and variations will be passed on to the offspring. If the environment does not change over time, favorable variations will become more common.

Central to the theory of natural selection is the idea of adaptations. Adaptation: heritable trait that suits and organism to its natural function in its environment. There are three types of adaptations: Structural adaptations such as defensive structures, mimicry and camouflage. Behavioral adaptations such as herding, schooling and growling. Physiological adaptations such as enzymes, oxygen- binding of hemoglobin and sight.

Written Response #3 Describe what you see in each of the picture frames (1,2, and 3). Describe what happened to the number and color of mice from picture #1 to picture #3. Explain WHY you think the number and color of mice changed from picture #1 to picture #3. Using the terms population, adaptation, natural selection, and fitness justify the change in the number and color of mice over time.

History of Evolution Written Response #4: if natural selection explains the gradual change in a species over time, how did Earth evolve to the point where it is today?

History of Evolution Earth’s History: Earth formed as a large mass filled with water vapor 4.6 billion years ago As the planet cooled, the vapor condensed into rain, providing it with oceans and water bodies Atmospheric conditions: water vapor, methane, hydrogen, ammonia No oxygen! How did we get oxygen?

History of Evolution Theories about the origin of life: Abiogenesis: life from nonliving matter FALSE!! Miller and Urey’s experiment: recreated early conditions using a simulated environment Hydrogen, ammonia , methane and water vapor Lightning: introduced electricity

History of Evolution What happened when electricity was introduced? Caused amino acids to form Amino acids make up vital PROTEINS Protocells (first cells) began to form and evolve Single-celled, anaerobic organisms Produced oxygen through cellular processes (photosynthesis)

History of Evolution 4.6 billion years ago: formation of Earth Precambrian Era (3.5 billion years ago) Evolution of single-celled organisms Production of oxygen Paleozoic Era (540 million years ago) Evolution of invertebrates Then fish, reptiles and conifers evolved Mesozoic Era (245 million years ago) Evolution of flowering plants, dinosaurs and mammals Cenozoic Era (66 million years ago) Evolution of placental mammals and humans

Written Response #5: Answer the questions below in as much detail as possible: Based on what we have discussed up to this point; explain why the first cells on Earth would most likely be prokaryotic cells? (Consider environmental conditions and cell structure when answering this question.) The first cells on earth were prokaryotic because the Earth lacked an oxygen rich atmosphere. Due to prokaryotic cells being anaerobic (no requiring oxygen) and autotrophs (produce their own food). What occurred on Earth that would allow more complex cells and organisms to evolve? Prokaryotic cells produced oxygen through the process of photosynthesis releasing oxygen into the atmosphere Summarize the endosymbiont hypothesis. Larger heterotrophs consumed the smaller cells and harnessed energy from these smaller cells. Smaller cells evolved into mitochondria and chloroplasts and nuclear envelope formed around DNA.