HAPPY THURSDAY Journals out! Bellwork (left side): Quickwrite – in 43 words explain why this would be happening? Two species of mice live in a field in the middle of East Texas. One mouse species is WHITE with BLACK spotting. The other is BROWN with WHITE spotting. After a year, the population of white mice has dramatically decreased, while the population of the brown mice has slightly increased. Turn in Family Tree Projects in the back of the room. Due today for up to a 70. Make sure name, date and period number are clearly written on them.

Due Dates Natural Selection Video guide: Due today Family Tree: today for a 70, tomorrow for a 50 Notecards: due Monday (word, definition, picture)

Journals out, you diploids Journals out, you diploids! Page:_____ Title: Intro to Evolution EQ: How do natural selection and adaptations work to increase diversity within a species?

B.7C - Analyze and evaluate how natural selection produces change in populations, not individuals. B.7E - Analyze and evaluate the relationship of natural selection to adaptation and to the development of diversity in and among species.

What is Evolution?

Evolution: change in the traits of a population over time

Evolution is “the grand unifying theory of biology Evolution is “the grand unifying theory of biology.” Evolutionary theory continues to change as new data are gathered and new ways of thinking arise.

Gene pool: the total number of genes of every individual in an interbreeding population.

Evolution can also be defined as a change in the gene pool over time.

Evolution can also be defined as a change in the gene pool over time.

What important contribution did Charles Darwin make to biology?

Charles Darwin: contributed more to our understanding of evolution than anyone else. Darwin traveled, made observations and collected evidence

Darwin published the results of his work in a Darwin published the results of his work in a book called On the Origin of Species.

Mechanisms of Evolution (How does evolution happen?)

There are 5 factors that can cause evolution to happen and affect the frequency of a gene in the gene pool. Genetic Mutation Non-random mating Natural Selection Small Population Gene Flow

1. Genetic Mutation: DNA errors in replication, transcription, translation, or because of environmental factors. The source of all new genes/traits in a population

If mutations are passed on to offspring (over generations), then evolution has occurred

2. Non-Random Mating Not all mates are created equal. In many species, mates are not selected at random. They are chosen for specific characteristics.. This limits the size of the gene pool because only the genes of the mating individuals are passed to the next generation.

3. Natural selection: individuals with characteristics not well suited to their environment either die or leave few offspring. It is not seen directly, but only observed as changes in a population over a long time.

3. Natural Selection advantageous genes are passed on to the next generation while harmful or unfavorable genes are eliminated from the gene pool survival of the fittest *the driving force of evolution

Examples of natural selection

Why does natural selection happen?

1. Environmental resources: limits the size of populations

2. Fitness: the ability of an organism to survive and reproduce.

3. Adaptation: any inherited characteristic that increases an organism’s chance of survival.

Successful adaptations:. - enable organisms to become better suited to Successful adaptations: - enable organisms to become better suited to their environment - increase an individual’s ability to survive and reproduce. Humans have thousands of adaptations: large brain, opposable thumbs, excellent sensory organs, light, strong skeleton, etc.

Closure: True or False? T T F T T F Natural selection is one of several evolutionary processes Species living today continue to evolve Individual organisms can evolve Evolution can occur rapidly Species can choose to evolve what they need to survive through natural selection Evolution is a process that makes organisms perfectly adapted to their environments T F T T F

Summary of Darwin’s Theory: Individual organisms differ and some of these variations are heritable (passed on) Organisms produce more offspring than can survive and many that do survive do not reproduce Because more organisms are produce than can survive, they must compete for limited resources (food, shelter, etc) Each unique organism has different advantages (good) and disadvantages (bad) Individuals best suited to their environment survive and reproduce successfully These organisms that survive pass their heritable traits to their offspring

Summary of Darwin’s Theory cont’d: Other individuals that are not suited for their environment die or leave few offspring This process called natural selection causes species to change over time Species alive today are descended with modification from ancestral species (their ancestors) This process by which diverse species evolved from a common ancestor unites all organisms on Earth into a single tree of life

Check you grade in the back. What to do: IF YOU HAVE NOTHING TO MAKE UP: Check you grade in the back. Figure out which of the assignments you need to make up. Get the assignment. When finished, turn it in to you class period tray. Congratulations! You won a trip to space! You are going to Mars to study the organisms that live there. When you arrive you observe 2 new species. Using the basic characteristics of Mars, create the two species you encounter with adaptations that are appropriate for life on Mars. Write 5 sentences describing the organisms and draw a picture of them on Mars. Basic Characteristics of Mars: Diverse terrain, including: mountains, valleys, polar ice caps, deserts Atmosphere has clouds, thus rain The red color is due to blowing sand Has vegatation It is VERY cold.