Jean-Baptiste Lamarck a French botanist a French botanist Lamarck’s Theory: Inheritance of Acquired Characteristics Lamarck’s Theory: Inheritance of Acquired Characteristics He believed that acquired traits could be passed down to offspring (inheritance). He believed that acquired traits could be passed down to offspring (inheritance). To get through actions on your part

Theory of Inheritance of Acquired Characteristics Altered behavior leads to greater or lesser use of a given structure or organ, Altered behavior leads to greater or lesser use of a given structure or organ, The use of the structure or organ would cause it to increase in size, whereas disuse would cause it to shrink or disappear. The use of the structure or organ would cause it to increase in size, whereas disuse would cause it to shrink or disappear. The acquired traits would be inherited in the next generation. The acquired traits would be inherited in the next generation. Changes in physical anatomy occur to meet the organism’s needs. Changes in physical anatomy occur to meet the organism’s needs. To receive from an ancestor

Lamarckism Theory: Example The giraffe’s neck: “At some point in the past, giraffes must have found themselves in an environment where they had difficulty reaching food on the tops of trees. The giraffe’s neck: “At some point in the past, giraffes must have found themselves in an environment where they had difficulty reaching food on the tops of trees. In order to eat, they must have had to stretch their necks and in doing so physically, this lengthened their necks. In order to eat, they must have had to stretch their necks and in doing so physically, this lengthened their necks. This longer neck was passed on to the next generation, who in turn stretched their necks even further, thus resulting in the giraffe species having VERY LONG necks. This longer neck was passed on to the next generation, who in turn stretched their necks even further, thus resulting in the giraffe species having VERY LONG necks.

Do you agree with Lamarck?

Charles Darwin ( ) Was influenced by Thomas Malthus’ essay that said that humans in a competitive struggle will fight until only the strong survive. Was influenced by Thomas Malthus’ essay that said that humans in a competitive struggle will fight until only the strong survive. Proposed that all species have evolved over time from one or a few common ancestors through the process of natural selection. Proposed that all species have evolved over time from one or a few common ancestors through the process of natural selection. Evidence was collected on the Galapagos Islands Evidence was collected on the Galapagos Islands Wrote “On the Origin of Species” Wrote “On the Origin of Species” Coined term, “Survival of the fittest” Coined term, “Survival of the fittest” Knew traits were passed generationally but didn’t know how Knew traits were passed generationally but didn’t know how

Darwin’s Theory of Natural Selection Natural selection is the process where organisms who are better suited to their environment survive, reproduce, and pass the “good” genes down to their offspring. Natural selection is the process where organisms who are better suited to their environment survive, reproduce, and pass the “good” genes down to their offspring. Organisms are better suited because of favorable genes the organism inherited from a parent generation. Organisms are better suited because of favorable genes the organism inherited from a parent generation. Darwin observes in nature that members of the same species are born with variations (different phenotypes) in their appearance which are controlled by their genes (genetic make-up). Darwin observes in nature that members of the same species are born with variations (different phenotypes) in their appearance which are controlled by their genes (genetic make-up). If these variations enable the organism to increase their survival then these genes will increase in frequency in the population. If these variations enable the organism to increase their survival then these genes will increase in frequency in the population.

5 principles of Natural Selection (add to notes) PRINCIPLEEXAMPLE Variations exist within populations.Students in a class all look different. Variations are inherited.You look similar to your ancestors. Organisms produce more offspring than can survive. Animals and plants have great reproductive potential, but most offspring are lost to predators, disease or other factors. Relatively few survive to reproduce. Individuals with variations best suited for the habitat survive and reproduce. This is the main idea behind natural selection. The environment is not selecting organisms. Instead, organisms with the “best “ traits survive. A population will change over time.The peppered moth experience.

Darwin’s Theory of Natural Selection Over time these adaptations may result in the emergence of new species (speciation). Over time these adaptations may result in the emergence of new species (speciation). Fitness refers to the physical and behavioral traits that allow an organism to survive and reproduce. Fitness refers to the physical and behavioral traits that allow an organism to survive and reproduce. Favorable(helpful) traits increase an organism's fitness. Favorable(helpful) traits increase an organism's fitness. Mutations sometimes allow organisms to survive changing conditions. Mutations sometimes allow organisms to survive changing conditions. Examples: pesticide and antibiotic resistance Examples: pesticide and antibiotic resistance A change in a gene

Artificial Selection vs. Natural Selection Artificial selection is the intentional reproduction of individuals in a population that have desirable traits. Example: dog breeders Turn and Talk: Are there downsides to artificial selection? There can be a down side to artificial selection. Because this process essentially removes variation in a population, selectively bred organisms can be especially susceptible to diseases or changes in the environment that would not be a problem for a natural population. Inbreeding — the mating of closely related individuals — is also a problem. In dogs, this has resulted in breeds that have health issues ranging from decreased life span to hip dysplasia.

Artificial Selection vs. Natural Selection Artificial selection is the intentional reproduction of individuals in a population that have desirable traits. Example: dog breeders Are there downsides to artificial selection? Turn and Talk: Are there downsides to artificial selection? There can be a down side to artificial selection. Because this process essentially removes variation in a population, selectively bred organisms can be especially susceptible to diseases or changes in the environment that would not be a problem for a natural population. Inbreeding — the mating of closely related individuals — is also a problem. In dogs, this has resulted in breeds that have health issues ranging from decreased life span to hip dysplasia.

Today’s Formative Assessment 1. Create a brief summary of the main differences between the two theories relating to the point below. Use the following table for your summary. 2. Write a paragraph on why we should believe Darwin and disprove Lamarck. Provide examples to support your argument. LamarckDarwin Evolutionary time Role of environment Role of the organism

Pesticide Resistance Pesticides are chemicals that kill insects. Pesticides are chemicals that kill insects. Resistance is an organism’s ability to not be harmed by an agent like an antibiotic. Resistance is an organism’s ability to not be harmed by an agent like an antibiotic. Some insects in a population have variations that enable them to survive the pesticide. They are pesticide-resistant. Some insects in a population have variations that enable them to survive the pesticide. They are pesticide-resistant. The pesticide resistant organisms survive, reproduce and pass the favorable trait to the next generation of offspring. The pesticide resistant organisms survive, reproduce and pass the favorable trait to the next generation of offspring. Generation- one step in the parental line of an organism. Each successive round of offspring makes a new generation. Generation- one step in the parental line of an organism. Each successive round of offspring makes a new generation.

Antibiotic Resistance Bacterial infections are treated with drugs called antibiotics. Bacterial infections are treated with drugs called antibiotics. Some bacteria have traits that make them resistant to an antibiotic. Some bacteria have traits that make them resistant to an antibiotic. Over time, enough of these resistant bacteria survive and reproduce making antibiotics ineffective against the infection. Over time, enough of these resistant bacteria survive and reproduce making antibiotics ineffective against the infection. Tuberculosis(TB), pneumonia and ear infections are diseases that are now hard to treat because of antibiotic-resistance. Tuberculosis(TB), pneumonia and ear infections are diseases that are now hard to treat because of antibiotic-resistance. Overuse and misuse of antibiotics contributes to resistance, as well. Overuse and misuse of antibiotics contributes to resistance, as well.

Check for Understanding Read and Answer the questions on page 170 in the Coach workbook. Read and Answer the questions on page 170 in the Coach workbook.

Evidence of Evolution There are many pieces of evidence that make the theory of evolution more convincing: There are many pieces of evidence that make the theory of evolution more convincing: Fossil records Fossil records Comparative anatomy Comparative anatomy Comparative embryology Comparative embryology Comparative biochemistry Comparative biochemistry Geographic distribution Geographic distribution adaptations adaptations

Fossil Records Fossils are remains or traces of organisms that lived in the past. Fossils and the order in which they appear in layers of sedimentary rock are the strongest evidence of evolution. Fossils show that ancient creatures share similarities with species that now live on earth.

Fossils Records Relative dating is a way to identify the approximate idea of the age of a fossil or rock by comparing it to another fossil. Radioisotope dating (Carbon dating) is a more accurate way to determine age of a fossil. It uses Carbon-14 to compare to the amount of carbon decayed in the fossil.

Comparative Anatomy: Anatomical Structures Morphology- the study of life forms Morphology- the study of life forms The root Morph means “form” The root Morph means “form” Homologous, Vestigial and Analogous structures are all examples of comparative anatomy Homologous, Vestigial and Analogous structures are all examples of comparative anatomy Homologous Structures Homologous Structures Homo=same; Similar structures that originated from a same or common ancestor. Homo=same; Similar structures that originated from a same or common ancestor. Example: forelimbs of the penguin, alligator, bat, and human. Example: forelimbs of the penguin, alligator, bat, and human.

Homologous Structures Same type of bones in each structure originating from a common vertebrate ancestor. However, structures serve different functions.