Wednesday May 4 th Big Idea: Inheritance, Variation, and Adaptation Daily target: I can examine traits and describe how they are homologous or analogous Homework: Fossils Worksheet (5/6) Exam Review (Extra Credit) (5/3) Relative dating Lab (5/4) Vocabulary: Homologous structures: Traits inherited by two different organisms from a common ancestor that have the same structures, but different functions Analogous structures: Body part in different species that is similar in function but not in structure that evolved in response to a similar environmental challenge Vestigial structures: Is an anatomical feature that no longer seems to have a purpose in the current form of an organism of the given species. Entry Task : Why are Index fossils so important to geologist and archeologist? Conclusion: Are a robin’s wing and a butterfly wing homologous or analogous? Plan for Today: Homologous structure notes Homologous structures video MS-LS4-1 Analyze and interpret data for patterns in the fossil record that document the existence, diversity, extinction, and change in life forms through out history of life on earth under the assumption that natural laws operate toady as in the past.

Four Main Types of Evidence 1. Fossils 2. Homologous structures 3.Similar embryo development 4.Geographical distribution

Fossil Record Fossils are evolutionary evidence Fossils show that ancient species share similarities with species that now live on Earth. Fossils records provide evidence that living things have changed over time. GlyptodontArmadillo

Fossil layers show change over time.

Comparing Anatomy Homologous structures Analogous structures Vestigial structures

Homologous structures Anatomically similar structures inherited from a common ancestor These structures can be similar in arrangement but different in function.

Analogous Structures Structures that do not have a common evolutionary origin but are similar in function. Shows that functionally similar features can evolve independently of each other Ex: wing of an insect and wing of bird

Analogous Structures

Vestigial Structures Video Video A body structure that has no function in a present-day organism but was probably useful to an ancestor. This shows a change over time

Evolution Chapter 15

Comparing Embryos Embryo: the earliest stage of growth and development of both plants and animals Vertebrate embryos exhibit homologous structures during certain phases of development but become totally different structures in the adult forms.

Comparing Embryos Similar embryo development may suggest a common ancestor

Biochemical Evidence Common ancestry can be seen in the complex metabolic molecules that many different organisms share. Comparison of the DNA or RNA of different species produce biochemical evidence for evolution

Biochemical Evidence Comparisons of the similarities in amino acids and other molecules across species reflect evolutionary patterns seen in comparative anatomy and in the fossil record.

Geological Distribution Similar animals are found in different locations around the world. Animals ended up evolving similar features for their environment because of their location on earth They look the same but live in different areas

Knowledge Check True or False Organisms with similar anatomy share similar DNA sequences.

A. analogous structures B. embryological structures C. homologous structures D. vestigial structures Which features are similar in use and evolve in similar environments, but do not evolve from a common ancestor? Knowledge Check

Which of the following best explains how the fossil record provides evidence that evolution has occurred? AIt indicates the exact cause of structural and behavioral adaptations of organisms. BIt shows that the form and structure of groups of organisms have changed over time. CIt shows how the embryos of many different vertebrate species are very similar. DIt indicates that forms of life existed on Earth at least 3.5 billion years ago.

Knowledge Check The occurrence of the same blood protein in a group of species provides evidence that these species a. evolved in the same habitat. b. evolved in different habitats. c. descended from a common ancestor. d. descended from different ancestors.

Knowledge Check Which is an example of a derived trait? A. a tail B. bones C. feathers D. teeth