The Living Environment Unit 4 History of Biologic Diversity Unit 15 Evolution: (15.2) Evidence of Evolution-class key. Name: Class key.

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1 Name: Class key Period:

2 Topic 15.2 assignments Pages/Sections Date Assigned Date Due

3 Topic: Evidence for Evolution Objective: What scientific evidence supports evolution theory? Evidence supporting evolution 1. fossil record shows change over time 2. anatomical record comparing body structures i. _homologous_ & vestigial structures ii. _embryology_ & _development_ 3. _molecular_ record comparing protein & DNA sequences 4. artificial selection human caused evolution

4 Topic: The Fossil Record Objective: Describe the fossil record support for evolution. Layers of rocks contain fossils o new layers cover older ones creates a record over time o fossils show a series of organisms have lived on Earth over a long period of time Fossils: direct or indirect remains of organisms preserved in media such as sedimentary rock, amber, ice, or tar.

5 Topic: The Fossil Record Objective: Describe the fossil record support for evolution. What has the fossil record shown us? o The creatures alive today haven t always been around.

6 Topic: The Fossil Record Objective: Describe the fossil record support for evolution. Evolution from sea to land o 2006 fossil discovery of early tetrapod 4 limbs Missing link from sea to land animals

7 Topic: The Anatomical Record Objective: Describe how anatomy can support evolution. Compare the bones o The same bones under the skin o limbs that perform different functions are built from the same bones

8 Topic: Homologous Structures Objective: Describe how anatomy can support evolution. Structures that come from the same origin o homo- = same ; -logous = information o forelimbs of human, cats, whales, & bats o same structure on the inside o same development in embryo o different functions on the outside o evidence of common ancestor

9 Topic: Analogous Structures Objective: Describe how anatomy can NOT support evolution. But don t be fooled by these o analogous structures o look similar on the outside same function o different structure & development on the inside different origin o no evolutionary relationship o dolphin : aquatic mammal fish : aquatic vertebrate both adapted to life in the sea not closely related

10 Topic: Vestigial Organs Objective: Describe how anatomy can support evolution. vestigial organs o Structure a body structure in a present-day organism that no longer serves its original purpose, but was probably useful to an ancestor. o Hind leg bones on whale fossils

11 Topic: Comparative Embryology Objective: Describe how embryology can support evolution. development of embryo tells an evolutionary story o similar structures during development

12 Topic: Molecular Record Objective: Describe how chemical evidence supports evolution. Molecular ( chemical ) record o Comparing DNA & protein structure o Everyone uses the same genetic code! o Same DNA Huma Macaque Do Bird Frog Lamprey

13 Topic: Branching Ancestry Objective: Describe phylogenic trees and evolutionary theory. Building family tree o Closely related species are branches on the tree coming from a common ancestor

14 Topic: Artificial Selection Objective: Have humans impacted the evolution of organisms? How do we know natural selection can change a population? o we can recreate a similar process o evolution by human selection Selective breeding Unexpected consequences of artificial selection o Insecticide resistance Spray the field, but insecticide didn t kill all individuals variation resistant survivors reproduce resistance is inherited insecticide becomes less & less effective

15 Name: Period: Carefully remove this sheet from your packet to hand in. Work silently and alone to complete this graded exercise. Check for Understanding 1. Describe how the fossil record can support evolution theory. 2. Describe a difference between homologous and analogous structures. 3. In the primate family tree (p.13), when did apes evolve? 4. How does evolution and selective breeding compare?

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17 Topic: Environmental Adaptation Objective: Describe how surviving organisms have adapted. Adaptations: Evidence for Evolution o An adaptation is any variation that aids an organism s chances of survival in its environment. o According to Darwin s theory, adaptations in species develop over many generations o Learning about adaptations in mole-rats can help you understand how natural selection has affected them.

18 Topic: Structural Adaptations Objective: Describe the adaptations of structures over time. structural adaptations arise over time o camouflage, an adaptation that enables species to blend with their surroundings. Because well- camouflaged organisms are not easily found by predators, they survive to reproduce. o mimicry is a structural adaptation that enables one species to resemble another species. Predators may learn quickly to avoid any organism with their general appearance

19 Topic: Structural Adaptations Objective: Describe the adaptations of structures over time. Adaptations can develop rapidly In general, most structural adaptations develop over millions of years. However, there are some adaptations that evolve much more rapidly. The evolution of insecticide resistance is an example of fast natural selection in action.

20 Topic: Convergent Evolution Objective: Describe concept of convergent evolution. Convergent evolution o 3 groups with wings o Does this mean they have a recent common ancestor? Flight evolved 3 separate times evolving similar solutions to similar problems

21 Topic: Natural Selection Objective: Describe how natural selection acts on variations. Natural selection acts on variations There are three different types of natural selection that act on variation: directional, disruptive, and stabilizing.

22 Topic: Natural Selection Objective: Describe stabilization and directional selection. Stabilizing selection is a natural selection that favors average individuals in a population. Directional selection occurs when natural selection favors one of the extreme variations of a trait.

23 Topic: Natural Selection Objective: Describe disruptive selection. In disruptive selection, individuals with either extreme of a trait s variation are selected for.

24 Topic: The Evolution of Species Objective: Describe disruptive selection. Significant changes in the gene pool could lead to the evolution of a new species over time. The evolution of new species, a process called speciation, occurs when members of similar populations no longer interbreed to produce fertile offspring within their natural environment.

25 Topic: Evolution Isolation Objective: Describe isolation processes in evolution. Geographic isolation occurs whenever a physical barrier divides a population. o A new species can evolve when a population has been geographically isolated. Reproductive isolation can result in speciation o Reproductive isolation occurs when formerly interbreeding populations can no longer mate and produce fertile offspring. o A change in chromosome numbers ( polyploidy ) can lead to speciation.

26 Topic: Speciation Rates Objective: Describe isolation processes in evolution. Gradualism is the idea that species originate through a gradual change of adaptations. o Evidence from the fossil record supports gradualism. In 1972, Niles Eldredge and Stephen J. Gould proposed a different hypothesis known as _punctuated equilibrium_. o This hypothesis argues that speciation occurs relatively quickly, in rapid bursts, with long periods of genetic _equilibrium_ in between.

27 Name: Period: Carefully remove this sheet from your packet to hand in. Work silently and alone to complete this graded exercise. Check for Understanding 1. Summarize the concept of an evolutionary adaptation. 2. Why is insecticide resistance an easily observable natural selection process? 3. Describe a type of evolutionary isolation that could occur if a new multi-lane highway was built through an environment. 4. Briefly compare gradualism and punctuated equilibrium.

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29 Notes page: