Chapter 13 / 32

The Theory of Evolution by Natural Selection Charles Darwin Before Darwin: Strong religious power 1800s Lamarck (scientists) believed that organisms change based on needs

What was Thought.. Later Proved Wrong

Topic 1: Darwin’s Mechanism for Evolution 1859 Charles Darwin developed theory of evolution Decades of science observations & experiments Struggled in life: parents, school, religion Interest in natural science conflicted his parents values 1831 HMS Beagle voyage to S. America (5 years) Found evidence that species change over time Fossils Influenced by Malthus (increase in human population Vs food) Charles Lyell (earth geology is changing)

The HMS Beagle Galapagos Islands (off coast of Ecuador) Species there were similar to mainland but not the same “descent with modifications” OR evolution!! Studied many organisms Turtles, Iguanas, Finches most popular

Evolution by Natural Selection Darwin’s association with Malthus: “Natural Selection” Favorable traits are selected for by NATURE NOT THE ANIMAL!!

Evolution by Natural Selection This “selection” or favorable VS unfavorable CAUSES changing in a population (EVOLUTION) Organisms differ from place to place because their habitats change from place to place Form ADAPTATIONS (selective advantage)

examples

Animal Mimicry!

Make 4 Post-its about the notes we took today! Open Notes Pop Quiz! Name a scientists that influenced Darwin’s theory of evolution? What did that scientist do? What was the name of the most famous island Darwin traveled to during his voyage? The favorable traits are selected by___________ for natural selection. What is an adaptation? Finished? Make 4 Post-its about the notes we took today!

Darwin’s Theory of Evolution Published in The Origin of Species SERIOUSLY controversial (humans evolved from apes) 4 Major points to Evolution

4 major points to Theory of Evolution Variation exists within the genes of every population or species (random mutation)

4 major points to Theory of Evolution 2. In a particular environment, some individuals of a population or species are better suited to survive and have offspring

4 major points to Theory of Evolution 3. Over time, the traits that make certain individuals of a population able to survive and reproduce tend to spread in that population

4 major points to Theory of Evolution 4. There is overwhelming evidence from fossils and many other sources that living species evolved from organisms that are extinct (EVOLUTION)

Tempo of Evolution Gradual change over long periods of time Gradualism Rapid change separated by periods of little or no change Punctuated equilibrium

Anatomy and Development Vestigial Structures: evidence of evolution, not used today Homologous structures: share common ancestor because of structure NOT FUNCTION

Notes Quiz What are the 4 points to Darwin’s Theory of Evolution? Give an example of each What are the 2 tempos of evolution? Give an example of each What is the difference between a homologous trait and a vestigial trait?

Do Now: Tigers Whales Turkeys Insects Humans List any examples of evolution found in the following species Tigers Whales Turkeys Insects Humans

NATURE selects the favorable traits! Examples of Evolution NATURE selects the favorable traits! 4 Factors that drive natural selection

Topic 2: 4 factors of Natural Selection All populations have genetic variation

4 factors of Natural Selection 2. The environment presents challenges to successful reproduction

4 factors of Natural Selection 3. Individuals tend to produce more offspring than the environment can support (COMPETETION)

4 factors of Natural Selection 4. Individuals that are better able to cope with environmental challenges tend to leave more offspring than those less suited to their environment

Examples of Evolution Antibiotic Resistance in Bacteria Tuberculosis 1980s, new strains Original drugs Isoniazid and Rifampin don’t work anymore Pesticide Resistance in Insects EID Emerging Infections Diseases!!

Re-Emerging Infectious Diseases

Topic 3: Examples of Evolution Darwin’s Finches 31 specimens 9 with similarities except for beaks Determined by availability of food supply -Damp Year Small narrow -Dry Year Big thick

Formation of New Species Occurs in stages to best “fit” environment Divergence- differences between groups Leads to formation of new species (speciation) Formation of Sub-species Different habitats  different needs difference in species Maintaining New Species Reproductive barriers Timing, geography, physical traits

Review Write this down What are the reproductive barriers when maintaining a new species? Geography, timing, physical traits What are the 4 factors of Natural Selection Adapt or die, competition, nature’s challenges, variation Example of a vestigial trait? Whale hip-bone Example of homologous trait? Bat wing, human arm

The Evolution of Man 32.3 (731-738) Darwin theorized that humans evolved from primates (prosimians, monkeys, apes) because of certain traits Grasping Hands cling to mothers, branches, food Forward Eyes judge distance, depth perception First primates evolved ~50 million yrs ago (MYA)

Non-Human Primates Monkeys & Apes ~36 MYA Monkeys Apes Diurnal (sleep at night, active during day) Detect predators & food Monkeys First primates with opposable thumbs Apes No tail, larger brains DNA of chimpanzee is 95% identical to human DNA

Human Primates (Hominids) Primates that walk upright on 2 legs = hominid species 5-7 MYA Early hominids walked on all fours…why change? “Lucy” is an Australopithecine afarensis 3 MYA Increased brain size Walked upright ~40lbs and 3.5 ft tall

Homo habilis, erectus, sapien Homo habilis = “Handy man” 2MYA Tools & speech Homo erectus = “Upright man” 1.5MYA Evolved in Africa and migrated to Asia Homo sapien = “Wise man” ~200,000 yrs Only surviving of the hominids Modern day human species and genus

VIDEO!!!!! https://www.youtube.com/watch?v=ad0ELPLANWM&feature=related