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  1. Evolution

  2. Think ThinkThink Tell me what you think evolution is?

  3. Evolution of life video Circle the correct answer on the quiz as you see the information on the video VIDEO: EVOLUTION

  4. Charles Darwin Charles Darwin: the father of evolutionary theory. He observed many things on the voyage of the BEAGLE, a ship that travelled around the world. The Beagle traveled to remote areas such as the Galapagos Islands and South America, also Asia and Europe.

  5. Charles Darwin On his voyage Darwin noticed: • That fossils he collected in S. America of giant armadillos that were extinct, similar, but were not identical to modern armadillos. • That in the Galapagos Islands, different species of finches (birds) collected on the islands, had similar, but not identical beak size and shape. The shape and size seemed to tailored to their diets.

  6. Charles Darwin Darwin also noticed that the species were similar but not identical between the Galapagos and S. America. He theorized that species in the Galapagos descended from species in South America. Specifically with the finches, he thought that all the species of finches descended from 1 common species and were modified over time. This is how he explained the differences between the different species.

  7. Darwin's Finches w/ different shaped beaks

  8. Charles Darwin Darwin reflected on his observations over time and did not put out his theories right away. He published his work “Origin of Species” long after his initial voyage. Darwin’s main ideas: Evolution: biologically speaking is the process by which a species changes over time. Natural Selection: traits that make it easier for a population to survive, are passed on to future generations, this is the mechanism or driving force behind the process of evolution.

  9. NATURAL SELECTION 1(Copy info where ever) Individuals with favorabletraits are more likely to leave more offspring better suited for their environment. Again this is called natural selection • Example: English peppered moth (Bistonbetularia) - light and dark phases

  10. NATURAL SELECTION 2 Black mutation in the species became favorable after air pollution. Normal (Speckled) coloring was advantageous before industrial revolution.

  11. Charles Darwin Darwin’s influences Lamarick: proposed that organisms changed over time and adapted to their environment. Malthus: an economist that theorized that population growth which increased exponentially could not keep increasing because the food supply only increased linearly.

  12. Summary New Slide Not in outline Darwin’s 5 points • Population has variations. • Some variations are favorable. • More offspring are produced than survive • Those that survive have favorable traits. • A population will change over time.

  13. Key Terms 1 Population: group of organisms of the same species that live in the same area. Species:group of the same kind of organisms, that can mate and produce fertile offspring. Fossil: the remains of organisms that lived a long time ago, that are preserved in rock. Fossil record: all known fossils in existence. Science uses this record to study organisms of the past.

  14. Evolution by Natural Selection 4 steps in the process • Overpopulation: all populations produce more offspring than can survive. • Variation: a lot of different traits exist in population • Selection: some traits in a population make it easier for the organisms to survive and breed. • Adaptation: over time these traits become more common with in a population.

  15. Biogeography: The study of the locations of organisms around the world. Often we see what was once a single population that was separated by geography evolve into 2 separate species with different traits adapted to their new environments.

  16. Geographical Isolation: when a population or part of a population becomes separated from another part due to a change in geography, such as the separation of the ancient giant continent PANGEA in the above picture.

  17. Embryology: the study of un-born organisms. This can be useful because many times we can see traits in fetuses, before full development that are similar in different species, this can show the evolutionary relationship between organisms that would not be thought to be related.

  18. Embryos in the top line start off at the very beginning of their life looking very similar, but change dramatically before birth. We can see an evolutionary link by examining the similarities of the embryos that can’t be seen in the developed fetus or organism

  19. Molefoot Batwing Human hand • Anatomy the study of body structure. • Examples of the internal structure of organisms than appear similar can be evidence of a common ancestor. All the above are homologous structures. • Homologous structures are similar in structure but different in function. • Homologous structures are evidence of a common ancestor.

  20. You need to write these in your notes!!!!!!!!! • Vestigial Structures: have no function in present organism but may have had use in ancestral organism. • Analogous Structures: structures with similar functions, but with different evolutionary origins.

  21. Vestigial Structures Remains of hind or rear limbs in whales • Analogous Structures

  22. Analogous Structures Homologous Similar Structure Analogous Similar Function but not origin or structure

  23. Start Here Mon

  24. Key Terms 2 • Microevolution: The process by which traits in a population change over time. Genetic drift: random affects of life that cause the differences in passing on of different alleles from one generation to the next. Migration: movement of individuals in and out of a population

  25. Key Terms 3 Macroevolution: study of the development of new species over time. Information can be gathered by comparing fossil record to the living organisms. Convergent evolution: environment influences 2 different species into having similar adaptation Adaptive Radiation: splitting of a species to eventually develop into 2 or more new species.

  26. Convergent evolution: describes evolution toward similar traits in unrelated species.

  27. kit fox red fox ancestor • Divergent evolution describes evolution toward different traits in closely related species.

  28. Key Terms 4 • Extinction: when a population or a species fails to reproduce or dies off. This often has happened in the fossil record • Gradualism: many small changes w/ in a species or population over a long time. • Adaptive Trait: a new characteristic developed as a result of evolution usually is beneficial.

  29. Examples of Variation Australian Dessert Shrub What are the examples of variation here?

  30. Population Genetics Microevolution is studying the change in allele frequency in a population, this can also be called POPULATION GENETICS. Speciation is the creation of a new species from a pre-existing one, through variation (change in alleles). Variations, in genetic terms occur through random mutation of alleles (DNA). If it occurs in a germ or sex cell then the new allele or trait is put out into the entire population through reproduction If the allele and the trait gives an organism an advantage then that allele will be carried to future generations and may eventually spawn a new species.

  31. Key Terms 5 Gene Pool: all the possible alleles shared by a given population. All the genetic possibilities in the populations KEY CONCEPT A population shares a common gene pool.

  32. bald eagle migration Key Terms 6 Gene Flow: the movement of alleles between populations, usually through migration. Gene flow occurs when individuals join new populations and reproduce.

  33. Key Terms 7 Genetic Equilibrium: a population with no genetic change occurring. This was demonstrated by the Harvey-Wienburg Model These populations are said to be not evolving • Genotype frequencies stay the same if five conditions are met. • no genetic drift • no gene flow • no mutations • no sexual selection • no natural selection:

  34. Key Terms 8 Non Random Mating: preferences when choosing a mate, this will change the genotypic ratio or allele frequency of the population. This change will not be RANDOM. Bottle Neck effect: Genetic drift that occurs as a result of a drastic reduction in population by an event having little to do with the usual forces of natural selection.

  35. Genetic drift changes allele frequencies due to chance alone.

  36. Cheetah Bottleneck • The cheetah suffers from genetic homogeneity (Nearly genetically equal)due to a "bottleneck" effect, which occurred approximately 10,000 years ago simultaneous with the last Ice Age.  • As a result, the inbreeding of the few surviving individuals at that time created a genetic monomorphism and a real danger for the loss of the genus due to any sudden, environmental change.  • Genetic variation is considered essential to the long-term survival of an organism as it is acted upon by natural selection

  37. FOUNDER EFFECTNew Slide Genetic drift resulting from the colonization of a new location by a small number of individuals. IE: A small group of ground squirrels from an existing population are relocated to a new habitat. This original “FOUNDERS” of the new population are the entire gene pool.

  38. Key Terms 9 Adaptive Trait: Characteristics organism which enables or enhances the probability of that organism surviving and reproducing. Stabilizing Traits: characteristics of organism or population that tends to produce an equilibrium in the population. Behavioral Isolation: when an organism or population acts in a way that separates it from the rest of the population. (breeding calls, mating dances,)

  39. Behavioral Isolation: LEOPARD FROGS Isolation by mating song Plains Leopard Frog 02   Chiricahua Leopard Frog 12

  40. Key Terms 10 • Two or more species can evolve together through co-evolution. • evolutionary paths become connected • species evolve in response to changes in each other

  41. Species can become extinct. • Extinction is the elimination of a species from Earth. • Background extinctions occur continuously at a very low rate. • occur at roughly the same rate as speciation • usually affects a few species in a small area • caused by local changes in environment

  42. Extinction ( ADD TO OUTLINE) • Humans can cause extinction of a species through overharvesting, pollution, habitat destruction, introduction of new predators and food competitors, overhunting, and other influences. Approx 784 species extinctions due to humans since 1500. White Lemuroid Possum Passenger Pigeon

  43. Informational All is not as bleak as it sounds there are new species found every year. One of the newest is theVaranusbitatawa, a new species of monitor lizard


  45. Classification of Life It is necessary to name and classify organisms , this process is called TAXONOMY. Scientific Nomenclature: A “language” or method used to name different species. Originally many different “languages” were being used and it was very confusing. In the 1750’s Carl Linnaeus developed a system of binomial nomenclature. Binomial: 2-names

  46. Classification of Life 2 Naming Rules: • This system is to name the organism with 2 words, GENUS, SPECIES • 2 part scientific name: genus: a shared group name with others species: specific descriptive name, species names are unique no 2 are the same

  47. Example Wolves and Coyotes Canislatrans: Coyote Canis lupus: Grey Wolf Genus Canis

  48. EXAMPLES Red Maple Tree------- Acer rubrum Humans --------------- Homo sapiens Cats-------------------- Felisdomesticus Lions -------------------- Pantheraleo Tiger -------------------- Pantheratigris

  49. The Linnean System • The Linnean System: Classifies animals and plants into by using decreasing levels of hierarchy bases on how similar they are in structure and form. • DOMAIN: organized by the 3 Cell types, organelles present, Multi or Unicellular . • Eukarya , Bacteria or, Archaea • KINGDOMS: 6, usually defined by number of cells, body organization, or nutrition. Eubacteria, Protista, Archae-bacteria, Fungi, Plantae, Animalia

  50. 3 Domains from a common ancestor