Evolution : Evidence of Change

1. Evolution:Evidence of Change

2. Charles Darwin (1809-1882) • 1831 Set sail on a 5 year voyage on the HMS Beagle around the world, and noted the diversity of life. Found ↑ diversity & similarities w/ adaptations to fit climate, environment, geography • Fitness – A combination of physical traits and behaviors that help organisms survive and reproduce. • Fitness arises fromAdaptationsthat help an organism become better suited for their environment.

3. Question • What EVIDENCE did Darwin find to support his Theory of Evolution?

4. Similarities in Body Structures~Homologous Structures~Structures similar in origin and structure, but show different needs and appearance.

5. ~Vestigial Structures~ Organs that are reduced in sized and no longer function. Appendix- Non-functioning in humans, but in koala bears and rabbits who eat lots of flora, it helps to further digest their food. • Coccyx – tail bone traced to ancestors to support a tail. • Male Nipples – Males & females born with nipples & ducts intact. Presence of genes that direct hormones to differentiate the breast tissue. Other genes on Y-chromosome stimulate testosterone to form male features.

6. ~Analogous Structures~ Structures that are similar in appearance and function, but have different origins. Butterfly – has exoskeleton, forms membranous wing Birds– skeletal structure from which the wing is formed.

7. Similarities in ~Biochemistry~

8. Evidence: similarities of Early Development similar genes at work

9. Embryo Development • As embryo grows & develops similarities disappear caused by genes that have changed with Evolution

10. Mutations +Mutations  adaptation & increased fitness passed on -Mutations  less fit & not passed on

11. Age of EarthContributes to Darwin’s Theory • James Hutton 1788: geologist argued earth very old & changed through gradual weathering, volcanoes, natural forces • Charles Lyell 1830: Earth changed gradually/slowly must be used to explain past events Both used to support Darwin’s Theory of evolution

12. Geological Time Scale

13. Fossilspreserved remains of ancient organisms (paleontology- study of fossils) • Relative Dating: Technique used to determine age of fossils relative to other fossils in different layers of rock (fossils found deeper are older) • Absolute dating: radioactive decay measured in ½ life to determine age of rock. ½ life: length of time required for ½ of the radioactive atoms in a sample to decay. C-14 (1% from env.) ½ life 5500yrs (½x½=¼11,000 yrs U-238 (1/2 life 4.5by) K-40 (1/2 life 1.3by) Fossil Record is INCOMPLETE!

14. What Fossil Record Shows • Evolutionary history of organisms • Changes in Earth’s climate & geography • Organisms simple  complex Fossil Record shows change in living organisms followed changes in Earth

15. Types of Fossilsplants/animals replaced with mineral compounds petrified (turned into rock) • Sedimentary rock particles carried by streams, rivers, lakes, seas  settle & embedded in layers of rocks (older deeper) • Cold trapped in ice • Tree sap/Amber  traps insects • Quicksand, peat bogs, tar pits no oxygen so decomposition is slowed

16. Dragonfly in amber Lizard in amber Frog in amber Prehistoric termites in amber

17. Fly preserved in amber for over 3 million years

19. Fossils - evidence of past life

22. man buried in a peat bog for over 2,000 years

23. An insect trapped in hardened plant sap (amber) Organisms trapped liquid tree sap. Soft body parts stay preserved. Cast of the organism body Like an imprint the shape of living organism is turned into stone leaving the reverse shape.

24. Adaptations Any inherited feature that increases the chance of surviving and reproducing. Morphological – inherited structural, anatomical, or physical change that ↑’s fitness [Ex: Panda’s thumb, fish gills  lungs] Physiological – inherited changes that regulate functions w/in individual Ex. Biochemistry controlled enzymes, hormones that ↑’s fitness Ex: Antarctic ice fish produce chemical antifreeze prevents them from freezing Behavioral– Inherited changes in how an organism acts that ↑’s fitness Reflexes, Instincts, hibernation, migration.

25. Recognized that living things adapted and change over time. Jean Baptiste de Lamark(1744 – 1829)

26. * Desire to Change – Inborn urge to become better fit for environment. [Ex: Moths didn’t know they needed to change color*] FALSE * Use & Disuse - “Use it or Lose it.” Change occurred because organisms could alter their shape by using their bodies in new ways. Organs could increase in size, shape, function, etc., depending on needs. [ Ex: Giraffe’s neck grows to reach the tallest leaves on the trees.]FALSE * Passing on Acquired Traits – If an animal acquired body structures during its lifetime, change could be passed down to its offspring. [Ex: Parent build up muscle to have muscular children.] FALSE Jean Baptiste de Lamark’sTheory of Evolution

27. Charles Darwin’s(1809-1882) Theory of Evolution: • The Age of the Earth ~long periods of time were needed for a species to have evolved from a Common Ancestor.~ Hutton  Earth very old Lyell  events gradual like changes on Earth

28. Charles Darwin’s (1809-1882)Theory of Evolution • Natural Selection – The environment selects what can/cannot survive. Thomas Malthus 1766-1834 ↑ populations  ↑competition for resources Darwin: Survival of the fittest Struggle for existence

29. Natural Selection~Tested~ • Peppered Moths – (early 1800’s) • Most Moth’s were light brown blend, darker moths were eaten by birds. • Industrial revolution produced soot that darkened the trees of England. • Change occurred: Light colored Moths were being seen and eaten by birds. • Dark colored Moths were surviving due to camouflage. (Population of Dark Moths grew). • Increase in Gene Frequency of Dk. Colored Moths in Gene Pool of that area. • Conclusion: Better Camouflage Moths survived according to their Environment.

30. Genetics Artificial Selection – human intervention to ensure only desirable traits are bred. [Ex: livestock, crops, dogs, cats]

31. Genetics & Evolutionary Theory • Darwin did not know how inherited traits were important to his theory of evolution & how they were passed on • Fitness, adaptation, species & evolutionary change defined through genetics • Genes that give “fitness”  survival of the fittest are inherited by offspring • Natural Selection / environment chooses • Genes carry inheritable characteristics, source of random variation for Natural Selection Genetics Drives Evolution

32. Terms • Gene Pool: common group of genes (each gene pool contains a # of alleles/ forms of a gene) w/in a species • Relative Frequency: # of times an allele occurs in a gene pool compared to # of times other alleles for same gene occur (Ex. peppered moth) • Evolutionary change: involves a change in the relative frequency of alleles in gene pool of population of a species • Species: group of similar organisms that can breed/ produce fertile offspring

33. Members of species can breed so share common gene pool. • Allows for genetic changes in 1 individual to be spread through population as individual and ITSoffspring mate • If genetic change ↑ fitness (ability to survive/reproduce) gene will be found in many individuals in population

34. Genetic Drift • The random change in the frequency of a gene. (Chance!) • Seen more in smaller populations. • Larger populations can absorb the drift in frequency. • May result when an individual of a certain allele produces more offspring vs. others by chance. • Polydactyl- have +5 digits on fingers or toes.

35. Solve for genetic drift A species of fox live on a mountainside There are an equal number of tan fox & tan fox with purple spots There are an equal # of males & females for each group Color has nothing to do with fitness Give 2 examples with explanations of how genetic drift could occur. Remember it’s random/chance

36. Divergent Evolution 1 species gives rise to many different species that are similar internally, but not in physical appearance. Speciation–How new species evolve from old ones  diversity. separation of populations, don’t interbreed separation of gene pool in one group that doesn’t show in another….leads to 2 distinct species Natural selection increases differences between separated populations. *Adaptive Radiation* 1 species gives rise to may. Organisms evolve a variety of characteristics that enable them to survive in different niches. Homologous Structures (same origin) Divergent Evolution = Adaptive Radiation

37. Speciation • Niche: how organism uses its resources and place where it lives (habitat) • Species: can breed fertile offspring & share common gene pool

38. Process of Speciation • Reproductive Isolation: separation of population  separates gene pools so adaptations in 1 group don’t appear in another  2 species Results from: Geographic barriers (rivers, mtns, streams, roads, etc) prevents breeding Behavioral Isolation Temporal Isolation (mating times) Natural Selection ↑ differences between separated populations  physical & behavioral barriers  different gene pools  new species b/c they no longer interbreed

39. Darwin’s Finches >14 species on Galapagos islands evolved from single S. American mainland ancestral species All exhibit body structures & behaviors that enable it to live in different niche

40. Speciation of Darwin’s Finches • Some finches separated from mainland (lost, blown off course, storm) travel to Galapagos Islands • Separation of Populations (gene pool separates) • Over time each population adapts to needs of their environment (beaks size, shape, etc) • Reproductive Isolation: gene pools no longer mixed  speciation

41. Sharing the Island • New species can coexist if occupy different niches • Extinction if occupy same niche (no 2 species can occupy same niche/ competition leads to extinction of 1 • Further evolution in a species so they occupy different niche (different food source/shelter/resources so ↓ competition

42. Convergent Evolution • A process in which organisms not closely related independently inherit similar characteristics while evolving in separate ecosystems but similar environments Analogous Structureshave differentorigins and structures, but similar function. • Ex 1:The flippers of whales & the fins of fish. • Ex 2:Butterfly wings & Birds wings. • Ex 3:Shark (fish gills) & dolphins mammal lungs

43. Punctuated EquilibriumPattern of long, stable periods interrupted by brief periods of change. • Existence of mass extinctions is not direct evidence of punctuated equilibrium but rather periods of extremely rapid and/or catastrophic environmental change

44. Gradualism • James Hutton showed through sedimentary rock, petrified fossils created a Fossil Record. Fossil Record provides evidence that evolution was slow and gradual. • Charles Darwinbelieved in gradualism organisms adapted and changed over long periods of time. He supported Hutton’s work.

45. Gradualism vs Punctuated Equilibrium Gradualism: slow change over long periods of time Punctuated Equilibrium: long periods of no change followed by periods of rapid change. (catastrophic events)

46. Microevolution • Evolution witnessed Bacterial resistance and new strains Mutations occur that enable bacteria to evolve & outsmart antibiotics  favorable adaptation for bacteria  survival of the fittest  natural selection Reproduce quickly with many offspring  change/evolution that can be seen

47. Evolution of Man (Homo sapiens)Hominid: Member of the evolutionary line that produced humansClassified in Family Hominindae

48. CladogramsDiagram that shows evolutionary relationships among a group of organisms Dinosaurs evolved from thecodonts. Crocodiles, dinosaurs, birds all arose from early reptiles called thecodonts.