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Regents Biology What is Evolution?  changes in living organisms and their genes over time  We KNOW based on evidence and observations  explains how.

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Presentation on theme: "Regents Biology What is Evolution?  changes in living organisms and their genes over time  We KNOW based on evidence and observations  explains how."— Presentation transcript:


2 Regents Biology What is Evolution?  changes in living organisms and their genes over time  We KNOW based on evidence and observations  explains how modern organisms have descended from ancient organisms  Evolution explains BOTH  unity of life - similarities between all living things  AND  diversity of life - wide variety of different creatures on Earth

3 Regents Biology How did we get GRSNERRT?  DNA – codes for _______________  Proteins are made of _______________  Amino acids are coded for by ________  The 3 bases are called _________  Codons are translated using the “Universal” code - works for ALL living things!!!!!!!  UNITY: All creatures have common characteristics Determines ADAPTATIONS

4 Regents Biology DIVERSITY - variation BOTH within a population and the wide variety of living things (remember classification – 6 Kingdoms)  Sexual Reproduction  Two parents contributing genes  In Meiosis – crossing over  New combinations of parents genes  Mutation, mutation, mutation  sometimes beneficial - determines Adaptations

5 Regents Biology Adaptations  Traits that help an individual survive – may not know it’s beneficial  Physical – color, structure  Behavioral – instincts, courtship  Biochemical/physiological – enzymes, sweating, internal characteristics  Born with adaptations – are NOT chosen  GENES determine adaptations (remember genotype determines phenotype)

6 Regents Biology Adaptations NO organisms BECOME adapted They are either born adapted or they are not.

7 Regents Biology What determines survival?  Natural Selection  traits that help individuals survive  survive predators  survive disease  compete for food  compete for territory  traits that help individuals reproduce  attracting a mate  compete for nesting sites  successfully raise young Survival & Reproduction of the Fittest Adaptations

8 Regents Biology  LaMarck  evolution by acquired traits  creatures developed traits during their lifetime  give those traits to their offspring  example  in reaching higher leaves giraffes stretch their necks & give the acquired longer neck to offspring  not accepted as valid Earlier ideas on Evolution

9 Regents Biology Charles Darwin   British naturalist  Voyage of the HMS Beagle  Stopped in the Galapagos Islands  Proposed a way how evolution works  natural selection

10 Regents Biology Voyage of the HMS Beagle  Stopped in Galapagos Islands  500 miles off coast of Ecuador

11 Regents Biology Darwin found: many unique species Different shells on tortoises on different islands Darwin asked: Is there a relationship between the environment & what an animal looks like?

12 Regents Biology Finch?Sparrow? Woodpecker? Warbler? The finches cinched it! Large ground finch Small ground finch Warbler finchTree finch Big seed eaterSmall seed eater Insect eaterLeaf & bud eater Darwin said: Ahaaaa! A flock of South American finches were stranded on the Galapagos… Darwin found: The differences between species of finches were associated with the different food they ate. different beaks are inherited variations serve as adaptations that help birds compete for food these birds survive & reproduce pass on the genes for those more fit beaks over time nature selected for different species with different beaks

13 Regents Biology Darwin’s finches  Darwin’s conclusions  variations in beaks  differences in beaks in the original flock  adaptations to foods available on islands  natural selection for most fit  over many generations, the finches were selected for specific beaks & behaviors  offspring inherit successful traits  accumulation of winning traits: both beaks & behaviors  separate into different species(speciation)

14 Regents Biology Modern Natural Selection  Overproduction – not all offspring will survive  Variation – (3 sources) differences in adaptations (3 types)  Competition – “struggle for survival”  Environment (nature) determines which adaptations are the “fittest”  Best adapted survive and reproduce – pass on the “fit” genes to next generation  The gene pool changes = EVOLUTION – Not the individual

15 Regents Biology 3 Types of Selection  1. Stabilizing  2. Directional  3. Disruptive Niche – organism’s role or “job” in an ecosystem ex: predator/prey, habitat, relationships with other organisms, when it is “active” ONLY ONE (1) species may occupy a niche at a time - total overlap results in “extinction” of the less fit from that ecosystem

16 Regents Biology Stabilizing Selection  Favors the average – decreases variation  Extremes are selected against  Example – spiders - too big: can be easily seen by predators; too small: can’t compete for web building sites

17 Regents Biology Directional Selection  Favors one extreme or the other  Example – finch beaks – small or large food; also peppered moths

18 Regents Biology Witness to Evolution  Peppered Moth  2 types: dark vs. light Peppered moth light

19 Regents Biology Peppered moth  Why did the population change?  early 1800s = pre-industrial England  low pollution  lichen on trees = light colored bark  late 1800s = industrial  factories = soot coated trees  killed lichen = dark colored bark  mid 1900s = pollution controls  clean air laws  return of lichen = light colored bark

20 Regents Biology Disruptive Selection  Favors BOTH extremes at the same time  Leads to speciation – two separate species forming to fill different niches  ONLY one species can occupy a given niche in an ecosystem (increased competition leads to narrower niches)

21 Regents Biology Relationship between species (beaks) & food

22 Regents Biology Other Evidence supporting evolution  1. Fossil record  shows change over time  2. Anatomical record  comparing body structures  homology & vestigial structures  embryology & development  3. Molecular record  comparing protein & DNA sequences  4. Artificial selection  human caused evolution

23 Regents Biology 1. Fossil record  Layers of rock contain fossils  new layers cover older ones  creates a record over time  fossils show a series of organisms have lived on Earth  Link between birds and reptiles  Link between land and sea animals  → supports the idea of a common ancestor  Types:

24 Regents Biology What do we know?  Creatures have changed over time Fossil Record

25 Regents Biology 2. Homologous structures  Structures that come from the same origin  homo- = same  -logous = information  Forelimbs of human, cats, whales, & bats  same structure  on the inside  same development in embryo  different functions  on the outside  evidence of common ancestor

26 Regents Biology 2. Anatomical strucures  The same bones under the skin  limbs that perform different functions are built from the same bones

27 Regents Biology Vestigial organs  Structures on modern animals that have no function  remains of structures that were functional in ancestors  evidence of change over time  some snakes & whales have pelvis bones & leg bones of walking ancestors  eyes on blind cave fish  human tail bone

28 Regents Biology Human vestigial organs  1. a_________________  2. t________ b_______  3. w_______ t_________  No longer have a function or are necessary – may have had a function at one time

29 Regents Biology Comparative embryology  Development of embryo tells an evolutionary story  similar structures during development all vertebrate embryos have a “gill pouch” at one stage of development

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32  We know natural selection can change a population?  we can recreate a similar process  “evolution by human selection” 4. Artificial selection Humans create the change over time “descendants” of the wolf “descendants” of the wolf Video – Evolution in Action – Silver Foxes

33 Regents Biology But don’t be fooled by these…  Analogous structures  look similar  on the outside  same function  different structure & development  on the inside  different origin  no evolutionary relationship Solving a similar problem with a similar solution

34 Regents Biology Convergent evolution led to mimicry  Why do these pairs look so similar? Monarch male poisonous Viceroy male edible flybeemothbee Which is the fly vs. the bee? Which is the moth vs. the bee?

35 Regents Biology For examples of Natural Selection – 1. ID variation in the population 2. ID type of variation (adaptation) 3. ID source of variation 4. ID selecting agent (e___________) 5. individuals with advantageous variations – survive; 6. THEN they get to reproduce 7. State which variation increases and which variation decreases

36 Regents Biology Artificial Selection gone bad!  Unexpected and often dangerous consequences of artificial selection Antibiotic resistance Pesticide (and herbicide) resistance Pesticide (and herbicide) resistance Bacteria Insects And Weeds

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38 Insecticide resistance  Spray the field, but…  insecticide didn’t kill all individuals  variation Insecticide did NOT cause the resistance – it’s the selecting agent  resistant survivors reproduce  resistance is inherited  insecticide becomes less & less effective

39 Regents Biology

40 Antibiotic Resistance

41 Regents Biology REVIEW - Evidence of Evolution  1. Fossils  2. Comparative Anatomy  h______________ structures  v____________  e________________  3. Comparative Biochemistry  ________ and p___________  4. Artificial Selection  b________________  i____________ and a_______________

42 Regents Biology Time Frame for Evolution  Punctuated Equilibrium  Periods of stability followed by periods of rapid change (speciation) OR extinction due to rapidly changing environment  Adaptations must already exist in population

43 Regents Biology Time Frame for Evolution  Gradualism  Slow, continual change due to a more stable environment

44 Regents Biology Oldest Recent or now Species Alive today Extinct Period of stability Change in environment Common Ancestor

45 Regents Biology Evolutionary Time Frame  Evolution is caused by changes in the environment  Natural – caused by nature  Artificial – caused by humans  Ex: pesticide and antibiotics  Evolution is faster with organisms with short life cycles AND lots of offspring  Examples – insects and bacteria

46 Regents Biology Natural Selection - Summary  Adaptations – 3 types: p_________, b________, ph________________  Born with – determined by genes  Variation – 3 sources: s____, c_______ o____, m________; NOT e___________  Competition – struggle for resources (food, shelter, mates) to s_________________  “Fittest” or best adapted are selected for by s___________ a_________ in the e_______________  If “fit” – reproduce and pass on g______  Gene pool evolves (NOT the individual) from selection – 3 types: s___________, d_____________, d____________

47 Regents Biology Summary – One more time  1. Overproduction –  WAY too many offspring are produced  2. Variation –  3 sources -  Adaptations – DO NOT get to Choose  3 types -

48 Regents Biology Summary - Continued  3. Selection – selecting agent  Natural – environment  Artificial – human  → “fittest” survive  4. Reproduction  Pass on “fit” genes →Over time “fit” genes increase → gene pool of a population changes That is EVOLUTION!!!!!

49 Regents Biology Study Guide Vocab, vocab, vocab!!!!!!! Evolution – unity and diversity – p.___ Darwin – Galapagos – p.____ Natural Selection – p. ____ Overproduction Variation in adaptations – 3 types, 3 sources Competition Survival of fittest – 3 types of selection – p._ Evidence of Evolution – 4 pieces – p. ____ Time Frame for Evolution – 3 theories – p. ____

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