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Evidence for Evolution

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Presentation on theme: "Evidence for Evolution"— Presentation transcript:

1 Evidence for Evolution
Honors Biology

2 What is the Evidence of Evolution?
Darwin Argued That Living Things Have Been Evolving On Earth For Millions of Years. Evidence For This Process Could Be Found In: The Fossil Record Biogeography (the Geographical Distribution of Living Species) Homologous Structures of Living Organisms (Comparative Anatomy) Embryology

3 Evidence for Evolution http://www. sumanasinc
Homology a similarities in characteristic traits resulting from common ancestry Anatomical Homologies (Comparative Anatomy) From a common ancestor Called HOMOLOGOUS STRUCTURES Same structure and development, but different function Examples = Vertebrate limb bones, bird feathers/mammal hair

4 Homologous Structures
Homologous structures are structures (body parts) that are anatomically similar structures inherited from a common ancestor but different function.

5 LE 22-14 Human Cat Whale Bat

6 Comparative Anatomy 3) Analogous Structures:
Through convergent evolution Convergent evolution the evolution of a species from different ancestors toward a similar (not the same!) form Structures that perform a similar job, but are not from a common ancestor Example = bird wing, bat wing, and an insect wing

7 4. Vestigial organs remains of structures/organs that ONCE had an importance in organism’s ancestors Example: tailbones in humans, appendix, wings on ostrich, wisdom teeth in humans, nipples in male mammals, femur and pelvis in whales

8 5. Comparative Embryology

9 Embryology Embryology is a new method of examining evidence of evolution Embryo = first 9 weeks of vertebrate development Embryonic structures of different species show significant similarities By studying the same patterns of early development across many different animals, we can find evolutionary links between animals

10 6. Molecular Homologies Similar genes (DNA), RNA or amino acid sequences Example genes shared among organisms inherited from a common ancestor Ex #1: Homeobox is a DNA sequence in genes that regular development in plants, animals and fungi

11 Human Rhesus monkey Mouse Chicken Ex #2: Amino Acid/ Frog
LE 22-16 % of Amino Acids That Are Identical to the Amino Acids in a Human Hemoglobin Polypeptide Species Human 100% Rhesus monkey 95% Mouse 87% Chicken 69% Ex #2: Amino Acid/ Protein sequence Frog 54% Lamprey 14%

12 7. Biogeography the geographic distribution of species Sugar Glider
Marsupial Flying Squirrel Eutherian (placental) Some similar mammals that have adapted to similar environments have evolved independently from different ancestors

13 8. Genetic Changes over time
Bacteria becomes resistant to antibiotics

14 Paleontologists have discovered fossils of many transitional forms
9. Fossil Records Paleontologists have discovered fossils of many transitional forms Shows variety on organism across time

15 The Fossil Record Earth is BILLIONS of years old
Fossils in different layers of rock showed evidence of gradual change over time Paleontologists have discovered fossils of many transitional forms Example- Whales have an excellent fossil record-showing transitional forms

16 The Fossil Record The succession of forms in the fossil record clearly suggests that organisms change through time, and have descended from a common ancestor Different groups appear in the fossil record at different times, with a general trend toward the simplest organisms appearing the EARLIEST

17 RECALL: Evidence for Evolution
Fossil record Comparative Anatomy Homologous structures Analogous structures Comparative Embryology Vestigial structures Molecular biology (DNA/RNA/protein amino acid differences) Biogeography Field studies

18 Natural Selection vs. Artificial Selection
Recall Natural selection In artificial selection, humans modify other species over many generations by selecting and breeding individuals with desired traits

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22 Key Concepts What is the raw material necessary for the mechanism of Natural Selection? Heritable variations What is the smallest unit of evolution? Populations (NOT individuals) Darwin incorporated Lyell’s gradualism into biological evolution combined with Malthus’ observations regarding populations

23 Is Evolution JUST a THEORY??? Is it SCIENCE based?
accounts for MANY observations and data attempts to explain and integrate a great variety of phenomena Video #1: Isn’t Evolution Just a Theory?

24 copyright cmassengale
Cladogram Diagram showing how organisms are related based on shared, derived characteristics such as feathers, hair, or scales copyright cmassengale

25 Outgroups vs. Ingroups Outgroup Ingroup
The species or group of species that is closely related to the ingroup Distinguishes between shared primitive and shared derived characteristics Closely related to ingroup Ingroup the various species we are studying

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27 What is the shared primitive characteristic? Notochord
A Cladogram What is the shared primitive characteristic? Notochord

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29 Lamprey

30 Aminion The amniotic sac is a bag of fluid inside a woman's womb (uterus) where the unborn baby develops and grows. It’s sometimes called the ‘membranes’, because the sac is made of two membranes called the amnion and the chorion.

31 Placenta

32 Foramen magnum


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