Presentation is loading. Please wait.

Presentation is loading. Please wait.

Defined: Collection of every known fossil Most fossils found in sedimentary rock Age determined by depth –Law of Superposition: new rock forms on top.

Similar presentations


Presentation on theme: "Defined: Collection of every known fossil Most fossils found in sedimentary rock Age determined by depth –Law of Superposition: new rock forms on top."— Presentation transcript:

1

2

3 Defined: Collection of every known fossil Most fossils found in sedimentary rock Age determined by depth –Law of Superposition: new rock forms on top of older rock –A.k.a. Relative Dating Evidence Conclusions: –1) Newer fossils are more complex –2) Common ancestors: similarities between ancient & modern life

4 AKA: Transition Fossils –Archaeopteryx: shares both bird & reptile features –Basilosaurus: shares whale & land mammal features –Tiktaalik: shares fish & amphibian features Evidence Conclusion : Indicates common ancestry Reptile Evidence Teeth Bony tail Bird Evidence Wishbone Feathers Whale Evidence Long spine Found in dried up oceans Land Evidence Wolf-like teeth Hind legs Fish evidence Scales Fins Found in dried-up oceans Amphibian evidence Eyes on top of head Wrist bones

5

6 Comparing old fossils to modern life shows change Ancient Kelp Modern Kelp

7 Radiometric Dating Helps determine age of fossils. More accurate than relative dating. Isotopes: atoms of the same element with differing neutrons –Ex: 12 C and 14 C 12 C = 6 protons + 6 neutrons 14 C = 6 protons + 8 neutrons Organisms collect carbon throughout their lifetime. –When organism dies: 14 C starts to decay into 14 N at a known rate (half-life) Fossil age determined by comparing ratio of C to N –Wider ratio = older sample Both are Carbon

8

9 Dating Fossils

10 Geography The study of geography provides evidence of evolution. –island species most closely resemble nearest mainland species –populations can show variation from one island to another

11 Different species show similar development patterns Different body plans become noticeable later in development Evidence Conclusion : Indicates common ancestry

12 Defined: similar body structures with very different functions Different environments lead to adaptations –Ex: The forelimbs of animals Evidence Conclusion : Indicates common ancestry

13 Human hand Bat wing Mole foot Fly wing –Analogous structures are not evidence of a common ancestor. Homologous structures are different than analogous structures –Analogous structures have similar functions but different structures.

14 Defined: Organs or structures which have lost most or all their original function Vestigial Human Parts: –Gill slits = once used to breath oxygen in water –Yolk sac = once used to nourish developing embryo –Tailbone = once used for balance –Appendix = once used to digest plants –Wisdom teeth = once used to grind plant tissue Evidence Conclus ion : Indicates common ancestry

15 Human Embryo w/ Vestigial Structures

16 Pythons have tiny femurs (leg bone)

17 DNA, RNA, proteins compared Genetic code same for most life More related species have more similar biochemistry Evidence Conclusion : Indicates common ancestry

18 Constant creation of chemicals for human use is eliminating the “unfit” (invading)organisms –Ex: Antibiotics eliminating unfit bacteria –Ex: Pesticides eliminating unfit pests –Ex: Antivirals… –Ex: Fungicides… Allows resistant to survive and reproduce

19

20 Antibiotic Resistance Which antibiotics would successfully treat this infection? penicillin ampicillin Amoxycillin tetracyclin vancomycin

21

22

23 How does antibiotic and pesticide resistance show natural selection? How do the following lines of evidence show change over time? –Fossils –Homologous structures –Vestigial structures –Resistant organisms –Embryo development –Biochemical (molecular) evidence Fossil age can be determined two ways. What are they? Which type of anatomical structures do not show evidence of common ancestry?Review


Download ppt "Defined: Collection of every known fossil Most fossils found in sedimentary rock Age determined by depth –Law of Superposition: new rock forms on top."

Similar presentations


Ads by Google