Exploring Paleontology: Uncovering Earth's Fossil Record

2. PaleontologyStudy of prehistoric life Fossils • preserved remains or traces of organisms; • evidence of past life http://evolution.berkeley.edu/evolibrary/article/0_0_0/lines_03

3. Paleontology The Fossil RecordFossils and their placement in rock formations and sedimentary strata http://www.nap.edu/openbook.php?record_id=6024&page=12

4. Paleontology How fossils are formed http://www.wwnorton.com/college/anthro/our-origins2/img/AskClarkFAQs/Figure-8.4.jpg

5. Paleontology • Radiochemistry • Age of the sample is calculated based on the amount of radioactive elements contained • C14  N14 upon an animal’s death • C14>C12 = older organisms • K40 for older samples • Geology • Estimate of fossil’s age in comparison with other fossils • Layers may not have been deposited horizontally or may have been overturned http://evolution.berkeley.edu/evosite/lines/IIIAchronology.shtml

6. Paleontology Fossils link the present with the past • Baleonopteramusculus(blue whale) • Modern marine mammal • Basilosaurus • “king lizard” • w/ 0.5m hind legs, w/ some bones similar to those of land mammals • Ambulocetusnatans • “walking whale that swims” • Skeletons found in Pakistan • Has a long, low body w/ short, powerful limbs • Descended from land-living carnivorous hoofed animals http://www.whale-info.com/bluewhale.html, http://www.bbc.co.uk

7. Paleontology Problems with the fossil record • Fossils form by chance • Quality of fossils varies • Fossil reconstruction requires thorough knowledge of anatomy • Dating of fossils is achieved through various methods http://eweb.furman.edu

8. Comparative EmbryologySimilarities in early development Closely-related organisms have similar stages in embryonic development • Tail • Pharyngeal slits/pouches/arches Shared heritage from a common ancestor! http://www.nature.com/nrg/journal/v7/n11/fig_tab/nrg1918_F2.html

9. Comparative AnatomySimilarities in body structures http://hippie.nu/~unicorn/tut/img/basics/animalanatomy/wing-feathers.jpeg, http://www.uksafari.com/jpeg2/batwing2.jpg, , http://www.bugshop.com.au/images/Butterfly%20Wing.jpg

10. Comparative Anatomy Similarities in body structures and evolution Divergent evolution or adaptive radiation • Common origin • Descendants appear different externally but are similar internally Convergent evolution • Different origins • Descendants independently evolve similarities when adapting to similar environments

11. Comparative Anatomy http://itc.gsw.edu/faculty/bcarter/histgeol/paleo2/limbs.jpg

12. Comparative Anatomy http://www.evolution-textbook.org/content/free/figures/22_EVOW_Art/07_EVOW_CH22.jpg, http://www.carolinabeachtoday.com

13. Comparative Anatomy Vestigial structures • structures that are of marginal or little use to an organism • e.g. coccyx and wisdom teeth in humans, hipbones and pelvis in whales, anal spurs in pythons and boas • evolution is a remodelling process: ancestral structures may be modified as they take on new roles http://3.bp.blogspot.com/-KAdBIaT796A/Ta-KqBdscqI/AAAAAAAAABQ/KWFe8Ks8Oic/s1600/whale-vestigial-structure.jpg, http://en.wikipedia.org/wiki/Anal_spur

14. Biochemistry and Molecular BiologySimilarities in chemical compounds • Similarity of DNA b/w individuals of a species:related individuals > unrelated individuals • Two spp. judged to be closely related by other criteria have a  proportion of their DNA in common than more distantly related spp. A B C D E http://web.scc.losrios.edu/evanst/, http://andfinally.tv/2009/06/baby-gibbon-mothered-247-by-human/, http://www.datensklaven.de/?tag=animals, http://eco-stride.blogspot.com/2007/10/monkey-mobilized-in-columbia.html, http://www.naturalphotos.com/sekercioglu/madagascar/pages/MG8-TnZoo-RTLE.htm ,

15. Biochemistry and Molecular Biology *** • Central dogma of mol bio: • DNA  RNA  proteins • Structure of proteins dictated by DNA sequence • Similar proteins ~ similar DNA sequence ***Hemoglobin: protein that transports O2 in blood

16. Biochemistry and Molecular Biology

17. BiogeographyDistribution of species in space and through time Gondwana broke up around 160 MYA eventually forming modern Antarctica, South America, Africa, Madagascar, Australia-New Guinea, and New Zealand, as well as Arabia and the Indian subcontinent http://planet.uwc.ac.za/nisl/biodiversity/loe/images/pic231.gif

18. Modern species present on a land mass evolved from ancestors that inhabited those regions. • species are not distributed only according to where they can survive http://evolution.berkeley.edu/evolibrary/article/history_16, http://faculty.scf.edu/odaffej/WasDarwinWrong.3/WasDarwinWrongEDIT6.html

19. Islands have many endemic species that are closely related to species of the nearest mainland or neighboring island. http://myweb.rollins.edu/jsiry/c1x17b-finches.jpg, http://www.galapagosisland.net/galapagos_islands/map.html

20. Islands have many endemic species that are closely related to species of the nearest mainland or neighboring island. http://bonvito.files.wordpress.com/2010/11/carlito.png

21. Islands have many endemic species that are closely related to species of the nearest mainland or neighboring island. http://people.eku.edu/ritchisong/birdbiogeography1.htm

22. Wallace Line - imaginary line separating ecozonesof Asia and Wallacea. West of the line are found organisms related to Asiatic species; to the east, a mixture of species of Asian and Australian origin is present. http://people.eku.edu/ritchisong/wallacesline2.gif

23. http://people.eku.edu/ritchisong/554images/Zoogeographical_regions.jpghttp://people.eku.edu/ritchisong/554images/Zoogeographical_regions.jpg

24. http://worldpress.org/images/maps/world_600w.jpg