Evolution in the Fossil Record: A Case Study of Graptolites

Transcript

1. Evolution in the Fossil Record Alex Clarke A Case Study of Graptolites Monday, 27 February 12
2. What is the Fossil Record The totality of fossilised artefacts and their placement within the earth’s rock strata. It provides information about the history of life on earth, for instance what the organisms look like, where and when they live, how they evolved, etc. Fossil record can provide interesting information about the evolution and the history of life on earth such as the way the particular species have lived during a specific geological period and then evolved in time. — Biology Online Monday, 27 February 12
3. Why we Use the Fossil Record • To look millions of years back in time Monday, 27 February 12
4. Why we Use the Fossil Record • To look millions of years back in time • To see organisms evolving through time Monday, 27 February 12
5. Why we Use the Fossil Record • To look millions of years back in time • To see organisms evolving through time • To learn about the Earth in the past Monday, 27 February 12
6. Why we Use the Fossil Record • To look millions of years back in time • To see organisms evolving through time • To learn about the Earth in the past • To predict what the Earth will be like in the future Monday, 27 February 12
7. Problems with the Fossil Record • Preservation is extremely unlikely Monday, 27 February 12
8. Problems with the Fossil Record • Preservation is extremely unlikely • Certain environments are better for preservation than others Monday, 27 February 12
9. Problems with the Fossil Record • Preservation is extremely unlikely • Certain environments are better for preservation than others • Usually only get hard-parts preserved Monday, 27 February 12
10. — microecos.wordpress.com Monday, 27 February 12
11. Problems with the Fossil Record • Can only see ~600 Million Years • Preservation is extremely unlikely • Certain environments are better for preservation than others • Usually only get hard-parts preserved Monday, 27 February 12
12. Problems with the Fossil Record • Can only see ~600 Million Years • Difficult to determine relatedness • Preservation is extremely unlikely • Certain environments are better for preservation than others • Usually only get hard-parts preserved Monday, 27 February 12
13. A fundamental category of taxonomic classification, ranking below a genus or subgenus and consisting of related organisms capable of interbreeding. Species vs Morphospecies Species Morphospecies A typological species distinguished solely on the basis of morphology. — The Free Dictionary Monday, 27 February 12
14. What is a Graptolite? Monday, 27 February 12
15. — Jan Zalasiewicz Monday, 27 February 12
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17. Stipe Thecae Monday, 27 February 12
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19. Metazoa (Animalia) Eumetazoa Bilateria Deuterostomia Hemichordata Graptolithina Monday, 27 February 12
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21. Metazoa (Animalia) Eumetazoa Bilateria Deuterostomia Hemichordata Graptolithina Monday, 27 February 12
22. 542 Ma 488 Ma Cambrian First Graptolites Monday, 27 February 12
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24. 488 Ma Cambrian Ordovician Dendroid Graptolites Detach from Sea Floor Monday, 27 February 12
25. — fossilmall.com Monday, 27 February 12
26. 488 Ma mbrian 444 Ordovician Reduction in Stipe Number Monday, 27 February 12
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28. 488 Ma an 444 Ma Ordovician Greater reduction in Stipe Number Monday, 27 February 12
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30. 488 Ma 444 Ma Ordovician Stipes open up Monday, 27 February 12
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32. 488 Ma 444 Ma Ordovician Direction of Growth Changes Monday, 27 February 12
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34. 488 Ma 444 Ma Ordovician S Stipes start to fuse Monday, 27 February 12
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36. 488 Ma 444 Ma Ordovician Siluri Graptolite becomes a single stipe with thecae on both sides Monday, 27 February 12
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38. 444 Ma Ordovician 41 Silurian Stipes develop thecae on only one side Monday, 27 February 12
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40. Graptolites Go Extinct 416 Ma Silurian Devonian 359 M Monday, 27 February 12
41. What Does This Matter? Monday, 27 February 12
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43. Jan Zalasiewicz (cue Agata to correct my pronunciation) Monday, 27 February 12
44. What Does This Matter? Monday, 27 February 12