Evolution, PhanerozoicLife and Mass Ex tincti ons
Hilde Schwartz [email protected] Body Fossils
Trace Fossils FOSSILIZED Living bone Calcium hydroxyapatite
Ca10(PO4)6(OH,Cl,F , CO3)2
FilbFossil bone Fluorapatite
Ca10(PO4)6(F,CO3,OH,Cl)2
EVOLUTION
Descent with modification.
…via tinkering with the natural genetic and phenotypic variations found in nearly all biologic
populations. Wollemi pine: zero genetic variability
Evidence: comparative anatomy, molecular genetics, vestigal structures, observed natural selection, and so on. Evolutionary Mechanisms Mutation Gene flow
Natural selection adaptive Genetic drift random
Hawaiian honeycreepers Microevolution
MliMacroevolution Phanerozoic Milestones
Hominids (5-(5-66 Ma) Mammal ‘explosion’ Primates
Birds, Flowering plants
Mammals, dinosaurs, turtles, pterosaurs, etc… Modern corals
Land plant ‘explosion’ Reptiles Amphibians, giant fish, vascular plants Life on land (Plants, insects) ‘Jaws’
Vertebrates (jawless ‘fishes’) Animal ‘explosion’ Drivers of evolution Biological innovations Plate tectonics Evolvinggg global chemistr y Global temperature
Evolution of degradation- resistant vascular plants
Berner, R. A. (2003) The long‐term carbon cycle, fossil fuels and atmospheric composition. Nature 426:323–326. Cool horse Hot horse Patterns of Phanerozoic Evolution
1.9 – 100 million species of macroorganisms Bent o n,
1985
1. Diversity has increased through time Can we trust the fossil record?
Biological characteristics HbittHabitat Taphonomic processes Time The “Pull of the Recent”?
Peters, 2005
Based on data in Sepkoski, 1984 (A), Niklas et al., 1983 (B), and Benton, 1985 (C,D)
Number of species preserved in Lagerstatten Patterns of Phanerozoic Evolution
2. The locus of diversity has changed through
Benton and Harper, 1997 time
0% of macroscopic 8585--9595% of macroscopic species are terrestrial species are terrestrial
Vermeij and Grosberg, 2010 Patterns of Phanerozoic Evolution 3Etiti3. Extinction and origi iinati on rat es h ave ch anged through time
‘Background extinction’ = 2-5 families/million years families ee Extinction rates Origination rates s in marin rr illion yea mm tinctions/ xx E Raup and Sepkoski, 1982 Sepkoski, 1998 Patterns of Phanerozoic Evolution 4. Mass extinctions
Rapid, global and taxonomically broad reductions in the 76% biodiversity of macroorganisms 85% 83% 80% 95%
Proposed by Norman Newell (beginning in 1962)
Substantiated by further quantitative analysis (e.g. Raupand Sepkoski,Sepkoski, 1982) MtitihldbddMass extinctions should be regarded as mass depletions in diversity. Evolutionary Significance of Mass Extinctions
Byyg removing incumbent taxa , extinction frees up ecospace for the diversification of new taxa, and thus be an agent of evolutionary change Recovery from Mass Extinctions Æ evolutionary radiations
Fast or slow? 1.5 – 40 my Possible causes of mass extinctions
1. Glaciation
2. Volcanism (especially LIP eruptions)
3. Sea level change
4. Marine chemistry (anoxia/dysoxia, hypercapnia, euxinia)
5. Climate change
6. Sluggish evolution?
7. Impact
8. One-two punches? And on and on and on…….. There is no common pattern End-Cretaceous (K-T/K-Pg) 76% species extinction Schulte et al., 2010 The question: Was dinosaur eecoxtinction ggduradual or sudden?
Pattern vs causation Hanna Basin Williston Basin Æ Extinction in < or= 10 ky? Why the timing (and hence the cause) of mass extinctions is difficult to ascertain:
Artificial range truncations Patterns of terrestrial vertebrate survival after the K-K-PgPg boundary Counterpoint…. ‘Dracoryx hogwartsia and other latest Cretaceous dinosaur ’ appear to have been over-split
Some dinosaur lineages may have decreased in diversity during the last 5-10 million years of the Cretaceous The Moreno Shale, Panoche Hills How to Survive a Mass Extinction
1. Live in a range of Cretaceous bivalves habitats, across a large area
Jablonski and Raup (1995) 2. Be an ecological generalist, tolerant of diverse conditions
Vampyroteuthis infernalis Ceratites nodosus Brayard et al., 2009 3. Be a minimalist
4. Be lucky change during at least three truly at least three increasing diversity , including at least three truly macroevolutionary biosphere has endured multiple
The Bottom Line extinctions and time ive Phanerozoic, including Phanerozoic biosphere has endured multiple real patterns of the Phanerozoic mass through time mass extinction events without enduring serious damage The Phanerozoic 1. The fossil and rock records, though flawed, show 2. The Alternative Homework Choose a mass extinction other than the K/T event to research and answer the following questions about it:
1. How long did the main extinction event last and how long did it take the biospp(phere to ‘recover’? (Expect more than one opinion.)
2. What is the favored extinction mechanism(s)? What is the evidence therefore?
3. What organ isms ‘ra diated ‘i n th e wak e of the mass extiiinction ?
Your answer should not be longer than 1-2 typed pages. You should cite at least three references (not Wikipedia!) in your text and you must list your references in a ‘Citations’ section following your answers. Some References
Alroy, J. (2008), Dynamics of origination and extinction in the marine fossil record, Proceedings of the National Academy of Sciences of the United States of America 105 Suppl 1:11536–11542.
Alvarez, W., Asaro, F. and Montanari, A. (1990,) Iridium Profile for 10 Million Years Across the Cretaceous‐Tertiary Boundary at Gubbio (Italy), Science 250:1700‐1702
Brayard, A., Escarguel, G., Bucher, H., Monnet, C., Bruhwiler, T. (2009), Good Genes and Good Luck: Ammonoid diversity and the End‐Permian Mass Extinction, Science 325, 1118‐1121.
Dahl, T.W. et al. (2010), Devonian rise in atmosphericoxygencorrelatedto the radiations of terrestrial plants and large predatory fhfish, PNAS, doi///10.1073/pnas.1011287107.
Peters, S. (2004), Relative abundance of Sepkoski’s evolutionary faunas in Cambrian‐Ordovician deep subtidal environments in North America, Paleobiology, 30:543‐ 560.
Raup, D.M., Sepkoski ,Jr., J.J. (1984), Periodicity of extinctions in the geologic past, Proceedings of the National Academy of Sciences of the United States of America 81(3): 801–5.
Schulte, P. et al. (2010), The Chicxulub asteroid impact and mass extinction at the Cretaceous‐Paleogene boundary, Science 327:1214‐1218.
Sepkoski, J.J. (1984), A kinetic model of Phanerozoic taxonomic diversity. III. Post‐Paleozoic families and mass extinctions, Paleobiology 10(2):246‐267.
Sepkoski, J.J. (2002) Compendium of fossil marine animal diversity, Bulletin of American Paleontology 363:1‐560.
Vermeij, G.J. and Grosberg, R.K. (2010), The great divergence: when did diversity on land exceed that in the sea?, Integrative and Comparative Biology, 1‐8, doi: 10.1093/icb/icq078