Evolution, Phanerozoic Life and
M E
Mass
Extinctions
ti ti
Hilde Schwartz
hschwartz@pmc.ucsc.edu
Body Fossils
Trace Fossils
FOSSILIZED
Living bone
Calcium hydroxyapatite
C 10(PO4)
Ca
PO 6(OH
OH,Cl,F,CO
,Cl,F,CO
Cl F CO3)2
F il bone
Fossil
b
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,
anatomy molecular genetics,
genetics
vestigal structures, observed natural
selection, and so on.
Evolutionary Mechanisms
Mutation
Gene flow
Natural selection
Genetic drift
adaptive
random
Hawaiian honeycreepers
Microevolution
M
Macroevolution
l i
Phanerozoic Milestones
Hominids (5(5-6 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
Evolvingg gglobal chemistry
y
Global temperature
Evolution of degradationresistant 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
p
of macroorganisms
Bento
on, 1985
1. Diversity has increased through time
Can we trust the fossil record?
Biological characteristics
H bit t
Habitat
Taphonomic processes
Time
Ti
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
Benton and Harper, 1997
0% of macroscopic
species are terrestrial
85--95%
85
2.
The locus of
diversity has
changed through
time
ti
of macroscopic
species are terrestrial
Vermeij and Grosberg, 2010
Patterns of Phanerozoic Evolution
Exxtinctions/m
million yearrs in marinee families
3 E
3.
Extinction
ti ti andd origination
i i ti rates
t have
h
changed
h
d
through time
‘Background extinction’ = 2-5 families/million years
Extinction rates
Origination
g
rates
Raup and Sepkoski, 1982
Sepkoski, 1998
Patterns of Phanerozoic Evolution
4 Mass extinctions
4.
Rapid, global and
Rapid
taxonomically
broad reductions
in the
biodiversity of
macroorganisms
g
76%
85% 83%
80%
95%
Proposed by Norman Newell (beginning in 1962)
Substantiated by further quantitative analysis (e.g. Raup and Sepkoski,
Sepkoski, 1982)
M extinctions
Mass
ti ti
should
h ld be
b regarded
d d as mass
depletions in diversity.
Evolutionary Significance of
Mass Extinctions
Byy removingg incumbent taxa , extinction frees upp ecospace
p
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)
2.
3. Sea level change
4. Marine chemistry (anoxia/dysoxia, hypercapnia, euxinia)
5. Climate change
6 Sluggish evolution?
6.
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
eextinction
c o gradual
g du
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:
ascertain
Artificial
range
truncations
Patterns of terrestrial vertebrate survival after
the K-Pg 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 yyears of the
Cretaceous
The Moreno Shale,
Panoche Hills
How to Survive a Mass Extinction
Cretaceous
bivalves
1. Live in a range of
habitats, across a large area
Jablonski and Raup
(1995)
2. Be an ecological generalist,
tolerant of diverse conditions
Ceratites nodosus
Vampyroteuthis
infernalis
Brayard et al., 2009
3. Be a minimalist
4. Be lucky
The Bottom Line
1. The fossil and rock records, though flawed, show
real patterns of macroevolutionary change during
the Phanerozoic
Phanerozoic,, including at least three truly
mass ive extinctions and increasing diversity
through time
2. The Phanerozoic biosphere has endured multiple
mass extinction events without enduring serious
damage
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 biosphere
p
to ‘recover’? ((Expect
p more than one
opinion.)
2 What is the favored extinction mechanism(s)? What is the
2.
evidence therefore?
3.
Wh organisms
What
i
‘‘radiated
di d ‘in
‘i the
h wake
k off the
h mass extinction
i i ?
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 atmospheric oxygen correlated to the radiations of terrestrial plants and l
large predatory
d
f h
fish, PNAS, doi/10.1073/pnas.1011287107.
d /
/
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
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