Directed readings Flashcards
if you were writing an essay about preservation would paper would you use?
Bertazzo et al 2015
- 75 million yr old dinosaurs
- found collagen fibres in the fossil bones
- found that preservation of protein over geological time opens up an opportunity to interpret physiology and behaviour
paper for writing an essay on dinosaurs increasing diversification
Fatovsky et al 2004
- steadily increasing rate of diversification
- disproves decrease in richness running up to the cretaceous
- did genera counts
- south america and asia contribute most to the diversity
paper to describe the bias of the fossil record
Smith 2003 -
- wanted to work out species diversity by removing rock bias
- based on number of geological formations and the area of out-crop available for collection
- conclude that rock outcrop area is more reliable predictor of sampling bias in the fossil record
- continental shelf affects sampling bias
- decide to take fossil record at face value - still provides reasonable representation of past diversity levels
paper for essay on exceptional preservation
Zhou (2003) - jehol china
- feathered theropods and early birds - provides evidence that dinosaurs are ancestors of birds
- rapidly buried organisms in lakes in a microenvironment with anoxic conditions
- feathers and colour preserved - insight into origin of flight
paper on polar dinosaurs
Rich et al 2002
- dinosaurs living at polar latitudes
- looked at Australia and alaska
- oxygen isotopes to gauge average temps - need to establish conditions to interpret polar dinosaurs
- showed absence of cold blooded animals
- high visual acuity
- too small to migrate
- identify promising new location in Alaska for more polar dinosaurs
paper for identifying function and behaviour from fossils
Benton (2010)
- uses 3 approaches
1) empirical evidence - trace fossils, stomach contents, teeth etc
2) comparison with modern analogs - make inferences based on parsimony/phylogenies
3) biomechanical modelling - insight into the moving parts of skeletons can find out how things walked and speed etc
Papers for identifying past environments/co2 levels
Pearson and palmer (1999, 2000 , 2003)
1) all 3 papers use boron isotope ratios from ancient planktonic foraminifer to estimate ph of surface-layer sea water , this is then used to reconstruct atmospheric co2 levels
2) (1999) middle eocene atmospheric co2 was probably similar to modern concentrations , post Eocene cooling was driven by reorganization of ocean currents by tectonic openings/movements
3) (2000) co2 levels since early miocene have remained pretty much constant , suggets that other feedbacks (tectonics changing ocean circulation) were important in determining global climate change
4) (2003) tropical oceans had an important role in the traition from glacial to interglacial climate, study shows that planktonic foraminefera are a powerful tool when interpreting past environments
Paper on fossils and the molecular revolution
Culotta et al 2015
About revolution in ancient DNA sequencing techniques
First success in 1980, but encounter problems with contamination
Initially used PCR, but lots of contamination and slow
Ancient DNA can now be recognised as preferential nucleotide degradation
Is the golden era of ancient DNA analysis
Finding new places to get old sequences, DNA preserved well in petrosal bone in ear
Who wrote papers about palaeobiodiversity?
Barret - 2010 Lloyd - 2008 Wang - 2006 Fatovsky - 2004 Benton 1997
What is Barret 2010 paper about?
Look at how pattens of biodiversity can reveal tempo and mode of evolution
Say quality and amount of rock available has massive impact on the interpretation of patterns
Previos studies have ignored rock megabias - but believe this has less impact than expected
Look at relationship between clade diversity and rock record of mesozoic dinosaurs
Look at if diversity curves are sampling artefact rather than real evolutionary events and compare estimates to observed
Show that most clades have general pattern of increasing diversity
Claims there is evidence for a decline in diversity before the KT
What is Lloyd 2008 paper about?
Looked at whether dinosaurs were part of the cretaceous terrestrial revolution, but conclude that they weren’t
Results show that rapid expansion in dinosaur diversity in the cretaceous is seen due to sampling artefact
Conclude dinosaurs did not decline pre KT mass extinction
Suggest that ghost ranges should account for missing fossil data, and can use this to correct diversity profiles
What is the Wang 2006 paper about?
Study aimed to estimate the total diversity of the dinosaurs
Predicted that 71% of dinosaur diversity hasn’t yet been described, but that 75% of genera will be known in the next 100 years
Suggest that diversity increases steady, and that numbers were not in decline pre KT
See a bias in rock availability, making diversity appear differently
What is the Fatovsky 2004 paper about?
Looked at specific lies riches of the Mesozoic Dinosauria
See a steady rise in diversity, suggest this is due to innovation of behavioural strategies
Shows dinosaurs not going extinct pre KT
Suggest most of the unknown dinosaur diversity can be found in South America and Asia - findings showing a decline come from North American fossils only
What does the Benton 1997 paper show?
Suggests continental organisms have shown an exponential increase in diversity
Look at logistic, exponential and linear models for diversification - chosen models make different claims about evolution
Marine invertebrate diveristiy is logistic, see two plateaus in Cambrian and ordovician
Vascular plants not affected by mass extinction
Insects appear to be exponential
Equilibrium models used to explain diversity (like island models) but look at origination and extinction
Expansion models see clades speciate exponentially
Not clear how models can be replicated at a global level - can be seen in a lab
May be dampening effects at play
What paper is about evolutionary patterns from the fossil record?
Gould et al 1993
Looks at the punctuated equilibrium hypothesis, which says that most evolutionary changes occur during geologically rapid speciation events
Species exhibit stasis most of the time
Cast macroevolution as the differential success of certain species within clades
Says can test the punctuated equilibrium by studying the morphological and taxonomic distribution of organisms, including faunas
