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Assessing the influence of astronomical phenomena on terrestrial biodiversityPowerPoint Presentation

Assessing the influence of astronomical phenomena on terrestrial biodiversity

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Assessing the influence of astronomical phenomena on terrestrial biodiversity

Fabo Feng, Coryn Bailer-Jones

Max Planck Institute for Astronomy, Heidelberg

27.09.2012

Background terrestrial biodiversity

Rohde & Muller, Nature, 2005

Number of genera (thansands)

Biodiversity = Origination – Extinction

Trend + Periodic Oscillation?

Age(Myr)

Claimed astronomical mechanisms terrestrial biodiversity

Perturb Oort Cloud (possibly caused by the motion of the Sun)

Cosmic Ray(Star formation, interstellar magnetic field)

Supernova & GRB

Reviewed in Bailer-Jones (2009)

A possible terrestrial biodiversityconnection between the solar environment and the biosphere

Stellar density

Study the solar motion

Build an orbit-based model

Reference models

Test the model

Data: time series & extinction rate terrestrial biodiversity

Raup & Sepkoski, Science, 1982

Bambach, Annu. Rev. Earth Planet. Sci., 2006

Rohde & Muller, Nature, 2005

Alroy et. al., Science, 2008

stellar density terrestrial biodiversity

Solar motion Orbit-based model

reference models terrestrial biodiversity

Orbit-based model Bayesian inference

data sets

Likelihood = Integral of the normalized extinction rate over the normalized stellar density

Evidence = Averaging likelihood over the parameter space (initial condition)

Evidence ratio = Evidence1/Evidence2

Extinction Rate

Stellar Density

Reference Models: Periodic terrestrial biodiversity

Probability of

observing the extinction time given

the parameters of Periodicmodel

Reference Models: Random terrestrial biodiversity

Probability of

observing the

extinction time given

the parameters of Random model

Reference Models: Uniform terrestrial biodiversity

Probability of

observing the

extinction time given

the parameters of Uniform model

Summary terrestrial biodiversity

- Neither the Orbit-based model nor other reference models are favored over the uniform model
- In particular, no evidence for periodicity in biodiversity data
- Additional information: astroimpacts.org

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