Evaluating Fossil Calibrations for Dating Phylogenies in Light of Rates of Molecular Evolution: A Comparison of Three Approaches (original) (raw)

Journal Article

Vimoksalehi Lukoschek ,

1Department of Ecology and Evolutionary Biology, University of California at Irvine, Irvine, CA 92697, USA

2Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD 4811, Australia

*Correspondence to be sent to: ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD 4811, Australia; E-mail: [email protected].

Search for other works by this author on:

J. Scott Keogh ,

3Division of Evolution, Ecology and Genetics, Research School of Biology, The Australian National University, Canberra, ACT 0200, Australia

Search for other works by this author on:

John C. Avise

1Department of Ecology and Evolutionary Biology, University of California at Irvine, Irvine, CA 92697, USA

Search for other works by this author on:

Received:

17 November 2010

Revision received:

21 January 2011

Published:

11 August 2011

Cite

Vimoksalehi Lukoschek, J. Scott Keogh, John C. Avise, Evaluating Fossil Calibrations for Dating Phylogenies in Light of Rates of Molecular Evolution: A Comparison of Three Approaches, Systematic Biology, Volume 61, Issue 1, January 2012, Page 22, https://doi.org/10.1093/sysbio/syr075
Close

Navbar Search Filter Mobile Enter search term Search

Abstract

Evolutionary and biogeographic studies increasingly rely on calibrated molecular clocks to date key events. Although there has been significant recent progress in development of the techniques used for molecular dating, many issues remain. In particular, controversies abound over the appropriate use and placement of fossils for calibrating molecular clocks. Several methods have been proposed for evaluating candidate fossils; however, few studies have compared the results obtained by different approaches. Moreover, no previous study has incorporated the effects of nucleotide saturation from different data types in the evaluation of candidate fossils. In order to address these issues, we compared three approaches for evaluating fossil calibrations: the single-fossil cross-validation method of Near, Meylan, and Shaffer (2005. Assessing concordance of fossil calibration points in molecular clock studies: an example using turtles. Am. Nat. 165:137–146), the empirical fossil coverage method of Marshall (2008. A simple method for bracketing absolute divergence times on molecular phylogenies using multiple fossil calibration points. Am. Nat. 171:726–742), and the Bayesian multicalibration method of Sanders and Lee (2007. Evaluating molecular clock calibrations using Bayesian analyses with soft and hard bounds. Biol. Lett. 3:275–279) and explicitly incorporate the effects of data type (nuclear vs. mitochondrial DNA) for identifying the most reliable or congruent fossil calibrations. We used advanced (Caenophidian) snakes as a case study; however, our results are applicable to any taxonomic group with multiple candidate fossils, provided appropriate taxon sampling and sufficient molecular sequence data are available. We found that data type strongly influenced which fossil calibrations were identified as outliers, regardless of which method was used. Despite the use of complex partitioned models of sequence evolution and multiple calibrations throughout the tree, saturation severely compressed basal branch lengths obtained from mitochondrial DNA compared with nuclear DNA. The effects of mitochondrial saturation were not ameliorated by analyzing a combined nuclear and mitochondrial data set. Although removing the third codon positions from the mitochondrial coding regions did not ameliorate saturation effects in the single-fossil cross-validations, it did in the Bayesian multicalibration analyses. Saturation significantly influenced the fossils that were selected as most reliable for all three methods evaluated. Our findings highlight the need to critically evaluate the fossils selected by data with different rates of nucleotide substitution and how data with different evolutionary rates affect the results of each method for evaluating fossils. Our empirical evaluation demonstrates that the advantages of using multiple independent fossil calibrations significantly outweigh any disadvantages.

© The Author(s) 2011. Published by Oxford University Press, on behalf of the Society of Systematic Biologists. All rights reserved. For Permissions, please email: [email protected]

You do not currently have access to this article.

Personal account

Get help with access

Institutional access

Access to content on Oxford Academic is often provided through institutional subscriptions and purchases. If you are a member of an institution with an active account, you may be able to access content in one of the following ways:

IP based access

Typically, access is provided across an institutional network to a range of IP addresses. This authentication occurs automatically, and it is not possible to sign out of an IP authenticated account.

Sign in through your institution

Choose this option to get remote access when outside your institution. Shibboleth/Open Athens technology is used to provide single sign-on between your institution’s website and Oxford Academic.

  1. Click Sign in through your institution.
  2. Select your institution from the list provided, which will take you to your institution's website to sign in.
  3. When on the institution site, please use the credentials provided by your institution. Do not use an Oxford Academic personal account.
  4. Following successful sign in, you will be returned to Oxford Academic.

If your institution is not listed or you cannot sign in to your institution’s website, please contact your librarian or administrator.

Sign in with a library card

Enter your library card number to sign in. If you cannot sign in, please contact your librarian.

Society Members

Society member access to a journal is achieved in one of the following ways:

Sign in through society site

Many societies offer single sign-on between the society website and Oxford Academic. If you see ‘Sign in through society site’ in the sign in pane within a journal:

  1. Click Sign in through society site.
  2. When on the society site, please use the credentials provided by that society. Do not use an Oxford Academic personal account.
  3. Following successful sign in, you will be returned to Oxford Academic.

If you do not have a society account or have forgotten your username or password, please contact your society.

Sign in using a personal account

Some societies use Oxford Academic personal accounts to provide access to their members. See below.

Personal account

A personal account can be used to get email alerts, save searches, purchase content, and activate subscriptions.

Some societies use Oxford Academic personal accounts to provide access to their members.

Viewing your signed in accounts

Click the account icon in the top right to:

Signed in but can't access content

Oxford Academic is home to a wide variety of products. The institutional subscription may not cover the content that you are trying to access. If you believe you should have access to that content, please contact your librarian.

Institutional account management

For librarians and administrators, your personal account also provides access to institutional account management. Here you will find options to view and activate subscriptions, manage institutional settings and access options, access usage statistics, and more.

Purchase

Short-term Access

To purchase short-term access, please sign in to your personal account above.

Don't already have a personal account? Register

Evaluating Fossil Calibrations for Dating Phylogenies in Light of Rates of Molecular Evolution: A Comparison of Three Approaches - 24 Hours access

EUR €53.00

GBP £44.00

USD $58.00

Rental

Read this now at DeepDyve

This article is also available for rental through DeepDyve.