Temporal sequences
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Temporal Sequences. Maggie Koopman and Erik Hoffmann. 1.5 billion years. 0.0. Now!. Time is on my side. First hard parts. 1.0. First multicellular. 2.0. First eukaryotes. 3.0. First life!. 4.0. The beginning!. The Outcrop. Sometimes you have a lot to work with. The Outcrop.

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Temporal Sequences

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Temporal sequences

Temporal Sequences

Maggie Koopman and Erik Hoffmann


Time is on my side

1.5 billion years

0.0

Now!

Time is on my side

First hard parts

1.0

First multicellular

2.0

First eukaryotes

3.0

First life!

4.0

The beginning!


The outcrop

The Outcrop

Sometimes you have a lot to work with...


The outcrop1

The Outcrop

...and sometimes you don’t!


The outcrop2

No crystalline rocks

2 meters = 10 yrs or 10 million?

The Outcrop

  • No absolute dating

  • Imprecise age calibration

Dooley et al., 2004


The outcrop3

The Outcrop

Unconformities

  • Stratigraphic gaps caused by non-deposition or erosion

  • The bigger the time window, the bigger and more frequent the gaps will be

Dooley et al., 2004


The outcrop4

The Outcrop

Cover

  • Prevents examination

    • vegetation

    • loose sediment/soil

    • snow/ice/permafrost

Dooley et al., 2004


Temporal sequences

The (so-so) Outcrop


Temporal sequences

2.5 Ma

100 km

Constant Motion

Modified from Tibert et al., 2003.


No outcrop

No Outcrop!


Temporal sequences

  • Resolution depends on depositional rates

    • High rates allow high resolution

    • Low rates allow low resolution

    • Negative rates erase the record

  • Not all environments are created equal!

Schindel, 1982


Temporal sequences

Dooley et al., 2004


Temporal sequences

Gingerich, 1983


Limitations

Limitations

  • Preservable hard parts only!

  • Morphological change only!


Limitations cont

Limitations cont.

  • Can’t detect fine changes.

  • Small directional changes followed by reversals show up as variability within the population

Geary et al., 2002


Temporal sequences

Punctuated Equilibrium

  • Long periods (relative to species durations) of morphological stasis coupled with brief periods of very rapid morphological change

  • Stasis does NOT mean nothing is happening

    • Changes in soft parts

    • Changes in tolerances/behaviors

    • Small directional morphological change followed by doubling back


Temporal sequences

Biases

  • Lineage (size, hard parts, frequency)

  • Location (range, availability)

  • Temporal resolution ((sub)stage level)

  • Character sets

  • Usefulness/Interest


Does the fossil record need to be complete

Does the fossil record need to be complete?

Can we work around the gaps?

Can we derive viable sequences from a spotty record?


Quality of the fossil record through time m j benton m a wills and r hitchin

Quality of the fossil record through timeM. J. Benton, M. A. Wills and R. Hitchin


What does this paper do

What does this paper do?

  • Offers evidence that the fossil record provides uniformly good documentation of past life.

  • Assesses the congruence between stratigraphy

    and phylogeny.


The congruence metrics

The Congruence Metrics

  • Valid techniques for comparing large samples of cladograms to try to estimate variations in congruence between the fossil record for different groups of organisms and for different habitats

  • RCI (relative completeness index)

  • GER (gap ratio index)

  • SCI (stratigraphic consistency index)

Depend on branching point estimates and calc. Of ghost ranges


Stratigraphic consistency index huelsenbeck 1994

Stratigraphic consistency index(Huelsenbeck 1994)

  • Fit of the record to the tree= proportion of the nodes that are stratigraphically consistent.

  • Significance of the fit= generate a null distribution for SCI under the hyp. That the statigraphic fit is not better than expected at random.


Temporal sequences

Figure 2


Temporal sequences

  • Hypothesis 1: congruence is better than random (bars to the left)

  • Alternative hypothesis: congruence is worse than expected from a random model: direct conflict between data (bars to the right)

RCI

SCI

Fig 1 a/b Benton et al 1999


What causes poor matching of age and clade data bias in the metric

What causes poor matching of age and clade data? Bias in the metric

  • Difference in quality of trees

  • Difference in quality of fossil record

  • Stratigraphic problems

  • Taxonomy

  • Sampling density


Molecular clock divergence estimates and the fossil record of cetartiodactyla

Molecular Clock Divergence Estimates and the Fossil Record of Cetartiodactyla

Jessica M. Theodor

J. Paleontology 78 (1), 2004, p 39-44


Why this paper

Why this paper?

  • Ties molecular clocks to the fossil record

  • Introduces cetaceans and hippopotamids


Molecular clocks vs the fossil record

Molecular Clocks vs. the Fossil Record

  • Artiodactyla/Cetacea split – 60 Ma

    • Earliest fossil whales 53.5 Ma

    • Earliest fossil artiodactyls 55 Ma

  • Odontocete/Mysticete split – 34-35 Ma

    • Rare at 34 Ma, good record ~30 Ma

  • Hippopotamid/Cetacean split

    • Earliest fossil whales 53.5 Ma

    • Earliest fossil hippos 15.6-15.8 Ma

      • Anthracotheres - ~43 Ma

  • New study using one mitochondrial and one nuclear gene sequence


  • Temporal sequences

    Boisserie et al., 2005


    Take home messages

    Take home messages

    • The fossil record is necessary to calibrate molecular clocks (and refute the bad ones)

    • The fossil record fills gaps in phylogenetic trees, allowing us to confirm evolutionary sequences


    References

    References

    Benton, M.J., M.A. Wills, and R. Hitchin 2000, Nature. 403, 534-537

    Benton, M.J. 2001, Proceedings of the Royal Society of London B. 268, 2123-2130

    Boisserie, J.-R., F. Lihoreau, and M. Brunet 2005, Proceedings of the National Academy of Science 102 (5), 1537-1541

    Dooley Jr., A.C., N.C. Fraser, and Z.-X. Luo 2004, Journal of Vertebrate Paleontology. 24 (2), 453-463

    Geary, D.H., A.W. Staley, P. Muller, and I. Magyar 2002, Paleobiology. 28 (2), 208-221

    Gingerich, P.D. 1983, Science. 222, 159-161

    Gingerich, P.D. 1984, Science. 226, 995-996

    Gingerich, P.D. 2002, Cetacean Evolution

    Gould, S.J. 1984, Science. 226, 994-995

    Huelsenbeck, J.P. 1994, Paleobiology. 20 (4), 470-483

    Koch, C.F. 1978, Paleobiology. 4 (3), 367-372

    Levinton, J., L. Dubb, and G.A. Wray 2004, Journal of Paleontology. 78 (1), 31-38

    Lihoreau, F., and J.-R. Boisserie 2004, Journal of Vertebrate Paleontology 24 (Supp. 3), 83A

    Rose, K. 2001, Science. 293, 2216-2217

    Schindel, D. 1982, Paleobiology. 8 (4), 340-353

    Schopf, T.J.M. 1982, Evolution. 36 (6), 1144-1157

    Theodor, J.M. 2004, Journal of Paleontology. 78 (1), 39-44

    Tibert, N.E., R.M. Leckie, J.G. Eaton, J.I. Kirkland, J.-P Colin, E.L. Leithold, and M.E. McCormick 2003, in Olson, H.C. and R.M. Leckie, eds., Micropaleontologic Proxies for Sea-Level Change and Stratigraphic Discontinuities: SEPM Special Publication No. 75, 263-299

    Wills, M.A. 1999, Systematic Biology. 48 (3), 559-58


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