S

Stratigraphy, the Fossil Record

& Adaptive Radiation

Ju Whan Kim, Jacob Finnegan,Richard Kerfoot & Charmaine Chan

BIOL 1510 Module 1Group B-26

Introduction

Stratigraphy

The Fossil Record

Adaptive Radiation

Images obtained from: http://www.micropress.org/stratigraphy/graphics/vol1.jpg, http://www.detectingdesign.com/images/FossilRecord/Time%20Scale.jpg, http://www.cod.edu/people/faculty/fancher/AdapRadB.jpg

Stratigraphy• Study of rock layers and

layering• Two subfields

• Lithostratigraphy• Biostratigraphy

• Focus on Biostratigraphy:• Establish correlations

between time-equivalent rock strata

• What is the purpose?• Related to Fossil Record

and Adaptive RadiationDiagram of Stratigraphyhttp://www.earth-time.org/trollart.html(Earth Time is supported by the National Science Foundation)

What are Arthropods?

Over 90% of the animal kingdom, and found everywhere

Phylum Arthropoda

5 Class Distinctions

Insects Arachnids

Crustaceans

Chilopods Diplopods

Images obtained fromhttp://insected.arizona.edu/arthroinfo.htm

Fossil Record

Traces of animals from the past (Radio-Carbon Dating)

Shows patterns of changes that occurred over time

Relationship deduced and recorded in Phylogenic Trees

Images obtained from: http://evolution.berkeley.edu/evolibrary/images/, http://www.ohiohistorycentral.org/images/256.jpg

Adaptive Radiation

Fast evolution of a lineage to adapt

Marked by increase in number and diversity of species “When a single lineage produces many descendant

species that live in a wide diversity of habitats and use a wide array of resources” (Freeman, 2011)

Ancestor

Images obtained from: http://www.biologycorner.com/resources/spider_labeled.gif, http://www.clemson.edu/cafls/departments/esps/research/adler/images/female3.gif, http://4.bp.blogspot.com/

The Discovery in Italy

Alexander Schmidt found Arthropods fossilized in amber in Italy, approximately 225 – 235 million years old (Schmidt et al., 2012)

Previous: Lebanon, Approximately 125 - 135 Million Years Old. (Koteja and Azar, 2008)

Image obtained from: (Schmidt)

Schmidt’s Data• Traits:

• Left: Detached Mouthparts, Wormlike Appearance.

• Right: Appears Flattened, Larger

• Comparison and Evidence of Adaptive Radiation: • the Arthropods adapted to

their environment and developed distinct characteristics that could place them differently in the Phylogenetic Tree. (Schmidt et al., 2012)

Two Fossilized Arthropods in Amber(Schmidt et al., 2012)

Ancestor

Discussion (Location)• Possible Contributions to

Adaptive Radiation:• From the Triassic to the

Cretaceous Periods, Europe and Asia rotated clockwise.

• Triassic Italy: tropicalTriassic Lebanon: colder

• Cretaceous Lebanon:More mild than the Triassic Lebanon – organisms need to adjust to change in climate

• Schmidt’s findings were similar to an extant species of arthropod found in New Zealand (which during the Triassic, was attached to Australia, which, in turn, was attached to Antarctica) (Schmidt et al, 2012)

The Break-Up of the supercontinent PangaeaUnited States Geological Surveypubs.usgs.gov/gip/dynamic/historical.html

Discussion (Comparison of Mouthparts)

• Time and adaptive radiation leads to a evolution of species.• Why do the species evolve and new characteristics form?

• Habitat Preference• Mutation

•What if separate species?• Species Isolation• Choice of Food

VS.

How can we connect Stratigraphy to the Fossil

Record?

Stratigraphy and the Fossil Record Stratigraphy provides a means to add to the fossil record

The Arthropoda Fossil Record specifically Evolution and change over time Evidence of Location As fossils

Take Home Message!

Biostratigraphy is helpful in determining the history of

arthropods because it permits for the expansion of

their fossil record and the observance of their evolution and adaptive radiation since

they originated.

Literature Cited

Freeman, Scott. 2011. Phylogenies and the History of Life. Biological Science 484, 639-643.

Hanken, James et al. 2004. Modern Biostratigraphy of the Trenton Group. Geologic Overview of the Trenton Group at West Canada Creek, New York. 1-12.

Koteja, Jan and Dany Azar. 2008. Scale Insects from Lower Cretaceous amber of Lebanon (Hemiptera: Sternorrhyncha: Coccinea). Alavesia 2:133-167.

Myrow, Paul et al. 1999. Collaborative Research: Integrated Stratigraphic Study of Cambrian- Ordovican Inner Shelf Facies of the Western United States. National Science Foundation: Grant request.

Schmidt, Alexander. 2012. Arthropods in amber from the Triassic Period. PNAS Early Edition 1-6.