Todd A. Radenbaugh, PhDResearch FellowCanadian Plains Research Center

Paleontology in Decline:Making Fossils Live Again

Geological Society of America16-19th,October, 2005

Salt Lake City, UT

Evolution Under Siege

On May 5, 1925, biology teacher John Scopes was arrested for teaching Darwin's theory of evolution in violation of

Tennessee state law.

August 11, 2005

NEW Monkey Trials

http://www.theonion.com

Pennsylvania school board's

decision to teach both intelligent

design and evolution

Apr 2004

New Mexico Schools C

ould Enter

Battle Over 'In

telligent D

esign'

(The Washington Post)

By Martha Raffa

ele, Page A07,

October 09, 2005

Geologist wanted:Posted January, 2005 from:

COLLEGE OF ARTS AND SCIENCES- Dr. R Hawkins, Dean.

Geology: Ph.D. required. Teaching Introductory Geology, Paleontology, and History of Life.

Contact:Liberty University1971 University Boulevard, Lynchburg, Virginia 24502

434-582-2000

New Vision of the Future?

Compatibility with a young-earth creationist position required…

http://www.liberty.edu/Administration/HumanResources/index.cfm?PID=4353

Making Paleontology Relevant

Paleontology courses need to be made more relevant in geology and environmental science departments’ curricula.

• The economy is dependent on fossil fuels.• Anthropogenic forced climate change, habitat loss, and alteration of natural selection pressures has caused extinctions and extensive changes.

No longer concentrate on only morphology and taxonomy.

Paleontology in Virginia

Virginia Universities – Bachelor Programs

Public (n=15)Geology Programs = 5 (33%)Geology Classes = 12 (80%)

Paleo Classes = 7 (47%) College of William and Mary (2)

George Mason UniversityJames Madison University

Old Dominion University (2)Radford University (2)

University of Mary WashingtonVirginia Tech (2)

Private (n=22)Geology Programs = 1 (5%)Geology Classes = 12 (55%)

Paleo Classes = 2 (9%)Virginia Wesleyan College

Washington and Lee

Most Geology classes are Taught in Environmental Studies Departments

37 Virginia Universities – Bachelor Programs

Department Type #

Geology

Paleo classes

6

6

Environmental and Earth Sci.

Paleo classes

16

3 (19%)

Other (Physical sciences, Science survey, etc.)

Paleo classes

3

0

None

Paleo classes

12

0

0

2

4

6

8

10

12

14

16

Geol Paleo

Geology

Env. /EarthSci

Other

No Geol

Retooling Paleontology

• Link recent environmental change to its geologic history• Use evidence from paleoecology and glean lessons for society and economy.

Make room for Paleo and macroevolution classes in the environmental science curricula

Two examples

1. Ediacaran Fauna Reconstruction

• To show different ecological rules of assembly

2. Comparisons between Modern and Paleozoic Ecospace Use

• Extinctions - past and present

Two examples of how to use paleontological theory relevant to today’s environmental science programs:

Ediacaran Fauna Example

650 to 540 Million years ago frond-like forms, jellyfish-like imprints, and trace fossils. Perhaps evolved as nutrient supplies increased in

shallow waters causing a radiation of trophic links in food webs

Photo Credit: http://www.ucmp.berkeley.edu/vendian/critters.html

Garden of Ediacara

A time when today’s rules of ecological assembly did not apply.• No major predators

• Few mobile fauna

• Dominated by suspension feeding

Ediacaran Fauna Clay reconstructions

Ediacaran Fauna

Complete reconstructions of students

Ecospace Example

From Bambach (1983)

Megaguild: Summation of the guilds occupied by a species or group of species.

Ecospace: ecological resources used by species based on adaptive morphologies (bauplan), space utilization, and food sources

Shallow Marine Megaguilds Through Time

Tiering and Bulldozing

-100

-50

0

50

100

C O S D M P P Tr J K T Q

Sed

imen

t-w

ate

r in

terf

ace (

cm

)

Max Above Max below

v

From Ausich and Bottjer 1982

Trace Fossil

Paleozoic Bulldozing – Changes in Ecological Rules of Assembly

Crab burrows

Gastropods Pelcypods

Irregular echinoids

Bulldozers Victims

Blastoid reconstruction

Bryozoans

Brachiopods

Sponges

Crinoids Columinals

EpS

SE

nS

DE

nS

SE

NS

D

DE

nSD

P/H

Oth

er

0

0.5

1

1.5

2

2.5

Imp

ort

ance

Val

ue

Magaguild

Recent

Mississippian

Ecospace Comparisons of a Modern and Late Paleozoic Assemblage

Megaguild KeyEpS = Epibenthic suspensionSEnS = Shallow endobenthic suspensionDEnS = Deep endobenthic suspensionSENSD = shallow endobenthic surface depositDEnSD = Deep endobenthic surface depositP/H = Predator or Herbivore

Ecosystem Stability

Assemblage restructuring.1. Changing resource use -> new organisms create or occupy new niches and guilds.2. Guild decline and species extinction -> Decline or loss of old niches and guilds.3. Speciation -> Vacant niches are filled by newly evolved species, some are similar to previous ones but new guilds cause different assemblage types (change in rules how species associations are structured).

Stable ecosystems: Persistence of similar niches and guilds within species

assemblages, and the same lineages occupy these niches and guilds for extended periods of geological time (3-7 m.y.).

Little selection pressure and speciation.

Are We Changing the Landscape?

What broad scale changes to biotic structure have occurred as a result of human activities similar to those in the fossil record?

Can human activities act as a selection force with the capacity to change the functional roles and assembly rules at the ecosystem level?

Estimation of Vegetation Changes Mixed Grassland Ecoregion of Saskatchewan

0 20 40 60 80 100

1990s

Circa 1880

Grassland

Woodland

Wetland

Cultivated

Sources:

Pre-1880 - Archibold and Wilson (1980)

1990s - Statistics Canada, 1986, 1991 and 1996 Agricultural Census and the South Digital Land Cover

Adapted form Bambach (1985)

Ecospace for Birds

Foraging MethodDabbler

Diver

Gleaner

Picker

Prober

Sallier

Stalker

Swooper

Foraging HabitatBrush/woodland

Grassland

Wetland

Other

Nesting HabitatCavity

Cliff

Ground

Floating Mat

Vegetation

DietSeeds

Omnivore

Aquatic-invertebrates

-vertebrates

-vegetation

Terrestrial-invertebrates

-vertebrates

-vegetation

Bird Assemblages Comparisons1990s

Present Absent

Present 108 2Circa 1900 Absent 25 0

Match Coefficient = 0.80

Total Species = 135

* Calculated using the Shannon-Weiner index : the relative abundance score was substituted for number of individuals.

Circa 1900 1990’s

Species Richness 110 133

Species Diversity* 1.89 2.11

Horn’s Index of Similarity* = 0.77

Guild and Habitat Trends

Guild Type Guild Habitat Trend Guild trendForaging Habitat Brushland/woodland + +0.69

Grassland - -0.29Wetland - -0.19Other + +0.35

Nesting Habitat Cavity + +0.81Cliff + +0.60Ground - -0.21Floating Mat - -0.24Vegetation + +0.44

**

*

**

***

Significance: ** p<0.01; *p<0.05 by Mann-Whitney test

Extinction rate 100 to 1,000 times more rapid than before human domination – one species every hour to minute• “…two-thirds of all species of plants, animals and organisms could be lost in the second half of the next century.” Peter Raven, 2003

Similar scale those in the fossil record.At this rate we may loose 20% of families or 55% of species in the next 100 years.

From Raup and Sepkoski 1992

Extinctions

Extinction Recovery

How long does it take to recover from a mass extinction event?

The origination rate peaks about 20 million years after the peak in extinction rates

From Sepkoski's 1998

Conclusions

Using paleoecology analogs, we can show that current trends are changing the landscape in terms of:

resource use regional species composition

Evolution’s influences on the biosphere, atmosphere, oceans, and solid earth making it a key topic in environmental science departments.

Paleontology tell us how ecosystem structure has changed, and how it might change.

Regional natural selection forces are diversifying and evolutionary changes as seen in the fossil record may be occurring.

Future?

If current declining trends towards paleontology continue,

there will be negative long-term consequences to science and society

in understanding our future.