Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Study reveals predation-evolution link

11.09.2007
The fossil record seems to indicate that the diversity of marine creatures increased and decreased over hundreds of millions of years in step with predator-prey encounters, Virginia Tech geoscientists report in the Proceedings of the National Academy of Science.

For decades, there has been a debate between paleontologists, biologists, and ecologists on the role of ecological interactions, such as predation, in the long term patterns of animal evolution.

John Warren Huntley, a postdoctoral scientist in the Department of Geosciences at Virginia Tech, and Geosciences Professor Micha³ Kowalewski decided to look at the importance of ecology by surveying the literature for incidents of predation in marine invertebrates, such as clams and their relatives.

“Today, certain predators leave easy to identify marks on the shells of their prey, such as clean, round holes,” said Huntley. “Such holes drilled by predators can also be found in fossil shells.”

The researchers also looked for repair scars on the shells of creatures that survived an attack.

The study was conducted by looking at studies which reported the frequency of drill holes and repair scars in fossil species from the last 550 million years.

First Huntley and Kowalewski found that predation increased notably about 480 million years ago, some 50 million years earlier than previous studies have found. “The earlier studies were based on changes in morphology – predators with stronger claws and jaws and prey with more ornamented shells. We looked at the frequency of attacks, which increased about 50 million years before the changes in armor,” said Huntley.

But the most notable discovery is the observation that the incidence of drill holes and repair scars are strikingly parallel to Sepkoski’s diversity curve for marine invertebrates. This diversity curve, compiled by the late Jack Sepkoski of the University of Chicago, records the origination and extinction of marine animal genera through the last 540 million years (Phanerozoic). “There is a strong correlation between predation intensity and global marine biodiversity in the Phanerozoic,” Huntley said.

In their article, “Strong Coupling of Predation Intensity and Diversity in the Phanerozoic Fossil Record,” the researchers offer three rival hypotheses to explain the correlation. “It’s the classic problem with interpreting a correlation,” said Huntley “you have to be careful when ascribing a cause. Let’s say factors X and Y are correlated. A change in X could cause a change in Y, a change in Y could cause a change in X, or X and Y could both be controlled by another factor.”

The first hypothesis is that predation intensity could be driving diversity. “In this case, ecological interactions would matter in evolution,” said Huntley. “Organisms evolve over the long term in response to their enemies, and with increased predation intensity more species evolve.”

The second hypothesis is that as biodiversity increased, by chance predators with more complex feeding strategies evolved. “Predatory techniques like drilling and peeling shells are more evolutionarily-derived than more primitive forms of predation like whole ingestion. In this scenario you would expect to evolve sophisticated forms of predation only when diversity is high,” said Huntley.

And the third hypothesis is that something else is driving both predation and biodiversity. “Some periods have more sedimentary rocks, and therefore more fossils, preserved than others,” said Huntley. “There is less diversity to be observed when there are fewer fossils to study. Perhaps this sampling bias affects our ability to find samples with high predation intensities as well.”

“Now we will try to pick this apart,” said Huntley. “We can test these hypotheses by examining relevant linkages between predation intensity and diversity in modern oceanic environments. Also, understanding the true nature of Sepkoski’s curve will help us interpret our findings. Is it biological" Is it the product of uneven sampling"

Susan Trulove | EurekAlert!
Further information:
http://www.vt.edu

More articles from Studies and Analyses:

nachricht Study relating to materials testing Detecting damages in non-magnetic steel through magnetism
23.07.2018 | Technische Universität Kaiserslautern

nachricht Innovative genetic tests for children with developmental disorders and epilepsy
11.07.2018 | Christian-Albrechts-Universität zu Kiel

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Color effects from transparent 3D-printed nanostructures

New design tool automatically creates nanostructure 3D-print templates for user-given colors
Scientists present work at prestigious SIGGRAPH conference

Most of the objects we see are colored by pigments, but using pigments has disadvantages: such colors can fade, industrial pigments are often toxic, and...

Im Focus: Unraveling the nature of 'whistlers' from space in the lab

A new study sheds light on how ultralow frequency radio waves and plasmas interact

Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...

Im Focus: New interactive machine learning tool makes car designs more aerodynamic

Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.

When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

Im Focus: The “TRiC” to folding actin

Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.

Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

LaserForum 2018 deals with 3D production of components

17.08.2018 | Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

 
Latest News

Smallest transistor worldwide switches current with a single atom in solid electrolyte

17.08.2018 | Physics and Astronomy

Robots as Tools and Partners in Rehabilitation

17.08.2018 | Information Technology

Climate Impact Research in Hannover: Small Plants against Large Waves

17.08.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>