Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Discovery Provides New Perspective on Animal Evolution

A new discovery challenges one of the strongest arguments in favor of the idea that animals with bilateral symmetry—those, that like us have two halves that are roughly mirror images of each other—existed before their obvious appearance in the fossil record during the early Cambrian, some 542 million years ago. Groove-like tracks on the ocean floor made by giant deep-sea single-celled organisms could lead to new insights into the evolutionary origin of animals.

Groove-like tracks on the ocean floor made by giant deep-sea single-celled organisms could lead to new insights into the evolutionary origin of animals.

Biologist Mikhail “Misha” Matz from The University of Texas at Austin and his colleagues, including Dr. Tamara Frank with the Center for Ocean Exploration and Deep-Sea Research, Harbor Branch Oceanographic Institute (HBOI) at Florida Atlantic University, recently discovered grape-sized protists and their complex tracks on the ocean floor near the Bahamas. This is the first time a single-celled organism has been shown to make such animal-like traces. The team’s discovery was recently published online in Current Biology and will also appear in the journal’s December 9 print issue.

The finding is significant, because similar fossil grooves and furrows found from the Precambrian era, as early as 1.8 billion years ago, have always been attributed to early evolving multi-cellular animals.“If our giant protists were alive 600 million years ago and the track was fossilized, a paleontologist unearthing it today would without a shade of doubt attribute it to a kind of large, multi-cellular, bilaterally symmetrical animal,” said Matz, an assistant professor of integrative biology. “We now have to rethink the fossil record.”

The National Oceanographic and Atmospheric Administration’s (NOAA) Office of Ocean Exploration and Research provided several years of significant interdisciplinary funding to the research group involved in this discovery (Operation Deep-Scope 2004, 2005, 2007). The NOAA program provided funds for the scientists to explore unknown or little studied regions of the deep-sea floor using HBOI’s Johnson-Sea-Link (JSL) submersible. The JSL provided a nearly 180 degree unimpeded field of view making it possible for the scientists to see the vast field of “grapes” and their tracks during this expedition.

“The unique collecting tools available on the Johnson-Sea-Link allowed us to gather intact specimens from the sea floor at a depth of 750 meters so that Mikhail could analyze them in his laboratory,” said Frank. “It was a ‘eureka’ moment when he realized that these specimens were giant mobile protists and not fecal pellets as we originally suspected.”

Most animals, from humans to insects, are bilaterally symmetrical, meaning that they can be roughly divided into halves that are mirror images. The bilateral animals, or “Bilateria,” appeared in the fossil record in the early Cambrian about 542 million years ago, quickly diversifying into all of the major animal groups, or phyla, still alive today. This rapid diversification, known as the Cambrian explosion, puzzled Charles Darwin and remains one of the biggest questions in animal evolution to this day. Very few fossils exist of organisms that could be the Precambrian ancestors of bilateral animals, and even those are highly controversial. Fossil traces are the most accepted evidence of the existence of these proto-animals.

“We used to think that it takes bilateral symmetry to move in one direction across the seafloor and thereby leave a track,” said Matz. “You have to have a belly and a backside and a front and back end. Now, we show that protists can leave traces of comparable complexity and with a very similar profile.”

With their find, Matz, Frank and their colleagues argue that fossil traces cannot be used alone as evidence that multi-cellular animals were evolving during the Precambrian, slowly setting the stage for the Cambrian explosion. “I personally think now that the whole Precambrian may have been exclusively the reign of protists,” said Matz. “Our observations open up this possible way of interpreting the Precambrian fossil record.”

Matz says the appearance of all the animal body plans during the Cambrian explosion might not just be an artifact of the fossil record. There are likely other mechanisms that explain the burst-like origin of diverse multi-cellular life forms. DNA analysis confirmed that the giant protist found by Matz and his colleagues in the Bahamas is Gromia sphaerica, a species previously known only from the Arabian Sea.

They did not observe the giant protists in action, and Matz says they likely move very slowly. The sediments on the ocean floor at their particular location are very stable and there are no current—perfect conditions for the preservation of tracks. Matz says the protists probably move by sending leg-like extensions, called pseudopodia, out of their cells in all directions. The pseudopodia then grab onto mud in one direction and the organism rolls that way, leaving a track. He aims to return to the location in the future to observe their movement and investigate other tracks in the area.

Matz says the giant protists’ bubble-like body design is probably one of the planet’s oldest macroscopic body designs, which may have existed for 1.8 billion years.

“Our guys may be the ultimate living fossils of the macroscopic world,” he said.

Florida Atlantic University opened its doors in 1964 as the fifth public university in Florida. Today, the University serves more than 26,000 undergraduate and graduate students on seven campuses strategically located along 150 miles of Florida's southeastern coastline. Building on its rich tradition as a teaching university, with a world-class faculty, FAU hosts ten colleges: College of Architecture, Urban & Public Affairs, Dorothy F. Schmidt College of Arts & Letters, the Charles E. Schmidt College of Biomedical Science, the Barry Kaye College of Business, the College of Education, the College of Engineering & Computer Science, the Harriet L. Wilkes Honors College, the Graduate College, the Christine E. Lynn College of Nursing and the Charles E. Schmidt College of Science.

Gisele Galoustian | Newswise Science News
Further information:

More articles from Life Sciences:

nachricht Novel mechanisms of action discovered for the skin cancer medication Imiquimod
21.10.2016 | Technische Universität München

nachricht Second research flight into zero gravity
21.10.2016 | Universität Zürich

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

Im Focus: Ultra-thin ferroelectric material for next-generation electronics

'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.

Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Resolving the mystery of preeclampsia

21.10.2016 | Health and Medicine

Stanford researchers create new special-purpose computer that may someday save us billions

21.10.2016 | Information Technology

From ancient fossils to future cars

21.10.2016 | Materials Sciences

More VideoLinks >>>