Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Revisited human-worm relationships shed light on brain evolution

10.02.2011
"Man is but a worm" was the title of a famous caricature of Darwin's ideas in Victorian England. Now, 120 years later, a molecular analysis of mysterious marine creatures unexpectedly reveals our cousins as worms, indeed.

An international team of researchers, including a neuroscientist from the University of Florida, has produced more evidence that people have a close evolutionary connection with tiny, flatworm-like organisms scientifically known as "Acoelomorphs."

The research in the Thursday (Feb. 10) issue of Nature offers insights into brain development and human diseases, possibly shedding light on animal models used to study development of nerve cells and complex neurodegenerative diseases such as Alzheimer's and Parkinson's.

"It was like looking under a rock and finding something unexpected," said Leonid L. Moroz, a professor in the department of neuroscience with the UF College of Medicine. "We've known there were very unusual twists in the evolution of the complex brains, but this suggests the independent evolution of complex brains in our lineage versus invertebrates, for example, in lineages leading to the octopus or the honeybee."

The latest research indicates that of the five animal phyla, the highest classification in our evolutionary neighborhood, four contain worms.

But none are anatomically simpler than "acoels," which have no brains or centralized nervous systems. Less than a few millimeters in size, acoels are little more than tiny bags of cells that breathe through their skin and digest food by surrounding it.

Comparing extensive genome-wide data, mitochondrial genes and tiny signaling nucleic acids called microRNAs, the researchers hailing from six countries determined a strong possibility that acoels and their kin are "sisters" to another peculiar type of marine worm from northern seas, called Xenoturbella.

From there, like playing "Six Degrees of Kevin Bacon," the branches continue to humans.

"If you looked at one of these creatures you would say, 'what is all of this excitement about a worm?'" said Richard G. Northcutt, a professor of neurosciences at Scripps Institution of Oceanography, who was not involved in the study. "These are tiny animals that have almost no anatomy, which presents very little for scientists to compare them with. But through genetics, if the analysis is correct — and time will tell if it is — the study has taken a very bothersome group that scientists are not sure what to do with and says it is related to vertebrates, ourselves and echinoderms (such as starfish).

"The significance of the research is it gives us a better understanding of how animals are related and, by inference, a better understanding of the history of the animals leading to humans," Northcutt said.

Scientists used high-throughput computational tools to reconstruct deep evolutionary relationships, apparently confirming suspicions that three lineages of marine worms and vertebrates are part of a common evolutionary line called "deuterostomes," which share a common ancestor.

"The early evolution of lineages leading to vertebrates, sea stars and acorn worms is much more complex than most people expect because it involves not just gene gain, but enormous gene loss," said Moroz, who is affiliated with the Whitney Laboratory for Marine Bioscience and UF's McKnight Brain Institute. "An alternative, yet unlikely, scenario would be that our common ancestor had a central nervous system, and then just lost it, still remaining a free living organism.

Understanding the complex cellular rearrangements and the origin of animal innovations, such as the brain, is critically important for understanding human development and disease, Moroz said.

"We need to be able to interpret molecular events in the medical field," he said. "Is what's happening in different lineages of neuronal and stem cells, for example, completely new, or is it reflecting something that is in the arrays of ancestral tool kits preserved over more than 550 million years of our evolutionary history? Working with models of human disease, you really need to be sure."

Scientists on the research team include Herve Philippe of the University of Montreal, Henner Brinkmann and Richard R. Copley of the Wellcome Trust Center for Human Genetics in Oxford, Hiroaki Nakano of the University of Tsukuba in Japan, Albert J. Poustka of the Max-Planck Institute in Berlin, Andreas Wallberg of Uppsala University in Sweden, Kevin J. Peterson of Dartmouth College in New Hampshire and Maximilian J. Telford of University College London.

John Pastor | EurekAlert!
Further information:
http://www.ufl.edu

More articles from Life Sciences:

nachricht A novel synthetic antibody enables conditional “protein knockdown” in vertebrates
20.08.2018 | Technische Universität Dresden

nachricht Climate Impact Research in Hannover: Small Plants against Large Waves
17.08.2018 | Leibniz Universität Hannover

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: It’s All in the Mix: Jülich Researchers are Developing Fast-Charging Solid-State Batteries

There are currently great hopes for solid-state batteries. They contain no liquid parts that could leak or catch fire. For this reason, they do not require cooling and are considered to be much safer, more reliable, and longer lasting than traditional lithium-ion batteries. Jülich scientists have now introduced a new concept that allows currents up to ten times greater during charging and discharging than previously described in the literature. The improvement was achieved by a “clever” choice of materials with a focus on consistently good compatibility. All components were made from phosphate compounds, which are well matched both chemically and mechanically.

The low current is considered one of the biggest hurdles in the development of solid-state batteries. It is the reason why the batteries take a relatively long...

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....

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

Quantum bugs, meet your new swatter

20.08.2018 | Information Technology

A novel synthetic antibody enables conditional “protein knockdown” in vertebrates

20.08.2018 | Life Sciences

Metamolds: Molding a mold

20.08.2018 | Information Technology

VideoLinks
Science & Research
Overview of more VideoLinks >>>