Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Genetic Patterns of Deep-Sea Coral Provide Insights into Evolution of Marine Life

24.10.2012
Patterns Also Shed Light on How Environmental Disturbances Affect Aquatic Organisms
The ability of deep-sea corals to harbor a broad array of marine life, including commercially important fish species, make these habitat-forming organisms of immediate interest to conservationists, managers, and scientists. Understanding and protecting corals requires knowledge of the historical processes that have shaped their biodiversity and biogeography.

While little is known about these processes, new research described in the journal Molecular Ecology helps elucidate the historical patterns of deep-sea coral migration and gene flow, coincident with oceanic circulation patterns and events. The investigators propose a scenario that could explain the observed evolutionary and present-day patterns in certain coral species. The findings can help scientists determine how climate change and other global processes have affected ocean habitats in the past and how they might do so in the future.

“The information generated in this study provides critical baseline data with which the potential effects of disturbances, such as global warming and ocean acidification, on populations inhabiting earth’s largest biome can be assessed,” says first author Santiago Herrera, a PhD candidate at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution (WHOI). The research will also provide new opportunities to examine ancient migration patterns of other marine organisms.

Herrera and his colleagues have been investigating ancient deep-water coral migration patterns from various seamounts—geological features that rise at 1,000 meters or more from the seafloor and often form long chains—and other hard-bottom habitats such as canyons, fjords, and continental slopes. The investigators’ analyses involve the utilization of museum specimens, some of which date back to the mid 19th century.

This latest study focused on one species of coral: Paragorga arborea, also known as bubblegum coral. This coral has been found at polar, subpolar, and subtropical regions of all of the world’s oceans. Few studies have evaluated the overall genetic diversity of widespread deep-sea species, and researchers have wondered whether Paragorgia arborea is in fact a single species on a global scale or whether it has evolved into a set of ‘cryptic’ species, in which they exist as a set of genetically distinct species that are morphologically indistinguishable.

“Analysis of eight gene regions from more than 100 individual corals, collected worldwide over the last 134 years, revealed evidence that individuals collected in regions separated by tens of thousands of kilometers at depths ranging from 100 to 1,500 meters belong to the same species,” says co-author Timothy Shank, an associate scientist at WHOI and Herrera’s mentor. “This genomic and sampling coverage represents an unprecedented effort towards solving fundamental evolutionary questions in deep-water corals,” he adds.

The team also found significant differences in the genetic composition of the populations of this species, indicating that individuals from each population are much more likely to reproduce locally with neighboring individuals, rather than with individuals from other populations elsewhere. “These differences can be explained by the spatial separation of different ocean basins; however, depth does not seem to be an important structuring factor,” says Herrera. “We identified five main populations: North Atlantic, Southern Indian, South Pacific, Western North Pacific, and Eastern North Pacific.”

Surprisingly, the researchers found that populations of Paragorgia arborea from the North Atlantic share a more recent historical connection with the southern hemisphere populations, rather than with the North Pacific populations, which are much closer geographically. This connection seems to have occurred during the late Miocene - early Pliocene period. Other researchers studying different marine organisms such as spiny dogfishes and bryozoans, also known as moss animals, have found this same historical genetic diversity pattern. Furthermore, the findings are consistent with the latest ocean circulation models for the epoch.

These results from the deep sea stand in marked contrast with the hypothesis of a trans-Arctic interchange, which suggests a recent migratory connection between the North Pacific and North Atlantic based on the distribution of several shallow-water organisms such as red algae, sea stars, bivalves, gastropods, barnacles, and seagrass.

“There were many bubblegum coral specimens available from northern locations and very few from southern latitudes to test our hypotheses. So, nine years ago we started to search for specimens in the southern hemisphere, and thanks to our collaborators in New Zealand (NIWA) and Australia (CSIRO), we were able to gather a numerous collection of Paragorgia specimens from the south that allowed us to perform a robust global analysis,” says senior author Juan Sanchez, director of the marine molecular biology laboratory of the Universidad de los Andes, in Colombia.

Moving forward, the scientists plan to expand their research. “The next steps from this study will be to test what small-scale environmental factors produce the differences we see in the genetic composition of neighboring populations—such as the Western and Eastern North Pacific populations—and to try to identify specific adaptations of populations of this species that live at the environmental extremes of its distribution, for example at very shallow and deep depths, and in conditions of relatively low and high pH,” says Herrera.

They also plan to study whether the historical connectivity patterns seen in Paragorgia arborea are found in other deep-sea species, which will give them a better understanding of the origin of the biological diversity present deep within the oceans.

Paragorgia arborea is a conspicuous and locally abundant coral species that can grow massive colonies, which can reach up to 8 meters in height and can be hundreds of years old. (NOAA/MBARI)


The bubblegum coral Paragorgia arborea plays an important ecological role generating microhabitats for numerous species; they are the structural analog of large trees in a rain forest. (NOAA/MBARI)

"The observed genetic diversity patterns, and the inferred evolutionary history of origin and spread of Paragorgia arborea could explain the current distribution patterns of many other marine taxa, for example deep-sea coral symbionts, such as brittle stars and squat lobsters, and thus might have played an important role shaping existing deep-sea faunal diversity," says Herrera.

This research was based on work supported by the Global Census of Marine Life on Seamounts Project (CenSeam), the Facultad de Ciencias - Department of Biological Sciences of the Universidad de los Andes, the National Systematics Laboratory of NOAA’s National Marine Fisheries Service, the Smithsonian Institution, the Systematics Association, the Linnean Society of London, and the Sigma Xi Research Society.

The Woods Hole Oceanographic Institution is a private, non-profit organization on Cape Cod, Mass., dedicated to marine research, engineering, and higher education. Established in 1930 on a recommendation from the National Academy of Sciences, its primary mission is to understand the oceans and their interaction with the Earth as a whole, and to communicate a basic understanding of the oceans' role in the changing global environment.

Originally published: October 23, 2012

WHOI Media Relations Office | EurekAlert!
Further information:
http://www.whoi.edu

More articles from Ecology, The Environment and Conservation:

nachricht How does the loss of species alter ecosystems?
18.05.2017 | Deutsches Zentrum für integrative Biodiversitätsforschung (iDiv) Halle-Jena-Leipzig

nachricht Excess diesel emissions bring global health & environmental impacts
16.05.2017 | International Institute for Applied Systems Analysis (IIASA)

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

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

Im Focus: Can the immune system be boosted against Staphylococcus aureus by delivery of messenger RNA?

Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.

Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....

Im Focus: A quantum walk of photons

Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

Im Focus: World's thinnest hologram paves path to new 3-D world

Nano-hologram paves way for integration of 3-D holography into everyday electronics

An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

 
Latest News

How herpesviruses win the footrace against the immune system

26.05.2017 | Life Sciences

Water forms 'spine of hydration' around DNA, group finds

26.05.2017 | Life Sciences

First Juno science results supported by University of Leicester's Jupiter 'forecast'

26.05.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>