Navigation Links
Fossil study helps pinpoint extinction risks for ocean animals

Durham, NC What makes some ocean animals more prone to extinction than others? A new study of marine fossils provides a clue.

An analysis of roughly 500 million years of fossil data for marine invertebrates reveals that ocean animals with small geographic ranges have been consistently hard hit even when populations are large, the authors report.

The oceans represent more than 70% of the Earth's surface. But because monitoring data are harder to collect at sea than on land, we know surprisingly little about the conservation status of most marine animals. By using the fossil record to study how ocean extinctions occurred in the past, we may be better able to predict species' vulnerability in the future.

"If the patterns we observed in the fossil record hold for species living today, our results suggest that species with large populations but small ranges are at greater risk of extinction than we might have expected," said study co-author Paul Harnik of the National Evolutionary Synthesis Center.

Researchers have long assumed that rare animals are more likely to die out. But "rare" could mean multiple things.

The word "rare" could be applied to species that have restricted geographic ranges, or small populations, or that tolerate a narrow range of habitats, or any combination thereof, the authors say.

False killer whales, for example, are considered rare because they occur in small numbers, even though they're found in oceans throughout the world.

Erect-crested penguins, on the other hand, are considered rare because they're geographically restricted to remote islands off the coast of New Zealand even though they're fairly abundant where they occur.

Harnik and colleagues Jonathan Payne of Stanford University and Carl Simpson of the Museum fr Naturkunde in Berlin wanted to know which aspects of rarity best predict why some species survive and others die out.

"It's only through the fossil record where we have a long-term record of extinction where we can really see whether those relationships hold up," Harnik said.

To find out, the team scoured a fossil database for marine invertebrates that inhabited the world's oceans from 500 million years ago to the present a dataset that included 6500 genera of sea urchins, sand dollars, corals, snails, clams, oysters, scallops, brachiopods and other animals.

When the researchers looked for links between extinction rate and measures of rarity, they found that the key predictor of extinction risk for ocean animals was small geographic range size.

Habitat breadth played a secondary role, whereas population size had little effect. The result: Ocean animals that both had small geographic ranges and tolerated a narrow suite of habitats were six times more likely to go extinct than common animals were.

"Environmental changes are unlikely to affect all areas equally, or all individuals at the same time in the same way. If something terrible happens to some part of a species' range, then at least some populations will still survive," Harnik explained.

Life in the sea was once thought to be less prone to extinction than life on land. But with global warming, overfishing, and ocean acidification pushing sea life to its limits, growing evidence suggests otherwise.

"The findings don't mean that when populations dwindle we shouldn't worry about them," Harnik said.

"But the take home message is that reductions in range size such as when a species' habitat is destroyed or degraded could mean a big increase in long-term extinction risk, even if population sizes in the remaining portions of the species' range are still relatively large."

The results will be published this week in the journal Proceedings of the Royal Society B.


Contact: Robin Ann Smith
National Evolutionary Synthesis Center (NESCent)

Related biology news :

1. Protecting living fossil trees
2. Dinosaur fossil: Even specialized predators didnt turn down free meals
3. Seismic zones, river deltas, landslides, fossil reptiles, and more new Geology science
4. Buy coal? New analysis shows purchasing fossil fuel deposits best way to fight climate change
5. Anthropologist finds explanation for hominin brain evolution in famous fossil
6. Ancient giant turtle fossil revealed
7. Scientists find gold-plated fossil solution
8. Human-like spine morphology found in aquatic eel fossil
9. Work starts on fossil fuel free cargo ship set to transform shipping industry
10. Fossil turtle from Colombia round like car tire
11. Fossil egg discovered in Lleida (Spain) links dinosaurs to modern birds
Post Your Comments:
Related Image:
Fossil study helps pinpoint extinction risks for ocean animals
(Date:11/19/2015)... YORK , Nov. 19, 2015  Although some ... market is dominated by a few companies, according to ... companies own 51% of the market share of the ... The World Market for Molecular Diagnostic s ... "The market is still controlled by one company ...
(Date:11/17/2015)...  Vigilant Solutions announces today that Mr. Dick ... --> --> Mr. ... partnership at TPG Capital, one of the largest global ... in revenue.  He founded and led TPG,s Operating Group, ... from 1997 to 2013.  In his first role, he ...
(Date:11/12/2015)... 2015   Growing need for low-cost, easy ... been paving the way for use of biochemical ... analytes in clinical, agricultural, environmental, food and defense ... in medical applications, however, their adoption is increasing ... continuous emphasis on improving product quality and growing ...
Breaking Biology News(10 mins):
(Date:11/28/2015)... ... November 28, 2015 , ... • Jeon Jin Bio ... porcine and rodent control solutions , Bird ... oil, works across all sensory modalities including visual, smell, taste and touch, enabling safe, ...
(Date:11/27/2015)... November 27, 2015 ... popularity of companion diagnostics is one of ... market with pharmaceutical companies and diagnostic manufacturers ... tests. . --> ... report on global cancer biomarkers market spread ...
(Date:11/25/2015)... 2015 --> ... - 2020 report analyzes that automating biobanking workflow ... in long-term samples, minimizing manual errors, improving the ... manual errors such as mislabeling or inaccurate sample ... plays a vital role in blood fractionation, DNA ...
(Date:11/25/2015)... , November 25, 2015 ... cat and human plaque and pave the way for more ... problems in cats     --> ... most commonly diagnosed health problems in cats, yet relatively little ... now. Two collaborative studies have been conducted by researchers from ...
Breaking Biology Technology: