The Role of Isolation in Speciation: New findings

New research by Professor Roger Thorpe and colleagues Yann Surget-Groba and Helena Johansson, at Bangor University, UK, is turning conventional evolutionary theory on its head. A genetic study of island lizards shows that even those that have been geographically isolated for many millions of years have not evolved into separate species.

The area where the research was done, Martinique in the Lesser Antilles, is composed of several ancient islands that have only recently coalesced into a single entity. The phylogeny and geology demonstrates that these ancient islands have had their own tree lizard species for about six to eight million years.

The scientists genetically tested the lizards for reproductive isolation from one another. They found that these tree lizards are freely exchanging genes and therefore not behaving as separate species. In fact there is more genetic isolation between conspecifics from different habitats than between those lizards originating from separate ancient islands.

The latest findings suggest the potential importance of speciation due to differences in ecological conditions (ecological speciation).

Details of the research appear in the latest issue of journal PLoS Genetics.

Snails to the Rescue of Gorillas

Cross River gorilla (Gorilla gorilla diehli), a subspecies of the western gorilla was thought to be extinct until it was rediscovered in the 1980s. Present populations are restricted to densely forested hills and mountains across the Nigeria-Cameroon border.  It is estimated that only 250-300 Cross River gorillas remains in the wild.  People living near Cross River gorillas poach them as they have no alternative sources of income and food. This makes the survival of the Gorllas very, very difficult.

Wildlife Conservation Society (WCS) has come up with a new plan to protect the Cross River gorilla, from poachers by providing locals with an alternate income from farming snails. Snails? Yes. In Nigeria, snails are a highly sought-after delicacy and can provide the wherewithal to support a family. The snails reproduce quickly and provide high protein. The upfront cost to run a snail farm is about 87 US dollars, whereas profit from 3000 snails sold annually comes to about 413 US dollars. This leaves in the hand of the snail farmer 326 US dollars a year. Poaching a gorilla for bushmeat brings in only about 70 US dollars. This is indeed a very commendable effort by WCS.

If you want to have more details about Cross River gorilla click here

Prickly pear Cactus, the Amazing Water Purifier

A few days back we wrote about water purification using Moringa (Moringa oleifera). On the heels of this piece of information here comes news about water purification using Prickly pear Cactus (Opuntia ficus-indica) found worldwide. This is not exactly new information. 19th-century Mexican communities were using Prickly pear Cactus as a water purifier and then it went in to limbo.

It was a team of researchers from University of South Florida that came up with the latest findings. The team extracted the cactus's mucilage and mixed this with water to which they had added high levels of either sediment or the bacterium Bacillus cereus. The mucilage acted as a flocculant, causing the sediment particles to join together and settle to the bottom. This also caused the bacteria to combine and settle. 98 per cent of bacteria were filtered from the water.

Full details appear in the latest issue of journal Environmental Science and Technology

Removal of Sediment and Bacteria from Water Using Green Chemistry

Audrey L. Buttice^†, Joyce M. Stroot^‡, Daniel V. Lim^‡, Peter G. Stroot^§ and Norma A. Alcantar*^†

Department of Chemical and Biomedical Engineering, Department of Cell Biology, Microbiology, and Molecular Biology, and Department of Civil and Environmental Engineering, University of South Florida, Tampa, Florida 33620

Hermit Crabs and their Social Networking

May/June 2010 issue of the journal Behavioral Ecology available online, charmed me no end. It has some incredible info on the social networking of hermit crabs. It is a study of hermit crabs by biologists at Tufts University's School of Arts and Sciences and the New England Aquarium and it has given us a better understanding of social interactions among hermit crabs.

Hermit crabs require empty snail shells for shelter. As they grow bigger they need to find new shells. When there aren't enough suitable shells to go around and some hermit crabs have to go naked. This makes them very vulnerable to predators. So they invariably have to go and scout for new homes if they are to survive in the hostile environment.

When a new shell becomes available, crabs gather around it and queue up in a line from largest to smallest. Once the largest crab moves into the vacant shell, each crab in the queue latches on to the newly vacated shell in front of them.  A chain of shell vacancies is created that ultimately leads to many crabs getting new shells. This is indeed a very carefully crafted housing policy.

A Conservation Therapy Programme from Scotland

Scotland's chief medical officer, Dr Harry Burns, is plumbing for a new prescription to improve the nation's health. Get back to nature and get well. He advocates outdoor activities like organic gardening and forest improvement to combat a range of diseases.  According to the doctor exercise rates in Scotland are notoriously poor and needs improvement.

The chief says outdoor pursuits should become part of mainstream treatment for conditions such as obesity, heart diseases and mental health. Pilot projects have brought a reduction in suicidal tendencies among mental-health patients and a fall in cigarette smoking. A conservation therapy programme involving manual work in the forest at Chatelherault Country Park, Hamilton, South Lanarkshire, is aimed at people suffering from drug and alcohol misuse.

Encouraged by the results from the pilot projects the authorities are trying to get these activities incorporated into mainstream health service delivery system of Scotland.

New Genetic Evidence Supporting the Theory there are Several Species of Killer Whales

The latest issue of the journal Genome Research, has an article where scientists report finding strong genetic evidence supporting the theory there are several species of killer whales (Orcinus orca).

Differences in behavior, feeding preferences and subtle physical features had the scientists postulating that there could be several species of killer whales. The scientists got the proof from using a relatively new method called, 'highly parallel sequencing' to map the entire genome of the cell's mitochondria from a worldwide sample of killer whales.

Two types of killer whales in the Antarctic that eat fish and seals, respectively, are suggested as separate species, along with mammal-eating "transient" killer whales in the North Pacific. Several other types of killer whales may also be separate species or subspecies, but for conclusive evidence additional analysis is required.

Using old technique the examination of mitochondrial DNA genome in one sample could have taken several months. But with the use of high throughput sequencing, researchers can complete the same analysis for 50 or more samples in just a few weeks.

According to the scientists understanding how many species of killer whales there are is critically to establish conservation priorities and to better understand the ecological role of killer whales in the world's oceans.

New Caledonian Crows put up an Amazing Display

Till now we thought that the ability to fashion tools are unique to primates. Here comes a surprise from the crows.

Scientists from New Zealand's University of Auckland have found that New Caledonian crows (Corvus moneduloides) are able to use three tools in succession while searching for food. These birds are the only birds known to craft and use tools in the wild.

To extract food from hard-to-reach nooks the crows fashion branches into hooks and tear leaves into barbed probes. The birds can craft new tools even out of unfamiliar materials. This has left the scientists in awe. Yes, we are yet to fathom the full mysteries of nature.

Details of the research is published in the current issue of Proceedings of the Royal Society B

The Science Behind the Raising of the Hood by Cobras.

The latest issue Journal of Experimental Biology has some fascinating information about the science behind the raising of hood by cobras.

By measuring the electrical activity from the snakes' muscles, the scientists were able to zoom in on the precise group of muscles used by cobras to raise the hoods. The rib bones and the muscles that work them are used for the display.

 The scientists wanted to find out the way in which the ribs were freed up to rotate into the presentation position, and how the muscles were used to accomplish display and then return to a relaxed position.

The researchers implanted tiny electrodes into the snake's neck muscles, with the animal anaesthetized. Once the snake recovered the scientist were ready for filming and recording the muscle activity as the animal flared its neck. They found that eight muscles were involved in "hooding".

The scientist say cobras are not the only snakes to hood and want to crack the mechanism behind these other snakes raising of hoods.

Birds making a comeback thanks to farmers

When rare birds make a comeback due to efforts of farmers it is great news. Usually we hear about disappearance of birds due to the activities of farmers. To buck this trend here comes a great story from UK

 

East Yorkshire farmers are celebrating the runaway success of a scheme intended to boost wildlife on their land. They have been working with bird charity the RSPB to help rare species make a comeback in the region.

RSPB volunteers visit farms to record the number of birds each farm has and also to map out their territories. The volunteers discuss ground realities threadbare with farmers and inputs are given to boost the bird population. The Farmers can also utilize the free survey to helps them join Government environmental stewardship schemes, which pay them to care for the countryside.

Some of the bird that have come back in the farms is from RSPB's endangered list, like reed bunting. In many farms the numbers have gradually gone up.

This great scheme is worthy of emulation worldwide.

If you live in UK you can request a free survey by e-mail at volunteer&farmeralliance@rspb.org.uk or call (01767) 680551.

The State of World’s Mangroves

Coastal development, logging, agriculture, and climate change are proving to be the nemesis of mangrove forests. The first ever assessment of mangrove species by the IUCN Red List found 11 out of 70 mangrove species threatened with extinction. Two of them   Sonneratia griffithii and Bruguiera hainesii find a place in critically endangered list. In the past 60 years Southeast Asia has lost 80 percent of its mangrove ecosystems,

In the pursuit of development many countries forget that mangrove forests provide vital ecosystem functions. They conveniently overlook the fact in terms of monetary value, ecosystem services provided by mangroves works out to a staggering 1.6 billion US dollars annually.

Mangroves act as nurseries for a variety of fish and other marine species and act as buffers against erosion. They also provide carbon sequestration. During the 2004 tsunami in Southeast Asia the regions with mangroves suffered less damage than those without.

The study is a timely reminder of the imminent catastrophe. Details of the study appear in the latest issue of journal  PLoS ONE.

The Lemur that Came Back from Oblivion

Research is a primary component in conservation. Here is yet another example of constant research helping conservation. Researchers from McGill University have rediscovered a species of lemur, Sibree's Dwarf Lemur, more than a century after it was last spotted.

Sibree's Dwarf Lemur was first described in 1896, but no follow up measures were taken to study the species. Meanwhile lot of deforestation took place in the area and the species was not seen at all. The belief was that the species has gone extinct.

One dwarf lemurs at Tsinjoarivo, in Eastern Madagascar intrigued Dr Mitchell Irwin of McGill University who was doing explorative research in the area. He had an ankling that it was a new species. Genetic analysis of the species by Linn Groeneveld of the German Primate Center found the lemur to be the Sibree's Dwarf Lemur. Conservationists around the world are elated.

Scientists say without this genetic study, this species probably would have gone extinct in the near future.

Details of the discovery appear in the current issue of the journal Molecular Phylogenetics and Evolution.

The Eel Mystery

A study on eel study published in the online edition of the Journal of Heredity authored by Joshua Reece   a graduate student in biology in Arts & Sciences at Washington University in St. Louis and co-authored by Bowen, Allan Larson, PhD, professor of biology at Washington University and Reece’s advisor, and two biology undergraduate students at Washington University: Kavita Joshi, and Vadim Goz, makes very interesting reading. It is akin to a mystery novel.

Joshua Reece was startled to find seven species eels eating the same thing and, quite literally, living under the same rock. He asks “how cans this happen? Species don’t do that; if they exploit the same niche they don’t diversify, and if they diversify they don’t exploit the same niche.”

Reece and his colleagues collected two species of eels, the undulated moray (Gymnothorax undulatus) and the yellow-edged moray (G. flavimarginatus) from different locations across the Indo-Pacific Ocean, covering two-thirds of Earth’s surface. They were interested in finding out the genetic differences that might indicate interruptions in gene flow among populations of the eels now or in the past. They found both species to be genetically homogeneous across the entire ocean basin.

The mystery now takes a twist. How did these two species and the other 150 species of moray eel in the Indo-Pacific formed separate species?

The mechanism for speciation is geographic isolation. If one group gets separated from the other, by say a mountain range, natural selection and genetic drift gradually remodel the two similar groups into two dissimilar ones. Now we have to see whether there are barriers in the ocean that play the same role in speciation as the mountain ranges do on land. Eastern Pacific Barrier and the Sunda Shelf might be doing this but needs deeper probe.

The scientist looked at selected mitochondrial and nuclear genes and asked whether there were unique alleles of these genes and whether the degree of variance was correlated to geographic separation. They found lots of variation among the eel genes but virtually none of it had any geographic structure.  The same alleles are found in South Africa as you do in Panama.

The scientists are keen to crack the mystery. If both species of eel are able to maintain genetic connectivity across the entire ocean basin, how did the species arise in the first place? When and how did they form separate species if their larvae make them nearly impervious to geographic isolation? Many of eel species share habitat, share distributions and share prey items. When that happens as per rule of thumb one species outcompetes the other and the loser fade in to oblivion. The rules don’t seem to apply to the morays and nobody has a clue to this mystery right now.

All plantations Need Not Necessarily be 'Biological Desserts’

Forest plantations have acquired a bad reputation over the years. They are branded as 'Biological Desserts’. Latest research indicates that this need not be true in all cases. Well-planned biologically diverse plantations can actually alleviate some of the social, economic and ecological burden currently being placed on natural forests. They can also mitigate climate change by sequestering carbon, off-setting deforestation and reducing ecological strain on natural forests according to Alain Paquette from the Université du Québec à Montréal, who co-authored the study with colleague Christian Messier.

The researchers looked at the types of plantations currently in practice, their pros and cons and tried to arrive at the best methods for creating the greatest social, economic and environmental return. The researchers found that plantations were capable of ameliorating the ecological stressors placed on natural forests when used within an integrated forest zoning approach. This is to say is, any increase in plantations has to be matched by protected areas within the same landscape.

Alain Paquette adds “We have to look beyond the rows of uniform trees and evaluate plantations over larger temporal and spatial scales,".  "Well-planned, multi-purposed plantations can help preserve high diversity, old-growth forests that would be cut otherwise.”  "We can do better locally by using biologically diverse, multi-purposed plantations," "Theory and experimental works suggest that even more services could be produced with carefully chosen mixtures of species to promote the optimal use of resources."

By improving plantation design through  less intensive soil preparation, mixed-species vegetation and greater tolerance of other species in long-term maintenance, the researchers believe that plantations can deliver social, economic and environmental services similar to that of natural forests.

"Our goal is to use low intensity forestry practices and increase the proportion of protected land in the area," Paquette says. The researchers hope that their model will support the practical applications of well-planned, biologically-diverse plantations worldwide.

Reference

Alain Paquette, Christian Messier (2010), The role of plantations in managing the world's forests in the Anthropocene. Frontiers in Ecology and the Environment: Vol. 8, No. 1, pp. 27-34.

Toads and Precognition

The latest issue of Journal of Zoology has a very interesting paper on the ability of Common toads to sense an impending earthquake. This discovery has great portents in our pursuit of credible early warning system for earthquake. Nature itself is showing us a way. It also shows yet another reason to protect our biodiversity.

The clear cut evidence comes from the study of a population of toads which left their breeding colony three days before an earthquake that struck L'Aquila in Italy in 2009.  Five days before the earthquake, the number of male common toads in the breeding colony fell by 96%. Usually once they have bred, the male toads remain active in large numbers at breeding sites until spawning has finished.

  The quake was a 6.3-magnitude event. The colony was 74km from the quake's epicenter yet the toads reacted with great alacrity. The study was spearheaded by Dr Grant

This visible change in the toads' behaviour coincided with disruptions in the ionosphere, which researchers detected around the time of the L'Aquila quake using a technique known as very low frequency (VLF) radio sounding. This kind of changes in the atmosphere has been linked by some scientists to the release of radon gas, or gravity waves, prior to an earthquake. In the case of the L'Aquila quake, Dr Grant could not determine what exactly caused the disruptions in the ionosphere. However, her findings point to the fact that the toads can detect something that points to an impending earthquake.

Even though in the past fish, rodents and snakes have been shown to react shortly before earthquakes strikes, this is the first time that an animal has been shown to react to earthquake days in advance.

SOS Blog Post from Uthaman - Help protect this tree to conserve most endangered bird of prey

K.V Uthaman has sent a guest blog post requesting your help in protecting a tree that is used every year by a pair of endangered WHITE BELLIED SEA EAGLE to build nest and lay eggs. Unfortunately this tree stands on private property and the owner wants to sell off his land after hacking the tree. Read on what Uthaman has to say and chip in with your help. Uthman can be contacted at   kvuthaman@gmail.com

WHITE BELLIED SEA EAGLE

Protect this tree to conserve most endangered bird of prey

White bellied sea eagle is an endangered bird of prey and its distribution in southern India is very sparse. The southernmost population is known up to Mahe.

                                           White bellied sea eagle at Mahe

Near Mahe, there is a place called Puthalam. There is a huge mango tree near Puthalam Temple, which is about 35- 40 meters in height. Every year one pair of white bellied sea eagle comes here, build nest and lay eggs on this tree. One or two chicks are reared and they fly off when the young ones are mature enough to fly. The local people have never disturbed the bird all these years. On the contrary they watch the avian guests with fascination. It could very well be the same pair of birds that are coming here for the last many years.      

                                          White Bellied Sea Eagle guarding nest                                                                                                   In previous years, when there is more than one chick, one of them used to fall down from the nest. The fallen chick was carefully reared by one Mr. Venu, who is a tailor by profession and fond of birds. It becomes his head ache to protect the bird and feed them fish even to the tune of Rs. 150/- per day. When the chicks are grown up and ready to fly, Venu allows them to fly off. This year also one chick fell down and it was cared for and reared by Venu      

A White Bellied Sea Eagle Chic that has fallen from the nest at Puthalath and reared by Mr. Venu 

The land in which the tree stands is under private ownership and now the owner wants to sell the land after cutting the tree. The agitated local people approached the owner and requested him not to fell the tree. He agreed not to fell the tree till the chicks are grown up and fly off. Now the birds have flown off after breeding. This tree may be cut any time now. The poor white bellied sea eagle will come here next year also looking for the tree for nesting. The local people vouch that the birds have been coming here, at least for the last 10 to 15 years. 

It is hypothetical but by virtue of their using the tree for the past many years the birds have become more or less the owners of the tree. The question is whether anybody has got the right to cut the tree and destroy the maternal home of this endangered bird. But sadly it is going to happen. It is a big question how to protect this tree and the species which is using the tree during their breeding season. If such trees are felled you could very well imagine the plight of the species. The tree is presently under the threat of axe. It may not be possible to protect the tree with the local initiatives alone. Mahe being part of Pondicherry State, pressure has to be exerted on Government of Pondicherry to protect the tree. We may even have to think of paying compensation to the landowner and acquire the land to protect the tree. 

We seek your help in protecting this tree.

K V UTHAMAN

kvuthaman@gmail.com

White bellied sea eagle with pearl spot brought to feed its young       

     A White Bellied Sea Eagle Chic that has fallen from the nest