Bio-Diversity

Can evolution run backwards?

Posted by Susan Sharma on July 06, 2006

 
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Can two species that have evolved from one species collapse into one once again? In other words, can evolution run backwards?

Two fledgling species can become different enough genetically so that they can no longer hybridize effectively. But, if the barriers to gene flow come down too soon the two may hybridize and merge again. A recent issue of New Scientist ( 20 May 2006) describes two studies that point to such a possibility. One study relates to two finch ( a small seed-eating songbird) species on the Santa Cruz island ( off the coast of California )-one with large bills and one with small bills-but rarely medium sized ones. This feature reflects two populations specializing in eating two different sizes of seeds. This was in 1960. Four decades later the researchers found that only birds living in sparsely settled parts of the island still showed two different bill sizes. Near the island's only town, birds with middle-sized bills had become more common! The earlier two distinct groups had collapsed into one! What could be the reason for the change? The researchers attribute this to the fact that people are providing bird feeders filled with rice and hence it is no longer a disadvantage to have an intermediate beak! Apparently everybody can eat this rice! Is the impact of human beings on environment forcing evolution into reverse?

Another study relates to Homo Sapiens-human beings. It is really asking who we are and where we came from! True, humans did not evolve from modern apes, but humans and modern apes shared a common ancestor, a species that no longer exists. In other words, we are cousins. Evolution is not a ladder. it is a branching bush. because we shared a recent common ancestorwith chimpanzees and gorillas, we have many anatomical, genetic, biochemical, and even behaviuoral similarities with the African great apes. We are less similar to the Asian apes -orangutans and gibbons- and even less similar to monkeys, because we shared common ancestors with these groups in the more distant past. In this study, genomes of humans, chimps and gorillas were compared using a "molecular clock" to estimate how long ago the three groups diverged. The further back two species diverged, the more differences would have accumulated between their genome sequences. The study suggests that the two lineages split over 6.3 million years ago. But later both the species re-hybridized in a "reverse speciation" event! Complete speciation between humans nad chimpanzees took place less than 6.3 million years. Natural selection then favoured those hybrid individuals whose chromosomes carried fewest of the genes that lower fertility! Evolution just selected what worked! May be, hybridization between the two fledgling species might have provided traits that saved our ancestors from extinction! The growing genomic information should bring us closer to the understanding of the key steps in evolution-the origin of species. Surely every bit of bio-diversity is invaluable. We never know which one would trigger the next innovation. 

Excerpts from article by Dr.V.B.Kamble at

http://www.vigyanprasar.gov.in

 

Climate change and Global Warming

Evolution and Climate change

Posted by Susan Sharma on July 06, 2006

 
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How is it possible for one species to give rise to more than one subsequent species?

One process by which this can occur is through the dividion of a population into two or more smaller populations by a geographical barrier. If the environments of the respective populations differ, different traits will be selected for in each, and the evolution of these populations will follow different courses. As the two groups become isolated from each other, they would stop sharing genes, and eventually genetic differences would increase until members of the groups can no longer interbreed. At this point, they have become separate species and the speciation is complete. Through time, these two species might give rise to new species, and so on through millenia.

 Another process that may give rise to speciation is climate change. When climate changes, species try to follow the climate they are adapted for. Hence they move around the landscape to stay in the same climate space. When they do that, some populations that are left behind might get isolated enough to spur morphological (physical) or genetic changes. One may get a species or population trapped in a region where climate is changing, which would induce a selective force to make them change or become extinct.

 Excerpts from article by Dr.V.B.Kamble

at http://www.vigyanprasar.gov.in

 

Tribal Bill-How it will affect our forests

Tribal Bill 2006

Posted by Susan Sharma on July 04, 2006

 
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The tribal bill provides communities right to protect and manage any "community forest resource" that they have been traditionally conserving and to impose penalties on anyone violating rules.

Sariska was the only reserve with people's participation in the conservation of the tiger. Investigations have revealed that the Bawariya tribes residing within the reserve supported the poachers in Sariska. In Ranthambore, it is well known that the Mogia tribe has been involved in hunting for generations.

Similar knowledge exists for all our national parks and reserves which need to be collated and put to use while formulating the final bill.

 

Interlinking of Rivers

Kolkatta "NO" to interlinking of rivers

Posted by Susan Sharma on July 03, 2006

 
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"There has been a proposal from the Centre to interlink the Teesta, Sankosh and Manas rivers in North Bengal and link it with the Ganga. The objective is to ensure a good supply of water to Bihar, Uttar Pradesh, Gujarat and Rajasthan," said Subhash Naskar, state minister for water resources and irrigation.

However, the state government has decided to oppose the proposed interlinking of the three rivers on two grounds.

First, West Bengal will be deprived of the necessary and adequate water supply for irrigation if the interlinking project materialises.

"This will inevitably jeopardise the agricultural production of the state," said Naskar.

Moreover, the state government apprehends that the proposed interlinking could lead to the destruction of the elephant corridors near the forest areas in North Bengal.

"A number of factors have come into play. Environmental blunders could be a possibility but what one first needs to look at is who the project will serve, how it will be undertaken and whether it is feasible at all," said VK Yadav, Deputy Chief Wildlife Warden, West Bengal.

 http://cities.expressindia.com/fullstory.php?newsid=190307

Eco-tour

Sustainable Travel?

Posted by Susan Sharma on July 02, 2006

 
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It seems that travel related activities account for about 1/3 of greenhouse gas emissions worldwide. In many cases one round trip flight emits more carbon than your automobile does in a year!

Eliminating the damage we do to the planet through travel related activities would be a huge victory in the battle against global warming. To this end, "Natural Habitat Adventures" have announced an innovative new partnership with MyClimate™, a non-profit organization dedicated to fighting global warming through the support of alternative energy projects around the world.

The benefits of this new partnership are simple: When you travel with Natural Habitat Adventures you can actually neutralize the impact of harmful greenhouse gasses that were emitted as a result of your trip.

Here’s how it works. MyClimate™ calculates the emissions from your flight and your Natural Habitat Adventures expedition (primarily from other forms of transportation on your trip). These emissions can be neutralized through the purchase of a MyClimate™ ticket, typically only $10-$50. The MyClimate™ ticket represents an amount of carbon “offsets” purchased from climate friendly projects around the world. The money goes to a local community or businesses in a developing country to help fund more environmentally friendly development options.

For example: let’s say that your flight emits 1.4 tons of CO2, and your MyClimate™ ticket costs $20 (you only pay $10 and Natural Habitat Adventures pays $10). Through MyClimate™ that $20 might be invested in solar ovens in Africa, which will reduce the need to import diesel fuel that would emit the equivalent amount of carbon emissions as your flight.

(http://www.nathab.com/app/cda/nha_cda.php?command=CarbonOffsetting)

 

Tribal Bill-How it will affect our forests

Research Paper-South Africa

Posted by Susan Sharma on June 30, 2006

 
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Research Paper dated 17 Feb 2005 by School of Biological and Conservation Sciences, South Africa

New forest policies in South Africa seek to reconcile conservation and development objectives by devolving some responsibilty for forest management from the state to local communities. Community participation in forest management aims to protect forest-based subsistence livelihoods by incorporating the interests of resource users, while simultaneously diffusing threats to biodiversity by managing resource use.

To date, participatory forest management (PFM) has had mixed success in South Africa because the transfer of rights to users has not accompanied changes in policy. A questionnaire survey of 60 households (43%) revealed the attitudes of users toward current management and conservation options for iGxalingenwa forest. Users chose participatory forest management (52%) over community (25%) or state-dominated forest management (2%) structures.

User choice was motivated by the desire to secure rights of access to, and ensure equitable benefit from, a dwindling resource base, rather than the conservation of these resources to sustain future yields. Users were unwilling to reduce resource use and compromise usufruct rights to achieve conservation goals, even to improve the availability of the resource stock.

Current user needs compromise biodiversity conservation goals, and users regard state conservation practices as protectionist and obstructing their rights of access to resources. While the National Forest Act of 1998 seek to conserve resources by limiting access to them and is based on principles of sustainable use, it is nevertheless perceived to offer few incentives to users to participate in forest management and conservation.

Ideally, an institutional and legal framework that allocates user rights and managerial responsibilities to households is required, but clearlysuitable alternatives to forest produce are also vital for successful management. Greater trust between the provincial parks authority and users is needed, but is complicated by weak traditional leadership and poor community representation.

Ultimately, users preferred PFM because, while recognising that harvest rates are unsustainable, user dependence upon forest resources and weak traditional leadership means they can protect usufruct rights only by participation. Changes to any of these factors may create demands for a new management system. PFM allows the greatest flexibility for responding to changes in demands as well as the environment.

While there is no implementation blueprint that suits every situation, the researchers feel that participatory management of iGxalingenwa forest is the preferred management institution.

However, its success will depend on an improvement on the levels of trust between stakeholders, particularly between users and forest owners(the State). Recognition of community property and access rights is an important prerequisite for participation by users in forest management.

 ( John Robertson and Michael J. Lawes ( 2005), Environmental Conservation 32(1) 64-75)

Tribal Bill-How it will affect our forests

Conservation in Africa

Posted by Susan Sharma on June 28, 2006

 
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Community based conservation projects in Africa have contributed to decreases in poaching. Increase in wildlife game reserves and direct benefits from trophy hunting have promoted a utalitarian, economic approach to conservation at the expense of scientific, ethical and aeasthetic considerations.

Environment Awareness

Animals, agriculture and city planning

Posted by Susan Sharma on June 28, 2006

 
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...The Food and Agricultural Organisation(FAO) of the United Nations recommends urban agriculture including animal rearing within cities as a useful means to tackle poverty and promote sustainable city practices.  It is feared that rapid urbanisation in developing countries will consume about 14 million hectares of cropland by 2020 and make matters worse.  Many African cities and a few European cities are now seriously considering urban agriculture as a viable multifunctional land use strategy.

.........Processed foods increase the ecological footprint of a city, as goods have to be transported from long distances.


The FAO estimates that Delhi will require an additional 1,96,500 trucks of 10 tonne capacity by 2010 to supply food for its population, while Mumbai will need 3,13,400 more trucks.  This will have serious implications for traffic and roads.

.......  Cities that have seriously considered the issues of urban poverty, environment, and food security have made plans to allow for more agriculture within their urban and peri-urban areas.  Bangkok has 60 percent of its metropolitan area as agriculture land, as has Madrid.  Beira in Mozambique has a high percentage of about 88 percent of its green spaces used for family agriculture.  Ottawa has 5,000 hectares of agriculture land within city limits...........

The famous marshes of Xochimilco, located on the outskirts of Mexico City, are fed by treated wastewater from the city.  This water is used for irrigating flowers and vegetables and also recharges the aquifers.....The East Calcutta wetland is an example worth looking at. This 3,900 hectare wetland located in the peri-urban area is used for fisheries.  The many ponds are benefited from the 1,300 million litres of treated wastewater discharged from the city.  About 13,000 tonnes of fish are harvested and about 60,000 people provided a livelihood.  In addition, 150 tonnes of vegetable are also produced daily.  Pigs and ducks are reared as well.........

A.Srivathsan(The Hindu 27 June 2006)

Tribal Bill-How it will affect our forests

A study done in Annapurna Conservation area (Nepal)

Posted by Susan Sharma on June 25, 2006

 
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Community -based approaches to management of protected areas are increasingly being implemented in many areas. In a research study published in the journal Environmental Conservation (2005), the effectiveness of community- based approaches for conservation of biodiversity was examined in Annapurna Conservation Area (ACA) Nepal.

"A combination of ecological and social surveys were undertaken both within and outside ACA, enabling areas under community-based management to be compared with adjacent areas under traditional forms of land use.

Forest basal area and tree species diversity were found to be significantly higher inside ACA, associated with a decline in use of fuelwood as an energy source over the past decade. Social surveys also indicated that wild animal populations have increased inside ACA since the inception of community-based conservation. Observations of animal track counts, pellet counts and direct observations of selected species such as barking deer and Himalayan tahr indicated higher abundances within ACA."

It will be interesting to know the increase/decrease of wildlife population inside ACA before and after adoption of community based management.

( Ref: Effectiveness of community involvement in delivering conservation benefits to the Annapurna Conservation Area, Nepal. by S.B. Bajracharya et.al Environmental Conservation, 32(3): 239-247, 2005)

Tribal Bill-How it will affect our forests

A joke by our 'thinkers'

Posted by Rauf Ali on June 23, 2006

 
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Two astonishing features of the bill leap out: The process: we've wiped out the tiger in some places, so wiping out more habitat will ensure its future, according to the Tiger Task Force. Or should it be 'Task Farce'? More Lucid Logic: Since 10 lakh hectares of forest have already been destroyed after the Forest Conservattion Act was passed, its reasonable to advance the cutoff date for encroachers, etc. to the present, and thus destroy even more forest land. The politicians know what they are doing: expanding their vote banks even if it means the loss of most of our remaining forest. I'm not convinced the so-called tribal rights people have applied their minds to the issue. After all, people are people. Does anybody seriously believe that destruction will stop once control is handed over? Why not actually visit forest areas and spend serious time there in understanding the issues?
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