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

 

Bio-Diversity

Asiatic Lion

Posted by Susan Sharma on May 24, 2006

 
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The Asiatic lion is struggling to survive in its last wild home in India. The Asiatic lion is considered a different species from its African cousin.

Read a well researched article about the Asiatic lion at

Frontline Magazine

Bio-Diversity

Wild Buffalo ( Water Buffalo)

Posted by Susan Sharma on May 23, 2006

 
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With only a few hundreds left in the wild, the wild buffalos (Bubalus Bubalis) in India could soon turn extinct unless an urgent action for their conservation is initiated. Wildlife Trust of India (WTI) in collaboration with the Chattisgarh forest department started a three year plan for its revival from the present small population in the state.

An estimate by the forest department suggests 120 individuals in the state. Udanti WLS is considered to hold the maximum number-about 60 individuals, followed by Indravati NP - about 49 individuals and Pamed WLS about 8 individuals. From the other two, Sitanadi and Baihramgarh Wildlife Sanctuaries considered extinct.

Wild buffalos are said to originate only in two states, Chattisgarh in central India and Assam in northeast India. Assam has the maximum number, about 3000 individuals.

IUCN in 2004 estimated that the total world population is certainly less than 4000 but it may be less than 200 and possibly no pure bred wild Asian buffalo left in the wild. Read the full story at

http://www.wildlifetrustofindia.org/html/news/2006/060215_chattisgarh_story.html

 

Bio-Diversity

Jerdon's Courser

Posted by Susan Sharma on May 23, 2006

 
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Jerdon’s Courser - which is a small nocturnal bird found in the Eastern Ghats of Andhra Pradesh was thought to be extinct till it was re-discovered in 1986. But the Telugu-Ganga Canal Project, which runs through the Sri Lankamaleswara Wildlife Sanctuary (SLWLS), threatens to destroy the habitat of the bird.

 "Endemic to a country where some 13 per cent of the world’s birds have been recorded, the Jerdon’s Courser clings to existence in a tiny habitat of scrub forest threatened by livestock grazing, quarrying, and canal-building"

 says P. Jeganathan and Dr. Asad Rahmani

Read the full article at http://www.sanctuaryasia.com/features/detailfeatures.php?id=779

 

Bio-Diversity

A afternnon activities of Birds

Posted by aditya on May 14, 2006

 
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As every bird watcher knows morning time is best time for bird watching or evening time. But any time have You tried What are the activities at afternoon?

Yesterday I went with my friend Dr. Pramod Bansode[ One of the best bird watchers and Wildlife photographers] to see the afternoon activities.  The tremendous heat and initially no activity, which make us feel bored. But since we had expected it, we waited with patience. and as we know "Sabra ka phal Mitha hoto Hai!" .After Locating one small pond with water which was surrounded by many trees, we took our positions and started observing the birds. In starting there are 2 pairs of Red whiskerd bulbuls  in the water and their water play was going on and suddenly 6 jungle babblers arrived and started playing in water along with them; 1 pair of Magpie Robins and pair of Common indian Mynahs joined the water party. A wonderful play of all these birds we were watching on that day. There are other party animals too look Brahminy Skink, Rat snake and One  Common Indian Mangoose. For actual Detail report of this Article mail on

 adi_sawant@rediffmail.com  

adi_sawant10@yahoo.com

 

Bio-Diversity

Existence of Forstein's Cat Snake (Boiga forsteini)in Central India

Posted by Susan Sharma on May 10, 2006

 
Forum Post

Hi Harshad,

 I found this message in yahoo group "Naturepix" which will interest you.

jugal tiwari jugalt2000@yahoo.com wrote: Mount Abu in India is a great place for Reptiles. Atleast 16 species of Snakes are here (I have in my photo collection). The great work of Reptile rescue is being done by Kiran Chavda, Shailesh patel and the team. This forsten's cat snake is a rarity in Mount Abu. There are only 4-5 rescues from residential areas in 18 years time. They live in pairs, this one was rescued by Shailesh patel from the St. Mary School building. Jugal Tiwari 09414026156

Message from Yahoo group Naturepix message No. 6606

You can read the message at

http://groups.yahoo.com/group/naturepix/messages/6602?viscount=-100

 

Bio-Diversity

gekos at peb fort- matheran

Posted by aditya on May 06, 2006

 
Forum Post

Peb fort near Matheran is a treat for bird watcher and herpetologist. I  visited  this fort  last Sunday. It was a very harsh treck due to summer heat. On peb fort there were many caves some of them are natural and some of them are man made. in these caves there were many gekos such as

1]Rock geko : Hemidactlylus maculatus.

 2]Ground geko: Gekoella sp.

3] Bark geko:hemidactlyus leschenaltii. 

We also get some snake Species such as

1] rat snake

2] Indian krait: in cave

3] Indian cobra:

At the base of fort a lot of bird species listed there. I watched 42 species in single treck. special achievement of treck is locating two nests of crested serpent eagle. it was an amazing treck. for more details e mail me on adi_sawant@rediffmail.com

 

Bio-Diversity

Existence of Forstein's Cat Snake (Boiga forsteini)in Central India

Posted by Harshad V Kulkarni on May 04, 2006

 
Forum Post

One of the beautiful Indian snakes is Forstein's Cat snake. According to the reference in The Book of Indian Reptiles & Amphibians by J.C.Danial(BNHS),this snake is found in forests of western ghats and in Assam.

But last year we found two females of these species with one male too. The sizes were 4'9" ,4'8" and 5'2" respectively.

 I hope that this will be a great finding.

Bio-Diversity

Bio Diversity of Uttaranchal

Posted by Susan Sharma on March 01, 2006

 
Forum Post

The renowned biologist A.J.T Johnsingh suggests that the forests of Uttaranchal can easily support about 1000 elephants and 200 tigers as long as this large habitat, now fragmented in three blocks is managed and protected as one continuous habitat for wildlife.

We have uploaded his report " A Road Map for Conservation in Uttaranchal" at the following link

http://www.indianwildlifeclub.com/ResearchPapers/Conservation-Uttaranchal.pdf

Since this is a pdf file, downloading will take some time. But I can assure you it is well worth the wait. Mr. Johnsingh is an academic who is well versed with grassroot level realities and I have heard him passionately pleading the cause of conservation - repeatedly stressing the need for field level awareness before taking up conservation issues.

Bio-Diversity

National Bio-Diversity Action Plan

Posted by Susan Sharma on November 25, 2005

 
Forum Post

"It is a much-ignored reality that tens of millions of people in India still survive on the biodiversity of forests, seas, wetlands, grasslands, mountains and coasts. The true value of these ecosystems and the species of plants and animals they contain is not reflected anywhere in parameters of development like Gross National Product."

 It is unfortunate that the National Bio-Diversity Action Plan drawn up by the Ministry of Environment and Forests with the assistance of Kalpavriksh, an NGO and Biotech Consortium India Ltd,  is creating controversies and delaying the much needed action.

 

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