Sunday, May 1, 2016
Biodiversity is the variability found within a species, between species and the variability among ecosystems. It plays an irreplaceable role in our lives as we depend on biodiversity for many requirements including food, energy, medicine and other material. It also has a significant importance in the traditional culture, religion and social practices. Apart from the tangible and intangible resources that directly affects us biodiversity also provides priceless services as ecosystem services which are crucial to maintain the natural balances on earth. Therefore, maintaining the biodiversity in a natural state and allowing it to alter following the natural patterns is critical for the existence of all life in the biosphere.
However, in recent centuries humans have been altering the natural systems and endangering the biodiversity around them in a drastic manner resulting in a rapid loss of biodiversity. This has been intensified since the industrial revolution and many accepts that we are causing a mass extinction event. Currently biodiversity loss has been identified as one of the leading global environmental issues we are facing. Anthropogenic activities such as habitat loss and degradation, spread of invasive alien species, climate change, over exploitation and environmental pollution are the major drivers of the ongoing biodiversity loss.
Conservation biology is a crisis discipline that developed in recent decades as a response to this ongoing crisis of biodiversity loss with the aim of combating it. Conservation biologists are attempting to minimize the negative human impact on biodiversity and allowing the natural dynamics with a scientific approach. However, as anthropogenic causes are the main driving forces behind the ongoing biodiversity loss, the role of conservation biologists is becoming more challenging day by day.
Human population on earth has undergone a rapid expansion in the last centuries mainly with the recent development in health and agriculture. At the dawn of the 21st century the world population was around 6 billion but it reached 7.3 billion by 2015. Even though the rate of human population growth is declining at present, the magnitude of the current population is so significant that it is impacting on the earth in severe scales. Fulfilling the needs and wants of this huge population of one species is having a negative effect on many other species as well as ecosystems putting them on a knife-edge situation.
Many species are already facing a severe threat of extinction. The global and local red lists made and updated time to time are alerting the society including the conservation biologists on the species which are at the brink of extinction. However, conserving these species and minimizing their extinction risk is not easy as it has to be done in a way that does not interfere the human activities to an extent that would cause a negative reaction from the stakeholder communities. Therefore, conservation biologists have a challenge to maintain the social, economical and ecological balances in order to make conservation a reality.
Agricultural lands are expanding in certain areas to supply the food resource requirement of the human population and human settlements are similarly expanding. Altogether, with other human land-uses, these are consuming about 13 million hectares of natural forests annually and converting them to different land-uses. The expansion of human modified land-uses are pressing the wildlife to their survival and causing a conflict among humans and wildlife. In other areas, agriculture is becoming intensified using the novel agricultural practices and human settlements are becoming concentrated to urban areas generating higher pollution and causing a chain of negative effects on biodiversity. Over exploitation of biological resources, which is evident in many cases including the well known “fishing down the food web” are also throwing out the natural balance in ecosystems. Conservation biologists are facing the challenge of establishing a balance to these systems which is in favour of biodiversity but also fulfills the growing requirements of the human population in the 21st century.
Conservation is not an activity that can be achieved single-handedly. Conservation biologists require the support and commitment from various stakeholders to make a significant positive effect on the biodiversity. These stakeholders include local communities, government authorities, political movements, industries, funding agencies and many others. However, these stakeholders may not share the same objectives or views that the conservation biologists have. With their own agendas and targets, some of them are in a state of competition with the many competitors in a large population and some are trying to meet the demands of the growing population. This will be even more significant in developing countries where poverty and political unrest are common and widespread issues. Therefore, bringing these different minded stakeholders together and making a positive dialog between them is challenging for the conservation biologists and it requires many skills.
One thing we have to understand is that the world has already being changed drastically to meet the needs of the human population and the 21st century will not see any significant difference in this process. Understanding this, 21st century conservation biologists and the society must find ways to carry out their activities with a minimal effect on biodiversity thus the benefits of the biodiversity will be perpetual. In order to achieve this, novel methods must be identified and developed to attract and sustain biodiversity within human modified landscapes and incorporate them to the biodiversity conservation efforts. This is a challenging task for everyone including the conservation biologists as these methods will have to be applied for different situations and will require specific modifications for different cases. This also involves the challenge of overcoming the mental hurdle that would prevent us from seeing human-modified land-uses as different units from areas for conservation.
With the growing human populations, complex human life styles and novel needs of the 21st century humans, the conservation biologists and the society are in a very challenging position to minimise the loss of biodiversity and ensure its sustainability. Therefore, identifying these challenges and finding methods to overcome them are important in order to make conservation a reality.
Sunday, February 21, 2016
Among the billions of life forms around us, odonates or dragonflies and damselflies have been occupying only a small fraction of it with around 6,000 species currently known to science. The systematic study of odonates began with the birth of Linnaean taxonomy in 1758 and biologists and naturalists have been describing odonates around the world and assigning names for these species.
So, after the 257 years, where do we stand now?
Naming a species is the basic requirement in order to truly appreciate it and conserve it. Without giving a name to a species you can not study it, assess it for its conservation value or even discuss it. As odonates are wonderfully colourful, attractive, active, usually diurnal and comparatively large bodied insects, one might think that we already know enough of them after centuries of systematic studies and exploration.
However, questioning this view, 60 new species of odonates were described from the continent of Africa by a single paper authored by K. D. B. Dijkstra, J. Kippings and N. Mézière just at the end of 2015. If you think about the total number of odonates known from around the world, this has increased the number of species from around 1% single handedly. A very interesting fact regarding these discoveries is that all of them have been made in the field, not inside a lab while studying the molecules. And some of them were not made from remote jungles but from places no one has cared to look intentionally before.
The important point is, if that many African species were yet unknown to science until the last year, how many undescribed species might be there in the other regions? Especially, in the hottest biodiversity hotspots around the globe, including Madagascar, Indo-Burma, Sundaland, Philippines, Atlantic forests in Brazil and Western Ghats/Sri Lanka.
As a biologist working in Sri Lanka I am well aware that only seven new species and two new subspecies have been described from Sri Lanka since the year 2000. According to the odonata checklist published by K. A. Subramanian in 2014 and a recent paper by C. G. Kiran, S. Kalesh and K. Kunte, this number is only six species in the whole of India with only two in the Western Ghats.
So, are we done? No, not even close.
You can read the interesting facts about the new discoveries from Africa here.
Bedjanič, M., van der Poorten, N., Coniff, K. and Salamun, A. 2014. Dragonfly Fauna of Sri Lanka: distribution and biology with threat status of its endemics. Pensoft, Sofia. 321 pp.
Kiran, C.G., S. Kalesh & K. Kunte (2015). A new species of damselfly, Protosticta ponmudiensis (Odonata: Zygoptera: Platystictidae) from Ponmudi Hills in the Western Ghats of India. Journal of Threatened Taxa 7(5): 7146–7151;
Klaas-Douwe B. Dijkstra, Jens Kipping & Nicolas Mézière (2015). Sixty new dragonfly and damselfly species from Africa (Odonata). Odonatologica 44: 447-607.
Subramanian, K.A. (2014). A Checklist of Odonata of India. Zoological Survey of India, Kolkata.
Friday, August 15, 2014
Spiders are a divers group of organisms with many different forms and shapes. Among the World's spiders the most abundant group is the Family Salticidae of which the members are commonly referred to as "jumping spiders". Even the jumping spiders are very diverse in their morphology. All these are characterized with two large eyes on the front and a total of eight eyes. Most of the ant-mimicking spiders stands among these jumpers of the Salticidae. The most common of these are found in the Myrmarachne genera which is mainly distributed in the old world even though some members are found in the new world too. In both these regions usually they are more abundant in the tropics. Other than the jumping spiders, there are spiders that mimic ants belonging to other spider families too but usually they are not commonly referred to as ant-mimicking spiders.
The ant-mimicking spiders look similar to an ant in general body colour and shapes. Their cephalothorax appear as two distinct tagma mimicking the head and the thorax of an ant and the first pair of legs are kept lifted in to the air mimicking the antennas of the ants. In size also they are similar to the species of ant they are mimicking. The chelicerae of the ant-mimicking spider males are elongated than that of the females.
However some features makes the distinction of each group from the other easily. A close examination of the antenna looking appendages of the ant mimicking spiders will allow the observer to notice that they are connected to the thorax proving that they are actually legs, not antennas. In many cases that I have observed, the behaviour of these spiders are also different from the ants. It always allowed me to readily identify spiders among ants. Their movements are usually different and they can jump unlike most of the ants. And these spiders can hang from their silky threads, how many ants can achieve that? None.
The reason behind this mimicry is finding protection from the potential predators. As many animals do not prey upon ants due to the formic acid they produce the spiders also can achieve the same protection by mimicking the ants. In some species the spiders use the mimicry to hunt the ants they mimic or to prey upon the aphids that the ants tend to.
Thursday, December 6, 2012
He was born in 1928 at Purton, England. He finished his Bachelor’s at University of Birmingham and his Ph.D. at Oxford.
His studies were largely focused on behaviors of animals. He is a well known zoologist, ethologist (scientists who study animal behavior) and a sociobiologist.
Other than being an eminent biologist, he is a talented artist too. He has conducted many solo art exhibitions in Britain as well as other European countries.
He is un-doubtfully one of the greatest and most influential zoologists in all time.
He was born in Alabama, United States on 1929. He completed his Bachelor’s and Masters at University of Alabama and his Ph.D. at Harvard University. He later joined Harvard as an academic and became a professor in entomology for the Department of Organismic and Evolutionary Biology.
He is a biologist with expertise on many disciplines. He is the World’s leading authority in Myrmecology (Scientific study about ants) and he is also considered as the Father of Sociobiology. He is an eminent researcher and a talented author.
He was interested in insects from his childhood and developed a strong liking towards ants. He did many researches on their diversity, ecology and behaviors later in his life and published the book The Ants in 1990 with his colleague Bert Hölldobler. This work won the Pulitzer Prize for General non-fiction in 1991.
He studied the evolutionary mechanism behind social behaviors such as altruism and aggression and developed the concept sociobiology, the scientific or systematic study of the biological basis of all forms of social behavior through his book, Sociobiology: The New Synthesis published in 1975.
He has authored many more books during his life time. His work On Human Nature (1979) also won him a Pulitzer Prize for General Non-fiction. He wrote an autobiography titled Naturalist in 1994. One of his recently published books, The Superorganism: The Beauty, Elegance, and Strangeness of Insect Societies (2009) which was written by him and Bert Hölldobler is considered as one of the best books on the subject.
He has been awarded by many science and civilian awards throughout his life.
(1907-1964) Born in Pennsylvania, United States. She completed her masters in zoology in 1932 and later joined the U.S. Bureau of Fisheries as a junior aquatic biologist.
She eventually became a well known marine biologist and authored three best selling and well known books exploring the life in sea from the shore to the depths. Under the Sea Wind (1941), Sea Around Us (1951) and Edge of the Sea (1955) were those three books and by the time she completed this trilogy she was better known as a full-time nature writer.
Her most influential work, The Silent Spring was published in 1962. This book which was based on her research regarding the environmental and health impact of chemical pesticides including DDT gained a huge attention from various communities. It inspired many environmental movements in the United States which later formed the U.S. Environmental Protection Agency and also led to a national ban on DDT.
She died from a heart attack on 1964 and she was posthumously awarded the Presidential Medal of Freedom (highest civilian award in US) in 1980.
He was born in 1928 at New York. He did his bachelor’s in mathematics and physics at Amherst College and Ph.D. in biophysics at university of Yale. Later he joined the staff of University of Illinoise where he still works.
Though he is a physicist by training he has contributed a lot as a microbiologist. He described the Domain Archaea based on phylogenetic taxonomy of 16S ribosomal RNA and introduced the three domain classification in 1977.
His major publication is his 1967’s work The Genetic Code: the Molecular basis for Genetic Expression.
He was awarded by the Leeuwenhoek medal (the world’s highest award in microbiology. Awarded once in 10 years by Royal Netherlands Academy of Arts and Sciences) in 1992.