Wednesday, December 11, 2013

Research sheds light onto the debut of insect life on Earth

LAWRENCE — “Insects dominate our world,” according to University of Kansas researcher Michael Engel. Thus, anything scientists can learn about the evolution of insects leads to a better grasp of how biology in general has changed over time.

“More than half of all known species on the planet are insects, and they rule virtually all terrestrial and freshwater ecosystems,” said Engel, a professor of ecology and evolutionary biology. “Many insect lineages are ecologically ubiquitous — such as bees, ants, termites — and they impact our daily lives in a big way. They pollinate our crops; they are the sources of many of our medicines or other chemicals; and some are tied to the spread of disease.”

Understanding the factors that led to insect origins and fueled their successes, as well as what pushed particular groups to extinction, such as the influence of climate change, is vital to human health and security.
Engel has just co-authored a paper in the prestigious journal Nature that sheds new light on the evolution of the Eumetabola, a scientific term for the group of organisms that includes most insect species.
“Beetles, bees, ants, wasps, flies, butterflies, moths, fleas, lacewings, lice, thrips, aphids, true bugs and all of their close relatives are eumetabolous insects,” said Engel. “If you are talking about insects, then you are likely talking about a eumetabolan insect.”

The researcher, who also serves as a senior curator at KU’s Biodiversity Institute, said that in spite of the importance of this group of insects, their earliest origins have been difficult to pin down.
“There’s been a lack of identifiable fossils from the Carboniferous Period or earlier deposits,” Engel said. “Until now, the first definitive specimens assignable to the Holometabola, the big chunk of the already massive Eumetabola, were from the early Permian — but those aren’t the most primitive of their kind, except in a few cases, and pointed to much earlier diversification events. From the Carboniferous, the immediately preceding time period, we only had specimens of much more primitive insect lineages. “

The size of the fossils makes them difficult to detect, according to Engel.

“They’re tiny, so unless you are hunting for them, they would be easy to overlook,” he said. “Also, fossils from these deposits aren’t preserved with a strong contrast between them and the surrounding rock. Thus, it takes specialized lighting to get them to easily pop out.”

Nevertheless, Engel and his co-authors in Nature describe newly discovered specimens and fragments that can be confidently tied to holometabolan lineages. More significant, the specimens are not of the typical orders but are far more primitive.

“For example, there’s a species related to the lineage that eventually would give rise to the wasps in Triassic,” he said. “It wasn’t a wasp itself and instead would look more like some kind of generalized primitive group, but it already had a few of the evolutionary novelties that would later be part of the order of wasps, ants and bees.”
Among the other five species Engel and his colleagues describe in Nature, one is an early relative of true bugs and their relatives; one is an early relative of barklice, and then ultimately true lice; and one is an early relative of the lineage that would give rise to the beetles in the Permian.

KU is a leader in paleontology generally, and Engel’s lab is one of a few worldwide with expertise in the fossil record of insects — and, among those labs, an even smaller subset have sufficient expertise in the Paleozoic.

Engel said an understanding of ancient development and origins of insects is vital for an understanding of our modern world.

“Our own evolution — biotic and cultural — is inextricably woven into the lives of insects,” he said. “Insects have been on the planet for at least 410 million years and were first to fly, first to develop agriculture and first to form complex societies. We like to talk about the ‘Age of Dinosaurs’ or the ‘Age of Mammals,’ but all of these are greatly dwarfed by an overarching ‘Age of Insects.’ If humans vanished from the Earth it would have only a beneficial effect on the greater biota. If insects disappeared, then life itself would struggle to persist.”

Original Story

Sunday, December 8, 2013

Sri Lanka on world map of biodiversity hotspots

Sri Lanka  on world map of  biodiversity hotspots
Sri Lanka is the home for a rich biodiversity, which is a part of its natural wealth. The country has a high endemism - 30% of its vertebrate animals and 28% of its flowering plants are found only in Sri Lanka. This diversity and the multiple threats faced included the country’s southwestern region among the ‘biodiversity hotspots’ designated about two and half decades ago.

Biodiversity hotspot concept emerged as an effort to identify conservation priorities and it was to define the areas that are the most immediately important for conserving biodiversity. The hotspots are locations that hold especially high numbers of endemic species, in a limited area of occupation which was under imminent threat.This concept was somewhat widely discussed in the conservation arena of the country and was used for decision making and policy issues related to biodiversity. 
A recent global study has pinpointed a list of most important protected areas specially for the conservation of bird, amphibian and mammal diversity. This is a result of the work of an international team, whose study was published in the world renowned journal Science few weeks ago. The most important issue is the fact that two Sri Lankan sites are among these ‘irreplaceable protected areas’.

New study

There is no doubt about the significance of protected areas for the conservation of biodiversity and conservation action which are centered on these at present. However, some of these protected areas may be highly important in terms when we consider the threatened biodiversity they harbor. This new study is an effort to identify such protected areas.  
‘Irreplaceable protected areas’ – the protected areas the researchers mention are defined as the protected areas most critical to prevent extinctions of the world’s mammals, birds and amphibians.Through their analysis, the researchers identified 137 protected areas situated in 34 countries, as “exceptionally irreplaceable”. These sites are the home for about 627 birds, amphibians, and mammals, and 319 of them are listed as globally threatened. More than half of the distribution of these animals is confined to these protected areas.This shows that the importance of these protected areas in terms of conserving these taxa of animals, but they have also calculated the overall irreplaceability based on the all species available in these protected areas.
These are being calculated comparing each protected area’s contribution for the survival of the species. Extensive data available for 173,461 terrestrial protected areas in the world and assessments of 21,419 species on The IUCN Red List of Threatened Species have been used for this analysis.

Protected areas

According to the list of the identified protected areas, Sri Lanka has two sites, namely the Central Highlands World Heritage Site and Kanneliya Forest Reserve. These areas are well known protected areas in Sri Lanka in terms of their biodiversity as well as endemism. 
Central highlands complex is a world Heritage Site designated in 2010 and consists of three main protected areas – the Peak Wilderness Protected Area, the Horton Plains National Park and the Knuckles Conservation Forest.These forests include the largest and least disturbed remaining areas of the submontane and montane rain forests of Sri Lanka and these protected areas cover an area of 537 square kilometers. More than half of the country’s endemic vertebrates, half of the country’s endemic flowering plants are found in these forests and grassland ecosystems.However, these protected areas are threatened with anthropogenic causes. For instance, the Knuckles area is highly threatened with cardamom cultivation and the Peak Wilderness is threatened with encroachments.
Kanneliya forest reserve is located in Galle District in the southwestern region of the country. Kanneliya Forest is a part of the Kanneliya-Dediyagala-Nakiyadeniya International Biosphere Reserve under the Man and Biosphere Program of UNESCO in 2004.With a 62 square kilometer area, it is mentioned as the most extensive surviving block of low land rainforest next to Sinharaja forest. However the highest percentage of endemic woody species of any wet zone forest in the country (i.e. 60%) is recorded from Kanneliya. It is rich in faunal species too.

Clear message

The key message issued by this study is clear. These identified protected areas must be considered as crucial in conservation of biodiversity as they harbour a considerable high number of endemics and threatened animals – birds, amphibians and mammals as well as other species.Hence conserving those should be a high priority in those countries.
Dr. Ana Rodrigues, one of the authors of the above research paper pointed outin an email conversation that their main aim is to raise the profile of these exceptional sites, to improve their conservation prospects. This analysis provides practical advice for improving the effectiveness of protected areas in conserving global biodiversity. There are numerous challenges in the conservation of these protected areas, despite decades of conservation efforts worldwide.As we know, conservation itself is a struggle in the socio-economic context in the world, particularly in developing countries.
This research or its relevancy to Sri Lanka was not much highlighted in Sri Lankan media. This issue should be taken in to consideration of conservation authorities, when designing conservation strategies and action as the importance of these protected areas has been defined scientifically.
Pics by Bushana Kalhara

Friday, December 6, 2013

Tarantulas Loved to Extinction?

6 December 2013 6:15 pm
Spiders may not be the most cuddly of species, but some are so prized by collectors that their existence could be in peril. The pet trade is one of the reasons that the U.S. Fish and Wildlife Service (FWS) this week took a step toward putting 11 species of tarantula on its list of endangered species. This slideshow highlights some of these colorful species and their natural history.
The spiders live in India and Sri Lanka, so the main impact of listing them would be to generally prohibit their importation or sale within the United States. Most of the species live in trees and are threatened by deforestation. Some will enter homes, where people kill them. All of them are threatened by collection for the pet trade. The reddish parachute spider (Poecilotheria rufilata), in particular, is difficult to breed in captivity, and requires wild individuals.
Brent Hendrixson, a spider biologist at Millsaps College in Jackson, says that habitat destruction is most likely the largest threat to the tarantulas. “It might be a stretch to say that overcollecting is driving the numbers down,” he says. “We don’t have any concrete data on exports from India or Sri Lanka in terms of wild-caught animals.” Most of the individuals in the United States have been propagated through captive breeding programs, he adds. The peacock tarantula (Poecilotheria metallica), in particular, is well suited because it is easy to breed and grows rapidly. They’re also stunningly beautiful.
In 2010, a group called WildEarth Guardians in Santa Fe petitioned FWS to list species of the genus Poecilotheria and on Tuesday, the agency agreed that there’s enough science to warrant further review. That is supposed to take a year, but often stretches out longer. FWS willaccept public comments until 3 February.

Søren Rafn
The peacock tarantula (Poecilotheria metallica) is known only from a small forest reserve in Andhra Pradesh, India. Like others in the genus, they make funnel webs inside deep crevices of old growth trees.

BayLee's 8 Legged Art
The beautiful parachute spider (Poecilotheria formosa) lives in the Eastern Ghats in southern India and is poorly known. Males have never been discovered.

BayLee's 8 Legged Art
The reddish parachute spider (Poecilotheria rufilata) ambushes prey and has been seen capturing young bats. They are smuggled from India into Europe and America for the pet trade.

Found in the Kitulgala Forest Reserve of southern Sri Lanka, the fringed ornamental (Poecilotheria ornata) inflicts a painful bite. Like other tarantulas, its venom is not fatal to humans.

Brent Moore
The striated parachute spider (Poecilotheria striata) is popular among pet traders and collectors. It’s found across 2000 km2 of the Western Ghats in India, where its habitat continues to decline.

B. Smith
The wonderful parachute spider (Poecilotheria miranda) gets its name because males will sail down from trees to the ground. The population, in the Chhota Nagpur region of northeast India, is thought to be decreasing.

Laurence Livermore
The brown parachute spider (Poecilotheria subfusca) comes from south-central Sri Lanka. Scientists surveying their habitat from 2003 to 2005 found only 20 individuals.

Zoological Survey of India
The Rameshwaram parachute spider (Poecilotheria hanumavilasumica) was discovered in 2004 in a sacred grove on Rameshwaram Island in southern India. They ambush insects.