Researchers, physicians, and others have investigated the dark crevices of the gene, trying to untangle clues that might indicate that gene function could be altered by more...
RefugiaLast Updated on 2013-10-21 15:07:19
Refugia (singular Refugium) are geographical locations where natural environmental conditions have remained relatively constant or stable during times of great environmental change, such as eras of glacial advance and retreat. Refugia protect populations of geographically isolated organisms which may then re-colonize a region when the wider environment returns to levels within the organism's tolerance levels. This idea is commonly referred to as The Refugia Theory.
Haffer (1969) first proposed the idea of refugia to explain the high diversity of Amazonian bird species seen today. Haffer (1969) proposed that the Amazon Basin paleoclimate experienced several warm, dry periods during episodes of continental glacier advance in the Pleistocene. These glacially driven periods led to the conversion of forest to savanna, which resulted in the isolation of small fragments of forest... More »
Contemporary evolutionLast Updated on 2013-07-18 16:32:36
Rapid environmental change, whether human induced such as fishing and hunting pressures, toxic chemicals, or natural climatic changes resulting in altered food availability have provided opportunities to observe rapid microevolutionary changes in contemporary time, or contemporary evolution. These are population level changes which tend to occur over a few centuries or much less time (depending on the species) and may be observed after only a relatively small number of generation cycles depending on the species. Well known examples of contemporary evolution include pesticide and antibiotic resistance. Yet we now know that animals other than pest species can evolve in response to rapid environmental change (including chemical expsoures).
However distinguishing rapid, adaptive genetic change from phenotypic plasticity (altered phenotypic expression of a single... More »
Species range limitsLast Updated on 2012-08-15 00:00:00
Species range limits (SRLs) are defined as the spatial boundaries beyond which no living individuals of a given species occur. Populations occurring near or at SRLs are often referred to as “marginal,” “peripheral,” “edge,” or “border” populations. SRLs may represent areas beyond which individuals cannot physiologically tolerate ecological conditions or areas where they have not yet dispersed. SRLs may be stable (i.e., at equilibrium) or may represent areas where range expansion through migration or population growth is in the process of occurring. SRLs are significant to ecology, evolution, and conservation for several reasons. They provide opportunities to understand the conditions under which populations expand or contract, and the conditions under which populations may evolve new forms. Additionally,... More »
Regeneration of Ice Age seedsLast Updated on 2012-02-21 00:00:00
Regeneration of Ice Age seeds has become a reality, with dormant seed bank material dating older than 30,000 years before present having been brought to life by Russian scientists. Seeds of the wildflower plant Narrow-leafed campion (Silene stenophylla) were recovered in the Kolyma region of Siberia and induced to produce viable living plants. This flowering forb exhibits a pale lilac flower and attains a stature of approximately seven to 24 centimeters in height.
Apparently the S.stenophylla seeds were gathered by the Arctic ground squirrel (Spermophilus parryii), a seed gatherer who burrows in the tundra and hibernates over the winter. This ground squirrel characteristically takes seeds to its winter burrow, and descends into the coldest mammalian body temperature realized of approximately minus three degrees Celsius.
Even though the plant species Narrow-leafed campion is... More »
Ashmore and Cartier IslandsLast Updated on 2011-12-01 00:00:00
Ashmore and Cartier Islands are uninhabited and protected islands and reefs in the Indian Ocean, midway between northwestern Australia and Timor island.
Ashmore Reef 155.40 km2 (60 sq mi) area within reef (including lagoon)
West Islet, 51,200 m² land area;
Middle Islet, 21,200 m² land area;
East Islet, 25,000 m² land area;
Cartier Reef (44.03 km² area within reef (including lagoon)
Cartier Island, 17,000 m² land area;
The Hiberian Reef, also part of Australia, is near by.
The major environmental issues include: illegal killing of protected wildlife by traditional Indonesian fisherman, as well as overfishing by non-traditional Indonesian vessels, are ongoing problems . Islands are susceptible to... More »
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