The 'Fish Out of Water' Blog

written by Tom Edathikunnel

Month: September, 2014

American Museum of Natural History Unveils Iconic Galapagos Tortoise ‘Lonesome George’ on Exhibit

1). Lonesome George_AlizonLlerena(CDF)

The Museum of Natural History unveiled its latest specimen this week, showcasing Lonesome George, the final member of the now extinct species of Pinta Island tortoise. Set amid the spectacular fossils in the museum’s Hall of Primitive Mammals, this tortoise stands as a challenging reminder of the fragility of life and present need for conservation. As the last of his species, Lonesome George maintains his hold of deep wonder, demonstrating the immediate environmental impacts of human indifference and ignorance.

Weighing 165 pounds, measuring 5 feet long, and living for over 200 years, Lonesome George (Chelonoidis abingdoni) offered scientists a unique look at a species long thought extinct. In the early 1900’s this species of giant Galapagos tortoises were thought to have vanished due to centuries of over hunting for meat and oil. However George was a surprise discovery, stumbled upon by a Hungarian scientist in 1971.

10a). Lonesome George on view_RM_140916_0975-2

George on display

The larger symbolic nature of George continues to ripple outward, motivating naturalists and conservations across the planet. The Galapagos islands are interesting in there isolation, leading to a myriad of species which have evolved a wide variety of adaptations. These islands were once home to more than 200,000 tortoises comprising of 14 different species. Of these vast numbers, four species have gone extinct in the last 200 years.

This rapid destruction is large in part due to the over hunting of man and the introduction of foreign species to this isolated ecosystem. With reflection and a deeper understanding of the relationship of flora and fauna, humanity can take the practical steps toward sustainable development, balancing the need to grow with a responsible allocation of resources.

Now preserved by Wildlife Preservation taxidermy expert George Dante, Lonesome George is now on display in impressive detail- from the missing toenail on his left foot to the grass stains on his neck. With this enormous effort to life like preservation and reconstruction, this individual will be a engaging display for Museum guests until January 4th, 2015.

 

Images courtesy of The Museum of Natural History.

 

New Data Sheds Light on the Evolution of Terrestrial Life

bichir-walking

The breach of aquatic life to terrestrial forms is arguably one of the most interesting and puzzling evolutionary breakthroughs. This pioneering biology marks a distinct transition in the evolution of life on Earth, marking a wider variety of required anatomy and adaptations for fitness. The first organisms to cross this threshold were photosynthetic plants in the Ordovician period 450 million years ago followed by the first vertebrates in the Paleozoic Era.

These early tetrapod pioneers were undoubtedly amphibian in nature, requiring a close proximity to water for a majority of biological functions. However the mechanics of this development have been unclear. In a new experiment lead by Emily Standen of the University of Ottawa Canada, her team took juvenile bichir (Polypterus senegalus), a small freshwater fish native to the Nile River of tropical Africa, and raised them on land.

bichir
Bichirs, a species of ray-finned fishes (left), posses paired lungs connected to their esophagus. This rudimentary vascular system, along with their gills, allows these unique fish to live both on land and in water.

After eight months of terrestrially life, the bichir demonstrated a more sophisticated style of walking than did their aquatically raised counterparts. They displayed adaptations on a skeletal level, having musculature suited better for a walking lifestyle.

The results of this interesting experiment demonstrate the plasticity of evolutionary development, which allows organisms to alter their anatomy and behavior to respond to environmental changes. Emilty Standen and her team suggest that this process could have provided early tetrapods the ability to live on land. Selective pressures gave rise to the propensity of rudimentary lungs from gills, limbs from fins, and other anatomical necessities for terrestrial life.

Thus environmental conditions remain the driving force for selection, forcing dramatic and creative solutions for survival. This process works subtly, requiring millions of years and beyond. The bichir are just one example of the life branching to new territories and gaining new abilities to adapt and excel.

 

 

Source: “How Fish Can Learn to Walk,” Noah Baker, nature.2014.15778