The 'Fish Out of Water' Blog

written by Tom Edathikunnel

Category: Science

The Quaternary Extinction & The Evolution of Modern Mammals

Ice Age MegaFauna

Ice Age MegaFauna

As concern continues to grow over climate change and the rapidly altering ecosystems around the globe, examining the past provides unique insight into the cyclical patterns of nature. Massive extinctions and catastrophic changes in climate have been the catalyst for a number of massive ecological changes. Massive epoch ending extinctions pave the way for new organisms to evolve and create a new environment for adaptation to thrive.

The most recent and mysterious is the Quaternary extinction event, which occurred 13,000 years ago. Also referred to as the Pleistocene extinction, this event saw the extinction of numerous megafauna species. Common megafauna (which consist of species over 100 pounds) included several species of wooly mammoth, giant hippos, saber-toothed tigers, and a variety of other large mammals that were common throughout the North American continent.

The driving cause of the Pleistocene extinction remains largely unknown. Such a massive extinction of large animals points many to believe the cause was a cataclysmic event. Due to the multiple glacial advances and withdrawals many scientists believe this rapid change in the ice age may explain such massive extinctions. Massive melting and tumultuous climate conditions could have quickly altered vegetation, forcing these larger animals to starve or migrate.

The documented evidence of early human beings make this period unique compared to other ancient extinctions. Theories of human overhunting have emerged as a potential cause for the massive extinction of these megafauna but similar to the discussion of climate change in contemporary discussion, the impact of human interaction may be severely overstated.

As more research on the changing climate of Earth emerges through geology and paleoclimatology, the ancient events of Earth’s biological past begin to emerge. This notable epochs mark the distinct developmental branches and ushers in new environmental conditions that force evolutionary adaptations. Whether from hunting or catastrophic climate changes, the large megafauna of the Quaternary age were unable to adapt to the changing environmental conditions.

Sources:

“Was a hyperdisease responsible for the late Pleistocene megafaunal extinction?”  Kathleen Lyons, Felisa A. Smith, Peter Wagner, Ethan P. White, and James H. Brown. Ecology Letters, (2004)

Images:
“Ice age fauna of northern Spain” by  Mauricio Antón

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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.

 

NASA’s New Horizon Spacecraft Gives Earth the Latest View of Pluto

Pluto & Charon

Beyond the rocky planets of our inner solar system and the gaseous giants of its outer reaches, lies the Kuiper Belt, a massive and unexplored area of space littered with chunks of rock, metal, and frozen volatiles of methane, ammonia, and water. Within this mysterious area of space is Pluto, the dwarf planet which has been virtually invisible until now.

NASA’s New Horizon spacecraft is taking a magnificent new look at the Pluto system and is set to meet this dwarf planet and its moons in the summer of 2015. Equipped with the Long Range Reconnaissance Imager (LORRI), this onboard telescope has been capturing spectacular movies of Pluto and its largest moon Charon. The 12 images (above) that make of this ground breaking compilation were taken between July 19th – 24th, from a distance of 267 million miles (429 million kilometers). Charon, the largest of Pluto’s five moons, is approximately 1,207 kilometers in diameter and orbits at approximately 11,200 miles (18,000 kilometers) above the dwarf planet’s surface.

Pluto and Charon IIPluto’s other four satellites, Nix, Hydra, Styx, and Kerberos, are still too faint to be seen by New Horizon but will soon appear in images over the course of the next year as the craft approaches the Plutonian system.

These images mark the first look at the distant orbiting body, shedding new light on the virtually unknown entity. “The image sequence showing Charon revolving around Pluto set a record for close range imaging,” said New Horizon’s mission Principal Investigator Alan Stern to NASA. “We will smash that record again and again starting in January as approach operations begin.”

Distant encounter operations begin on January 4th, 2015 as New Horizon approaches Pluto. As the craft draws closer to the Kuiper Belt, scientist will get a new perspective on the history and chemical composition of our solar system as well as a deeper look onto this virtually unknown world.

 

Images:

New Horizons Spies Charon Orbiting Pluto” published on August 7, 2014 by John Hopkins Applied Physics Laboratory.