The 'Fish Out of Water' Blog

written by Tom Edathikunnel

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

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

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.

Latest Fossil Evidence Suggests a Feathered Dinosaur Ancestry

Illustration by Andrey Atuchin & National Geographic

Illustration by Andrey Atuchin

 

The wondrous images of dinosaurs roaming a prehistoric Earth are quickly reforming as new evidence of their appearance and uniquely evolved specialties are discovered. One of the latest and most interesting developments is the evidence that a number of dinosaur species possessed a variety of feathers.

While some species are known to have had feathers, these were thought to be a small niche group, separate from other species. Over the past decade, fossil findings from China have produced five different species of feather dinosaurs all from the theropod “raptor” group, the ancestors of modern day birds.

dinosaurs and birdsNow new discoveries from an international team in Siberia have unearthed a 4.5 foot (1.5 meter) two-legged ornithischian beaked dinosaur with feathers, the first to belong from a separate and distinct ancestrally linage than theropod dinosaurs.

This finding leads contemporary paleontologist to believe that the older common ancestor to all dinosaur species may too have possessed feathers. Feathers may not have been a characteristic of an evolutionary isolated species but rather a trait maintained by a larger majority of dinosaurs, similar to mammals possessing a wide variety of hair.

The fossil findings, which included six skulls and a number of bones, broaden the number of dinosaur families with feathers. This more detailed examination indicates that plumes of downy, ribboned, and thin feathers evolved from the scales that covered earlier reptiles. The Siberian ornithischian, named Kulindadromeus zabaikalicus, also possessed scales, most notably arched rows on its long tail.

This finding adds an entirely new perception to the evolution of both feathered dinosaurs and modern avian species. The scales on Kulinadromeus resemble the scaly skin on some modern birds, suggesting that a deeper genetic root links ancient dinosaurs to their modern ancestors. However this does not exclude the possibility that feathers are convergent evolutionary traits, which are similar features that appear in species of different lineages, such as bats, insects, and birds having flight.

 

Sources:
An Early Cretaceous heterodontosaurid dinosaur with filamentous integumentary structures. Zheng XT1, You HL, Xu X, Dong ZM: Nature. 2009 Mar 19.

 

Project MAVEN Sheds New Light on Martian Atmosphere

MavenProbe_m_1002

The latest data regarding Mars over the last several years has transformed speculation into identifiable atmospheric findings. Previous missions to Mars have shown scientists that the atmosphere of the red planet has changed drastically over time and have found evidence of the former abundance of liquid water on its surface. These exciting findings raise new questions. Where did the Marian atmosphere go and what happened to its water? NASA’s latest mission aims to find out.

The Mars Atmosphere and Volatile Evolution, or MAVEN mission is a satellite mission that will orbit Mars and investigate how the sun interacts with its atmosphere. The satellite aims to explore how the sun may have stripped the Martian atmosphere, turning the possibly lush and habitable plant into the cold and barren desert we see today. MAVEN is the first spacecraft dedicated to exploring the Martian atmosphere.

Following an elliptical orbit, this unique spacecraft will graze the atmosphere at 93 miles above the planet’s surface. At this altitude, the spacecraft will pass through the upper atmosphere and will be able to sample gas and other ionic compositions directly. The MAVEN will carry three instrument suites to analyze and observe the Martian atmosphere. The main payload consists of the Particles and Fields Package (PFP), containing six instruments that characterize solar wind and the ionosphere of the planet. Other instruments will measure the composition and isotopes.Its highest point will be more than 3,728 miles above the surface, allowing the MAVEN to map the entire planet in rich ultraviolet imaging.

This fusion of both these long and short-range instruments give this mission an unparalleled vision of the red planet, and give a scientists a clear and better defined profile of the Martian atmosphere. With more research and further findings, the incessant question of the evaporated Martian atmosphere, as well as the question of its hospitality for life, may finally be answered.

Modern Hearts Discovered In Ancient Shrimp

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A recent discovery from an international research team across the United States, China, and the United Kingdom has unearthed fossils of the earliest known cardiovascular system, a system that for the first time clearly shows a complex system of heart and interconnecting blood vessels. The primitive system, discovered in the Fuxinanhula protensa, is dated to be over half a billion years old. These findings shed new light on the evolution of body organization throughout the animal kingdom and show that early creatures possesses organ systems and complex organ interaction similar to those in modern decedents.

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The three inch fossil appears to be a shrimp like creature and was found entombed in fine dust-like particle during the Cambrian Period over 520 million years ago. Found in what is today the Yunnan province of China, researchers believe that this species is an extinct lineage of arthropods that took the first steps toward advanced internal anatomy.

Nicholas Strausfeld, a Regents Professor of Neuroscience at the University of Arizona’s Department of Neuroscience stated “this is the first preserved vascular system that we know of.” As one of the world’s most foremost experts in arthropod morphology and neuroanatomy Strausfeld, the creatures complex organ system is a pattern that appears very much like a modern crustacean.

71240_webIn a surprising finding, Strauseld pointed out that Fuxinanhula protensa, vascular system is actually more complex than what is found in many modern crustaceans. “It appears to be the ground pattern for which others have evolved,” he states. “Different groups of crustaceans have vascular systems that have evolved into a variety of arrangements by all refer back to what we can see in Fuxinanhula protensa. Over the course of evolution certain segments of the animals body became specialized for certain things, while others because less elaborate.”

This spectacular finding demonstrates the rich complexity of early life on Earth and the evidence of consistent shifts in adaptable traits and beneficial attributes. Evolution is neither linear nor progressive, in that traits do not move from simple to more complex. Only through their subsequent success for reproduction do they continue to propagate. Thus a complex vascular system may have been beneficial in Cambrian Earth 520 million years ago, but became less effective over time, resulting in the more simplified and specialized crustaceans we see today.

The article “An exceptionally preserved arthropod cardiovascular system from the early Cambrian” appears in Nature Communications, published on April 7th, 2014.

Life on Earth

Part II: Survival of the Fittest

Surival of the Fittest

The term survival of the fittest is used by both evolutionist and skeptics, often without a complete scope of its context and application. The term is not a measure of traditional physical fitness or even a measure progress; in fact the idea of linear path in evolution goes against the very nature of the theory. Fitness in the evolutionary frame can be deconstructed to a simple principle: Those who reproduce are those who survive.

Now this principle may seem obvious but it ties back to the core component of evolution, which is that those who are the most adept at reproducing in an environment, better known as the “fittest”, are those who leave more descendants.

Fitness is not measured by strength, intelligence, or speed, and while these are contributing factors, they are merely a result of the process. Survival is dependent on the adaptability to ones environment and the ability to reproduce within it; hence, the natural selection of a species’ lineage.

Logic of Natural SelectionAn organism capable of reproducing is the species that is evolutionarily going to excel and perpetuate. Speed for catching prey can be an advantageous trait that aids in the reproduction of one’s genetic material, (by catching more food more of that predator can survive, grow, and reproduce), however when that trait no longer yields a reproductive benefit, it ceases to be “fit”.

Examine this conception of fitness in the broadest sense possible. All animals on earth utilize oxygen and the main biological component for respiration. But the Earth’s atmosphere at one point contained mostly carbon dioxide, meaning that organisms that used oxygen for metabolic function would cease to be “fit”.

The great Oxygenation Event, is a time in Earths geological past that makes the sudden introduction and retention of oxygen in earth’s atmosphere. Taking place approximately 2.4 billion years ago, organisms that relied on higher levels of carbon dioxide to survive began to go extinct, unable to reproduce to the changing atmosphere.

Organisms that thrived in an atmosphere of greater oxygen content began to leave more decedents, and ultimately perpetuated the diversity of animal life we see today.

More specific influences can be seen in modern evolutionary trends and breeding techniques. As previously mentioned, fitness is the success of reproduction, and with complex creatures, mating and sexual expression play a larger role. Species with sexual reproduction have the largest diversity in form, which can be contributed to sexual selection.

For example, males in large mammals and birds often have ostentatious traits, whether that is colorful feathers, full manes, large antlers, long necks, horns, etc. These may not be functionally efficient- colorful plumage is taxing process to maintain and can make birds more obvious to predators – but it is advantageous or “fit” for sexual reproduction. Meaning that while large antlers can be physically cumbersome they are effective for thwarting other males and is a necessity to reproduce.

Thus, survival of the fittest is a dynamic idea, not limited to a particular attribute or skill. Through environmental challenges and reproductive success, the animals and plants around us continue to change and evolve. As conditions change, so too do the traits that make us “fit”.

Life on Earth

Part I: Ambiogenesis
Orgins of Life

In recent weeks I have been thoroughly interested in the formation of life on planet Earth. Researching the wide variety of theories I was genuinely open minded, even looking at creationist arguments for a divine supernatural creator. These arguments lead me to discover the cornerstone in the creationist argument against evolution, which is, that life cannot appear from non-life. Thus, something  had to exist to generate new life. This argument, however compelling you may find it, led me to research the evidence of spontaneously forming organic lifeforms. I soon discovered the compelling theory of abiogenesis, which is the natural process by which organic life arose from non-living matter.

The earliest life on Earth existed at least 3.5 billion years ago, during the Eoarchean Era when the molten crust of the Earth had just begun to solidify. The earliest specific evidence of life is biogenic graphite, which is just a composition of carbon molecules found in 3.7 billion year old metasedimentary rock. Additional evidence comes from microbial mat fossils found in 3.48 billion year old sandstone discovered in Western Australia.

img2Now the hypotheses for how life originated is fiercely divided into a number of categories. Many approach the idea with the simple question of how self-replicating molecules came into existence. If we begin with the assumption that life originated on Earth, (Many believe that life could have begun with microbial life entering Earth via meteoroids or comets. This hypothesis is called Panspermia, and is main reason why interplanetary probes are thoroughly sterilized.) the study conducted by Miller-Urey demonstrate that most amino acids can be synthesized in conditions similar to early Earth.  Several catalysts have been examined as well, including exposure to radiation and lightening.

Other theories, such as the “Metabolism First” hypothesis state that initial chemical reactions involved the spontaneous formation of simple molecules such as acetate, a two-carbon compounded formed from carbon dioxide and water. The underlying core of the theory is that life began by the accumulation of simple organic molecules in favorable conditions.

Symbiotic Fungi Have New Found Impact on Atmospheric Carbon Levels

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CHANTRELLE

Among the intricacies of the food chain, decomposers are often overlooked and ignored. These organisms, specifically those of the fungi kingdom, are critical to the recycling and redistribution of nutrients throughout an ecosystem. New research has added a deeper and more apparent level of importance to these eukaryotic organisms, linking many microscopic root dwelling fungi to the storage and release of carbon from the soil into the atmosphere.

According to a new research published by the University of Texas at Austin, the role of fungi on the global climate is currently vastly unaccounted for. Some types of symbiotic fungi, those that operate in cooperation with an ecosystems flora, can lead up to 70 percent more carbon stored in the soil.

“Natural fluxes of carbon between the land and atmosphere are enormous and play a crucial role in regulating the concentration of carbon dioxide in the atmosphere and, in turn, the Earth’s climate”, states Colin Averil, lead author on the study at the College of Natural Science at UT Austin.

Nitrogen Cycle

The data regarding the role of fungi demands a refocused look on how atmospheric greenhouse gases exert changes in soil and ecosystems. Soil contains more carbon than both the atmosphere and vegetation combined, which means that studying future climates depends on the in-depth understanding of how carbon cycles through land and air.

Plants utilize carbon, in the form of carbon dioxide, during photosynthesis. When the plan dies it adds additional carbon to the soil.  As fungi and other eukaryotes decompose it, its carbon is released back into the atmosphere. Fungi also play a pivotal role in the recycling of nitrogen. Most plants have a symbiotic relationship with root dwelling fungi, which help extract nitrogen and nutrients from the soil and make that nitrogen available in the soil for plants to absorb.

The new importance of fungi in the natural order of ecosystems highlights the vastly complex flow of energy throughout an environment. With so many variables and factors filtering and distributing resources, it becomes more apparent that humanity still remains vastly ignorant of how specific parts and species contribute to the whole.