Thursday, March 25, 2010

586)Remarkable Creatures: For Extinct Monsters of the Deep, a Little Respect; Quotes From Blogpost Four Hundred

"...As we use our intellect to gain new knowledge about Creation, we come to see even more profoundly the depth and breadth of its mysteries. We explore unknown regions beneath the seas – and in outer space. We reach back over hundreds of millions of years in time. Extra-ordinary fossilised geological specimens seize our imagination – palm leaves, amethyst flowers, hedgehog quartz, sea lilies, chrysanthemum and a rich panoply of shells. Indeed, these wonders are found beneath the very soil on which we tread – in every corner of the world – and they connect us with far distant epochs and environments.
And the more we discover, the more we know, the more we penetrate just below the surface of our normal lives – the more our imagination staggers. Just think for example what might lie below the surfaces of celestial bodies all across the far flung reaches of our universe. What we feel, even as we learn, is an ever-renewed sense of wonder, indeed, a powerful sense of awe – and of Divine inspiration"(Aga Khan IV, Delegation of the Ismaili Imamat, Ottawa, Canada, December 6th 2008)For the full version of this quote see:

“Muslims believe in an all-encompassing unit of man and nature. To them there is no fundamental division between the spiritual and the material while the whole world, whether it be the earth, sea or air, or the living creatures that inhabit them, is an expression of God’s creation.”(Aga Khan IV, University of Virginia, Charlottesville, Virginia, USA, 13 April 1984)

March 22, 2010

For Extinct Monsters of the Deep, a Little Respect


Here is a quick paleontology quiz. Which group of animals included large, air-breathing predators up to 50 feet long that bore live young, dominated their world for more than 100 million years and were ultimately exterminated by an asteroid 65 million years ago?

Easy, right?

Did you say dinosaurs? Sorry, wrong answer. But it was a trickier question than it may have appeared.

The correct answer is marine reptiles, which at the time of the last great extinction included mosasaurs, plesiosaurs and pliosaurs. The key clue in my question was “bore live young.” Unlike the dinosaurs, which were terrestrial and laid eggs, marine reptiles were fully aquatic and bore live young. This latter combination was no coincidence.

Despite their awesome size and abundance in the fossil record — their bones were among the first to be recognized as fossil remains of extinct creatures — marine reptiles have long played second fiddle to their much more famous saurian cousins.

But if we humans were aquatic creatures, we would have a whole lot more respect for these other reptiles. They were the top predators of Cretaceous seas. Thanks to their prevalence, scientists have figured out a lot about them, particularly recently. This includes, most remarkably, insights into their genetics — something that is not even preserved in the fossil record — and what it took to transform ordinary lizards into extraordinary sea monsters.

The first scientific description of a fossil marine reptile was of a beast discovered in 1764 by workmen in an underground limestone quarry near Maastricht, in the Netherlands. It took a long time for the identity and significance of the bones to be realized. At first mistaken for a crocodile, fish or whale, the creature was pilfered by the French Army when it seized Maastricht in 1795. The fossil was eventually recognized as something entirely different and named Mosasaurus (“Mosa,” Latin for the Meuse River, near Maastricht, and “saurus,” meaning lizard).

Mosasaurs and other marine reptiles were center stage in the growth of the fossil record in the early 19th century. Ichthyosaurs and plesiosaurs like those discovered by young Mary Anning in the Lyme Regis area of Dorset, in southern England, were displayed in museums across Europe. Marine reptile fossils have been found across the globe, from Africa to Australia, and even Antarctica, a distribution that documents their long success. The first report of the creatures in the American West was from the Lewis and Clark expedition, which encountered a large skeleton in 1804 while voyaging up the Missouri River in Sioux country. It, too, was initially misidentified as a fish, even though at a reported 45 feet long, that would have been one heck of a fish.

Indeed, the name ichthyosaur means “fish lizard” and describes the streamlined body form that resembled large fish and sea mammals like dolphins.

Extinct marine reptiles also exhibited another important similarity to all sea mammals: they bore live young. We know this because among the plethora of fossil skeletons that have been unearthed are specimens of female ichthyosaurs, mosasaurs and other extinct marine reptiles preserved in the act of giving birth, with their young emerging tail-first, just as baby whales, dolphins and manatees do; doing so prevents the air-breathing young from drowning.

The bearing of live young distinguishes the marine reptiles from many other reptiles that lay eggs, like lizards and snakes, as well as dinosaurs. Even reptiles that spend most of their time in water, like crocodiles, sea turtles and marine iguanas, must come to land to lay eggs. This is because gas exchange through the eggshell is too slow underwater to allow the young to develop.

Interestingly, the only living reptiles that spend their entire lives in water, the 60 or so species of sea snakes, all bear live young. So there appears to be a simple requirement for reptiles to be fully aquatic: to bear live young.

But that precludes another common reptilian trick, the control of the determination of the sex of their young by the temperature at which eggs are incubated. In crocodiles, the majority of sea turtles and some lizards, the temperature of the environment surrounding their eggs governs whether the hatchling is male or female, as opposed to the presence of distinct sex chromosomes as in many other species.

Since live-bearing reptiles are not able to regulate sex through incubation temperature, this fact raises the question of whether there is a link between the evolution of giving birth to live babies, and the control of sex by genetic means. Chris Organ and Daniel Janes of Harvard, and Andrew Meade and Mark Pagel of the University of Reading, in England, recently examined 94 living species of reptiles, birds and mammals and found that, indeed, there was a very strong link. The genetic control of sex appears then to be a crucial prerequisite to evolving live birth.

Given that link, the scientists then investigated whether they could infer how sex was controlled in ichthyosaurs, mosasaurs and other lines of extinct marine reptiles, each of which evolved from a different ancestor and at different times. Using sophisticated statistical tests, they concluded that, indeed, genetic control of sex was likely to have operated in each group.

The point of the study was not so much the feat of inferring the genetics of long-extinct creatures, but of understanding the steps involved in evolving a fully aquatic lifestyle. Once the genetic control of sex evolved, so could live birth. And with live birth, these animals were freed of the obligation to return to land to nest. That freedom allowed them to evolve large body size, and the fins and fluked tails that made them efficient swimmers. They dominated the open seas.

Easy Nash

In Shia Islam, intellect is a key component of faith. Intellect allows us to understand the creation of God: Aga Khan IV(2008)
The Qur'an itself repeatedly recommends Muslims to become better educated in order better to understand God's creation: Aga Khan IV(2007)
The Quran tells us that signs of Allah's Sovereignty are found in the contemplation of His Creation: Aga Khan IV(2007)
This notion of the capacity of the human intellect to understand and to admire the creation of Allah will bring you happiness in your everyday lives: Aga Khan IV(2007)
Islam, eminently logical, placing the greatest emphasis on knowledge, purports to understand God's creation: Aga Khan IV(2006)
The Holy Qu'ran's encouragement to study nature and the physical world around us gave the original impetus to scientific enquiry among Muslims: Aga Khan IV(1985)
The first and only thing created by God was the Intellect(Aql): Prophet Muhammad(circa 632CE)