Tag Archives: Γαῖα

Ocean Climate

Ocean acidification is the ongoing decrease in the pH of the Earth‘s oceans, caused by the uptake of carbon dioxide (CO2) from the atmosphere.[2] Seawater is slightly basic (meaning pH > 7), and the process in question is a shift towards pH-neutral conditions rather than a transition to acidic conditions (pH < 7).[3] Ocean alkalinity is not changed by the process, or may increase over long time periods due to carbonate dissolution.[4] An estimated 30–40% of the carbon dioxide from human activity released into the atmosphere dissolves into oceans, rivers and lakes.[5][6] To achieve chemical equilibrium, some of it reacts with the water to form carbonic acid. Some of these extra carbonic acid molecules react with a water molecule to give a bicarbonate ion and a hydronium ion, thus increasing ocean acidity (H+ ion concentration). Between 1751 and 1994 surface ocean pH is estimated to have decreased from approximately 8.25 to 8.14,[7] representing an increase of almost 30% in H+ion concentration in the world’s oceans.[8][9] Earth System Models project that within the last decade ocean acidity exceeded historical analogs[10] and in combination with other ocean biogeochemical changes could undermine the functioning of marine ecosystems and disrupt the provision of many goods and services associated with the ocean.[11]

Increasing acidity is thought to have a range of potentially harmful consequences for marine organisms, such as depressing metabolic rates and immune responses in some organisms, and causing coral bleaching.[citation needed] By increasing the presence of free hydrogen ions, each molecule of carbonic acid that forms in the oceans ultimately results in the conversion of two carbonate ions into bicarbonate ions. This net decrease in the amount of carbonate ions available makes it more difficult for marine calcifying organisms, such as coral and some plankton, to form biogenic calcium carbonate, and such structures become vulnerable to dissolution.[12] Ongoing acidification of the oceans threatens food chains connected with the oceans.[13][14] As members of theInterAcademy Panel, 105 science academies have issued a statement on ocean acidification recommending that by 2050, global CO2emissions be reduced by at least 50% compared to the 1990 level.[15]

While ongoing ocean acidification is anthropogenic in origin, it has occurred previously in Earth’s history.[16] The most notable example is the Paleocene-Eocene Thermal Maximum (PETM),[17] which occurred approximately 56 million years ago. For reasons that are currently uncertain, massive amounts of carbon entered the ocean and atmosphere, and led to the dissolution of carbonate sediments in all ocean basins.

Ocean acidification has been called the “evil twin of global warming[18][19][20][21][22] and “the other CO2 problem”.[19][21][23]

SHIFTING BASELINES AND DYING OCEANS

by DONALD PROTHERO on Dec 19 2012

Climate deniers try to distort or obfuscate the evidence about the changing atmosphere, and it’s not always easy to give overwhelmingly conclusive data that would convince them. In some cases the data are tricky to analyze, or do not have well-documented long-term histories necessary to answer every concern about whether recent weather events are truly unprecedented. The atmospheric system is very complicated, with many different processes operating on short-term, medium-term, and long-term time scales, and not all of it is as well understood as we would like. Thus, the arguments over changes in earth’s atmosphere often reach an impasse.

Not so for the oceans. Although oceans are an even larger system than the atmosphere, we understand them much better. More importantly, we have an excellent long-term record of how the oceans have changed over millions of years from thousands of deep-sea cores, and from the paleontological record of marine fossils that goes back over 700 million years. And unlike the atmospheres, oceans change very slowly over time, since the thermal inertia of water makes the seas very resistant to change except on long-term time scales. In addition, most ocean currents move slowly compared to atmospheric currents. So no matter what you want to make of the data showing atmospheric change, the changes in the oceans are more alarming, since oceans require immense stimuli to cause such change.

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The morality of evolution

The Descent of Man, and Selection in Relation to Sex is a book on evolutionary theory by English naturalist Charles Darwin, first published in 1871. It was Darwin’s second book on evolutionary theory, following his 1859 work, On the Origin of Species, in which he explored the concept of natural selection. In The Descent of Man, Darwin applies evolutionary theory to human evolution, and details his theory of sexual selection, a form of biological adaptation distinct from, yet interconnected with, natural selection. The book discusses many related issues, including evolutionary psychologyevolutionary ethics, differences between human races, differences between sexes, the dominant role of women in choosing mating partners, and the relevance of the evolutionary theory to society.


As a watchman on the tower, I feel to warn you that one of the chief means of misleading our youth and destroying the family unit is our educational institutions. There is more than one reason why the Church is advising our youth to attend colleges close to their homes where institutes of religion are available. It gives the parents the opportunity to stay close to their children, and if they become alerted and informed, these parents can help expose some of the deceptions of men like … Charles Darwin.

Ezra Taft Benson

More than other modern societies, United States relies, even depends, on myth to cement its confidence. Americans are profoundly ahistorical.

Our national myths are representations of identity and the actual instrument of acculturation. This process of acculturation through myth, moreover, is achieved through entertainment: television and movies. The culture of a society—its ethos—defines distinctive patterns of individual and group behavior. Culture shapes the way we look at the world. Whatever our immediate group membership, our final sense of identity is shaped by larger cultural patterns. If we define ourselves according to myth, what kind of worldview has it given us?

First, at the core,  the United States has an essentially religious value system. The primal myth of our origin is that of the “Pilgrim’s Progress,” with the Plymouth Colony completely overshadowing Virginia and its lineal transplanting of British class and caste. We believe that the source and inspiration of America is bound up in religion: religious freedom, but also the moral vantage of Calvin. The impact of Protestant thought is felt in the ways we talk about mission, service, sacrifice, restraint. It underlies the sense that Americans share of serving a higher calling. This underpinning remains dominant today even though it is highly secularized, and transmuted into legal, constitutional language.

Second, Americans still hew a set of specific myths about the United States. One of these is that America is the source of human progress and can achieve perfection as a society. Americans believe that there has never been a society quite like our own. This American “exceptionalism” suggests that we are a people graced with unusual natural endowments. We think of ourselves literally as a “people of plenty.” But our mythology also reminds us that this land was a great “untamed wilderness,” a “land of savagery.” It was the exceptional will, unity and vision of the American people and their beliefs that transformed the landscape. The twin icons of national bounty and national achievement have inspired two senses of an American national purpose: a conviction that the United States should serve as an example to the world, that America and its people are the model for all human development; and an impulse to change the world for good, to become the active agency of human progress. Tyranny and resistance to change are so entrenched in the world that only direct American intercession can shift the direction of history. America’s gifts demand that it assume a missionary role.

In the United States at the turn of the 20th century, Darwinism was greeted with glee because it seemed so compatible with the prevailing ideology of theday,  where robber-baron capitalists like the Carnegies, Mellons, Sumners, Stanfords and yes, even Jack London, could not stop rattling on about how the “survival of the fittest” justified crushing unions, exploiting immigrant labor or being left unregulated to amass huge fortunes while administering monopolies. In the popular ethos of the United States, there is a confusion of Capitalism with the American worship of the individual and the nuclear family. It can be argued that these ideas are related but they are different and independent. According to the American work ethic you only get what you work for, but this is not what Capitalism is. Capitalism is the idea that market forces, carried out by intelligent agents looking for profit (self interest), let by themselves will generate wealth and prosperity for society as a whole. The dichotomy Capitalism/Socialism is actually dated. If one understands socialism as government control of the economy, all, 100%, of the world’s governments are socialist to some degree. In any case, we now live in a competitive society and are often told that to get ahead we require drive, commitment and determination, that we must expend a great amount of energy and, if necessary, use force to get what we want. A ‘survival of the fittest’ mentality is deeply entrenched in our culture. Despite the fact that this Wild West mentality  is a historical byproduct, it is now attributed to Darwin’s Origin of the Species.

Religious fundamentalists are sincere on their view of the World as a battleground between Good and Evil. For them anything that undermines faith in God, specially with regards to children, is utterly evil. The teaching of Science to children, in particular Evolution, is seen as a threat to children indoctrination. Nonetheless,  the attack on Evolution is an attack on Science as a whole. Science is not about what to believe but rather a method to perceive Reality. It is the critical objective look at reality aspect of Science that is perceived as a treat by the religious establishment. However, teaching religious ideas as an alternative to factual descriptions of reality undermines science education by misinforming students about the scientific method — the basis for science literacy.

The scientific method teaches students the fundamentals of science — how to observe data, perform experiments and form scientific theory. Religious explanations for creation are not science – they cannot be confirmed or denied by the scientific method. Teaching them as science confuses and misleads students about the scientific method, thereby warping their ability to live in a technology-driven society

Most people don’t read scientific papers because they are extremely complex. Even college science students have a hard time digesting scientific papers. But what is easy to understand is that, since the bible says this, science says that, therefore science is the devil, and since we hate the devil and our job is to fight him, we must hate science and fight it. Christian leaders can be blind sighted to the outside world at times. All this commotion about a science that goes against the bible. The Bible today, still says that the Earth does not move around the sun as much as it did thousands of years ago. The Bible did not change. At the end of the Middle Ages, Christian leaders threatened heavy punishment to Galileo for suggesting that, based on his scientific evidences, the Earth revolved around the Sun.

Any effort to introduce a theological doctrine into public school science curricula would inevitably offend some teachers and students. After all, a Protestant fundamentalist’s “literal” reading of Genesis would likely differ markedly from that of a Catholic or an Orthodox Jew. Both public school educators and religious leaders should be concerned about the prospect of biology lessons degenerating into debates on Biblical or religious interpretation.

Evolution by natural selection, at its core, works like this: living organisms are characterized by heritable variation for traits that affect their survival and reproductive abilities. This heritable variation originates from the (truly random) process of mutation at the level of DNA. The process of evolution turns out to be largely the result of two components: mutations (which are random) and natural selection (which, again, is not random). It is the joint outcome of these two processes that—according to evolutionary theory—explains not only the diversity of all organisms on Earth, but most crucially the fact that they are so well adapted to their environment: those that weren’t did not survive the process. Because the environment changes overtime, and therefore, what characteristics of life forms are better changes, and it cannot be said in absolute terms that extinct forms are inferior to those present today.

You may find it intuitively difficult to believe that two relatively simple natural processes can produce the complex order we observe in living organisms. But the beauty of science is that it so often shows our intuitions to be wrong. Because nature does not always function according to our common sense or intuition, the scientific method a necessity on the quest of the human race for survival.

Evolution is both a theory and a fact, contrary to simplistic creationist views. How can this be? Evolution is a fact in the sense that it is beyond reasonable doubt that living organisms have changed over time throughout the history of the earth. It is a theory in the sense that biologists have proposed a variety of mechanisms (including, but not limited to, mutation and natural selection) to explain the fact of evolution.

The theory of evolution is a fundamental concept of biology and it is supported by the overwhelming weight of scientific evidence. Simply eliminating evolution from the public school curriculum in order to ease community tensions would do a great disservice to all students. It would deny public school students an adequate science education – which is more and more becoming a necessity for professional success in a high-tech world.

It must be said that there is a propagandistic perversion of language, and there are religious groups that use the language of science to mislead and actually undermine a scientific conceptualization of Reality. Religious opponents of evolution have cloaked religious beliefs in scientific sounding language and then mandating that schools teach the resulting “creation science” or “Intelligent Design” as an alternative to evolution. Intelligent Design organizations are fundamentalist religious entities that consider the introduction of creation science into the public schools part of their ministry. Creation science rested on a “contrived dualism” that recognized only two possible explanations for life, the scientific theory of evolution and biblical creationism, treated the two as mutually exclusive such that “one must either accept the literal interpretation of Genesis or else believe in the godless system of evolution,” and accordingly viewed any critiques of evolution as evidence that necessarily supported biblical creationism. Creation science is simply not science because it depends upon supernatural intervention, which cannot be explained by natural causes, or be proven through empirical investigation, and is therefore neither testable nor falsifiable.

The argument for Intelligent Design (ID) is not a new scientific argument, but is rather an old religious argument for the existence of God, traced back to at least Thomas Aquinas in the 13th century, who framed the argument as a syllogism: Wherever complex design exists, there must have been a designer; nature is complex; therefore nature must have had an intelligent designer. Although proponents of ID occasionally suggest that the designer could be a space alien or a time-traveling cell biologist, no serious alternative to God as the designer has been proposed. The writings of leading ID proponents reveal that the designer postulated by their argument is the God of Christianity. Dramatic evidence of ID’s religious nature and aspirations is found in what is referred to as the “Wedge Document.” The Wedge Document, developed by the Discovery Institute’s Center for Renewal of Science and Culture. The Discovery Institute, the think tank promoting ID whose CRSC developed the Wedge Document, acknowledges as “Governing Goals” to “defeat scientific materialism and its destructive moral, cultural and political legacies” and “replace materialistic explanations with the theistic understanding that nature and human beings are created by God.”

ID fails on three different levels, any one of which is sufficient to preclude a determination that ID is science. They are: (1) ID violates the centuries-old ground rules of science by invoking and permitting supernatural causation; (2) the argument of irreducible complexity, central to ID, employs the same flawed and illogical contrived dualism that doomed creation science in the 1980’s; and (3) ID’s negative attacks on evolution have been refuted by the scientific community.

Because Science wins over Religion on factual description of Reality, the attack on Science is made nowadays on moral grounds.  From the point of view of religious fundamentalists, Science is a competing religion, although a silly one at that. Then the scientific community is under attack with this straw-man argument against evolution:

But if design, conversely, is rational, why do so many scientists reject it? Because this is not an issue of science, but of religion. Their religion is that of materialism and naturalism, and they are under no illusions as to the implications of design.

James M Tour, in the blog entry Layman’s Reflections on Evolution and Creation. An Insider’s View of the Academy, claims insufficient understanding of what he calls Macroevolution. Macroevolution is evolution on a scale of separated gene pools.[1] Macroevolutionary studies focus on change that occurs at or above the level of species, in contrast with microevolution,[2] which refers to smaller evolutionary changes (typically described as changes in allele frequencies) within a species or population. However, contrary to claims by creationists, macro and microevolution describe fundamentally identical processes on different time scales.

Russian entomologist Yuri Filipchenko first coined the terms “macroevolution” and “microevolution” in 1927 in his German language work, “Variabilität und Variation”. Since the inception of the two terms, their meanings have been revised several times and the term macroevolution fell into limited disfavour when it was taken over by such writers as the geneticist Richard Goldschmidt (1940) and the paleontologist Otto Schindewolf to describe their orthogenetic theories.[7]

A more practical definition of the term describes it as changes occurring on geological time scales, in contrast to microevolution, which occurs on the timescale of human lifetimes.[8] This definition reflects the spectrum between micro- and macro-evolution, whilst leaving a clear difference between the terms: because the geological record rarely has a resolution better than 10,000 years, and humans rarely live longer than 100 years, “meso-evolution” is never observed.[8]

As a result, apart from Dobzhansky, Bernhard Rensch and Ernst Mayr, very few neo-Darwinian writers used the term, preferring instead to talk of evolution as changes in allele frequencies without mention of the level of the changes (above species level or below). Those who did were generally working within the continental European traditions (as Dobzhansky, Ernst Mayr, Bernhard Rensch, Richard Goldschmidt, and Otto Schindewolf were) and those who didn’t were generally working within the Anglo-American tradition (such as John Maynard Smith and Richard Dawkins). Hence, use of the term “macroevolution” is sometimes wrongly used as a litmus test of whether the writer is “properly” neo-Darwinian or not.

At the end of his article, Tour makes a reference to the movie, “Expelled. No Intelligence Allowed.”, a pro-intelligent design movie, which among other claims, strongly implies that Charles Darwin‘s ideas led to Adolf Hitler‘s atrocities. Tour asserts that a subset of the scientific establishment is retarding the careers of Darwinian skeptics. He closes citing  Viktor Frankl , The Doctor and the Soul with the comment If Frankl is correct, God help us:

“If we present a man with a concept of man which is not true, we may well corrupt him. When we present man as an automaton of reflexes, as a mind-machine, as a bundle of instincts, as a pawn of drives and reactions, as a mere product of instinct, heredity and environment, we feed the nihilism to which modern man is, in any case, prone.
“I became acquainted with the last stage of that corruption in my second concentration camp, Auschwitz. The gas chambers of Auschwitz were the ultimate consequence of the theory that man is nothing but the product of heredity and environment; or as the Nazi liked to say, ‘of Blood and Soil.’ I am absolutely convinced that the gas chambers of Auschwitz, Treblinka, and Maidanek were ultimately prepared not in some Ministry or other in Berlin, but rather at the desks and lecture halls of nihilistic scientists and philosophers [emphasis added].”

The movie Expelled main theme is that what it calls Darwinism inherently contain the seeds of Nazism, and even more Darwinism equals Nazism. This frighteningly immoral narrative is capped off a la Moore, with shots of the Berlin Wall, old stock footage of East German police kicking around those trying to escape through the wall to the West and some solemn blather by Ben, who calls upon each one of us to rise up in defense of freedom and knock down a few walls in order to get creationism back into the curriculum at American Schools.

From Darwin to Hitler: evolutionary ethics, eugenics, and racism in Germany is a 2004 book by Richard Weikart, a historian at California State University, Stanislaus,[1] and a senior fellow for the Center for Science and Culture of the Discovery Institute.[2] The work is controversial.[3] Graeme Gooday, John M. Lynch, Kenneth G. Wilson, and Constance K. Barsky wrote that “numerous reviews have accused Weikart of selectively viewing his rich primary material, ignoring political, social, psychological, and economic factors” that helped shape Nazi eugenics and racism.

The Discovery Institute, the hub of the intelligent design movement, “provided crucial funding” for the book’s research.[5] The Institute operates DarwinToHitler.com, which promotes the book and intelligent design.[6] Prominent historian and critic of the intelligent design movement, Barbara Forest, states that the book is tied to the DI’s ‘wedge strategy‘ of attacking Darwinian science as morally corrupting.[7] This strategy aims to “defeat [the] materialist world view” represented by the theory of evolution in favor of “a science consonant with Christian and theistic convictions.”[8]

Weikart has appeared in creationist films promoting the book. In 2006, Weikart appeared in Coral Ridge Ministriescreationist film Darwin’s Deadly Legacy in which Weikart claims “Darwinian ideology is the core” of Nazism and D. James Kennedy concludes: “To put it simply, no Darwin, no Hitler.”[9][10] In 2008, Weikart, a supporter of intelligent design,[11] also appeared in Expelled: No Intelligence Allowed.  In fact, scientific theories, even those like Darwin’s that address organic life, are morally neutral.”   Creationist organizations, like Creation Ministries International cite Weikart’s work claiming it shows “extensive documentation of the Darwin–Hitler link.”

There were many nations, such as Britain which embraced Darwinism but saw a considerable number of their population killed trying to eliminate Nazism. There were other nations, such as the Soviet Union, where Darwinism was seen as so dangerous and subversive to State sponsored dreams of social engineering that those who espoused it were killed or exiled and a complete biological fairy tale, Lysenkoism, put into classrooms and agricultural policy ultimately leading to the deaths of millions from starvation.

Now, Christian groups are tying a neutral scientific theory to racism, antisemitism and xenophobia.That is extremely irresponsible and untrue. In fact, Christianity has a stronger link to anti-semiticism and xenophobia than Evolution which is a scientific theory that purports every man is from the same ancestor.

Throughout history, especially in the Crusades, European Christianity has consistently been a xenophobic culture – Jews were expelled out of England, were treated as second class citizens by Christians, and were not allowed to own lands. Black people were expelled by the Protestant Queen Elizabeth during the food shortage in England. Nazi Hitler, had Christianic themes in support of his treatment of the Jews.

The linking of Nazism to Evolution is a dishonest and cheap attempt at trying to personify a scientific theory as the root of all evil in the world. Evolution implies is that every human came from a single ancestor. Darwin himself was anti-slavery and he said that there was “no clear distinctive characteristics to categorize races as separate species, and that all shared very similar physical and mental characteristics indicating common ancestry”. However this went against Christian beliefs of that time. A German philosopher, Georg Wilhelm Friedrich Hegel, who wrote “Life of Jesus”, “The Positivity of the Christian Religion” and thought to be Christian by many critics believed that scientific racism – or the use of science to propose that other races such as blacks are of different heritage and descended from apes “fitted well with the Christian belief of a divine Creation following which all of humanity descended from the same Adam and Eve.

The Bible sanctions slavery, and from the 1820s to the 1850s it was cited in the Southern States of the United States of America to support the idea that negroes had been created unequal, suited to slavery, by writers such as the Rev. Richard Furman, Joseph Smith Jr. and Thomas R. Cobb.” (http://en.wikipedia.org/wiki/Scientific_racism).

Christians are very uncomfortable with the idea that Adam and Eve were Africans – who, by the now debunked scientific racism are deemed to be descendants of apes. This was a central Christian tenet for much more years than evolution was around, and it was the catalyst for the systematic degradation of a particular group of people – the fact that black people were descendants of apes, gave Christians the biblical right to rule over them. Now that evolution has equalized and showed that all men are equal, and given the current taboo of identifying oneself as racist as well as the demise of Scientific racism. Many xenophobic people turn to Intelligent Design as their last ditch attempt to salvage some element of supernatural support for dominion over a certain group of people. This does not mean all Intelligent Design supporters are racists, but it is certainly a comfortable place for xenophobic individuals to channel their energies to.

The Making of Planet Earth – National Geographic Full Documentary

Published on Jun 19, 2013

❶ HD Documentary Channel: For all your Space, Universe, Science and Technology documentaries!

Published on Oct 4, 2013
This edition of COSMIC JOURNEYS explores the still unfolding story of Earth’s past and the light it sheds on the science of climate change today. While that story can tell us about the mechanisms that can shape our climate. it’s still the unique conditions of our time that will determine sea levels, ice coverage, and temperatures.

Ice, in its varied forms, covers as much as 16% of Earth’s surface, including 33% of land areas at the height of the northern winter. Glaciers, sea ice, permafrost, ice sheets and snow play an important role in Earth’s climate. They reflect energy back to space, shape ocean currents, and spawn weather patterns.

But there are signs that Earth’s great stores of ice are beginning to melt. To find out where Earth might be headed, scientists are drilling down into the ice, and scouring ancient sea beds, for evidence of past climate change. What are they learning about the fate of our planet… a thousand years into the future and even beyond?

30,000 years ago, Earth began a relentless descent into winter. Glaciers pushed into what were temperate zones. Ice spread beyond polar seas. New layers of ice accumulated on the vast frozen plateau of Greenland. At three kilometers thick, Greenland’s ice sheet is a monumental formation built over successive ice ages and millions of years. It’s so heavy that it has pushed much of the island down below sea level. And yet, today, scientists have begun to wonder how resilient this ice sheet really is.

Average global temperatures have risen about one degree Celsius since the industrial revolution. They could go up another degree by the end of this century. If Greenland’s ice sheet were to melt, sea levels would rise by over seven meters. That would destroy or threaten the homes and livelihoods of up to a quarter of the world’s population.

With so much at stake, scientists are monitoring Earth’s frozen zones… with satellites, radar flights, and expeditions to drill deep into ice sheets. And they are reconstructing past climates, looking for clues to where Earth might now be headed… not just centuries, but thousands of years in the future.

Periods of melting and freezing, it turns out, are central events in our planet’s history.
That’s been born out by evidence ranging from geological traces of past sea levels… the distribution of fossils… chemical traces that correspond to ocean temperatures, and more.

Going back over two billion years, earth has experienced five major glacial or ice ages. The first, called the Huronian, has been linked to the rise of photosynthesis in primitive organisms. They began to take in carbon dioxide, an important greenhouse gas. That decreased the amount of solar energy trapped by the atmosphere, sending Earth into a deep freeze.

The second major ice age began 580 million years ago. It was so severe, it’s often referred to as “snowball earth.” The Andean-Saharan and the Karoo ice ages began 460 and 360 million years ago. Finally, there’s the Quaternary… from 2.6 million years ago to the present. Periods of cooling and warming have been spurred by a range of interlocking factors: the movement of continents, patterns of ocean circulation, volcanic events, the evolution of plants and animals.

The world as we know it was beginning to take shape in the period from 90 to 50 million years ago. The continents were moving toward their present positions. The Americas separated from Europe and Africa. India headed toward a merger with Asia. The world was getting warmer. Temperatures spiked roughly 55 million years ago, going up about 5 degrees Celsius in just a few thousand years. CO2 levels rose to about 1000 parts per million compared to 280 in pre-industrial times, and 390 today.

But the stage was set for a major cool down. The configuration of landmasses had cut the Arctic off from the wider oceans. That allowed a layer of fresh water to settle over it, and a sea plant called Azolla to spread widely. In a year, it can soak up as much as 6 tons of CO2 per acre. Plowing into Asia, the Indian subcontinent caused the mighty Himalayan Mountains to rise up. In a process called weathering, rainfall interacting with exposed rock began to draw more CO2 from the atmosphere… washing it into the sea. Temperatures steadily dropped.

By around 33 million years ago, South America had separated from Antarctica. Currents swirling around the continent isolated it from warm waters to the north. An ice sheet formed. In time, with temperatures and CO2 levels continuing to fall, the door was open for a more subtle climate driver. It was first described by the 19th century Serbian scientist, Milutin Milankovic.

He saw that periodic variations in Earth’s rotational motion altered the amount of solar radiation striking the poles. In combination, every 100,000 years or so, these variations have sent earth into a period of cool temperatures and spreading ice.

Biomass

Biomass, in ecology, is the mass of living biological organisms in a given area or ecosystem at a given time. Biomass can refer to species biomass, which is the mass of one or more species, or to community biomass, which is the mass of all species in the community. It can include microorganisms, plants or animals.[4] The mass can be expressed as the average mass per unit area, or as the total mass in the community.

How biomass is measured depends on why it is being measured. Sometimes the biomass is regarded as the natural mass of organisms in situ, just as they are. For example, in a salmon fishery, the salmon biomass might be regarded as the total wet weight the salmon would have if they were taken out of the water. In other contexts, biomass can be measured in terms of the dried organic mass, so perhaps only 30% of the actual weight might count, the rest being water. For other purposes, only biological tissues count, and teeth, bones and shells are excluded.

In stricter scientific applications, biomass is measured as the mass of organically bound carbon (C) that is present. Apart from bacteria, the total live biomass on earth is about 560 billion tonnes C,[1] and the total annual primary production of biomass is just over 100 billion tonnes C/yr.[5] However, the total live biomass of bacteria may exceed that of plants and animals.[6][7]

An ecological pyramid is a graphical representation which shows, for a given ecosystem, the relationship between biomass or biological productivity and trophic levels.

  • biomass pyramid shows the amount of biomass at each trophic level.
  • productivity pyramid shows the production or turn-over in biomass at each trophic level.

An ecological pyramid provides a snapshot in time of an ecological community.

The bottom of the pyramid represents the primary producers (autotrophs). The primary producers take energy from the environment in the form of sunlight or inorganic chemicals and use it to create energy-rich molecules such as carbohydrates. This mechanism is called primary production. The pyramid then proceeds through the various trophic levels to the apex predators at the top.

When energy is transferred from one trophic level to the next, typically only ten percent is used to build new biomass. The remaining ninety percent goes to metabolic processes or is dissipated as heat. This energy loss means that productivity pyramids are never inverted, and generally limits food chains to about six levels. However, in oceans, biomass pyramids can be wholly or partially inverted, with more biomass at higher levels.

Terrestrial biomass generally decreases markedly at each higher trophic level (plants, herbivores, carnivores). Examples of terrestrial producers are grasses, trees and shrubs. These have a much higher biomass than the animals that consume them, such as deer, zebras and insects. The level with the least biomass are the highest predators in the food chain, such as foxes and eagles.

In a temperate grassland, grasses and other plants are the primary producers at the bottom of the pyramid. Then come the primary consumers, grasshoppers, voles and bison, followed by the secondary consumers, shrews, hawks and small cats, and finally the tertiary consumers, large cats and wolves. The biomass pyramid is not inverted, but decreases markedly at each higher level.

There are typically 40 million bacterial cells in a gram of soil and a million bacterial cells in a millilitre of fresh water. In all, it has been estimated that there are about five million trillion trillion, or 5 × 1030 (5 nonillion) bacteria on Earth with a total biomass equaling that of plants.[12] Some researchers believe the total biomass of bacteria exceeds that of all plants and animals.[6][7]

Estimates for the global biomass of species and specie groups are not always consistent across the literature. Apart from bacteria, the total global biomass has been estimated at about 560 billion tonnes C.[1] Most of this biomass is found on land, with only 5 to 10 billion tonnes C found in the oceans.[1] On land there is about 1,000 times more plant biomass (phytomass) than animal biomass (zoomass). About 18% of this plant biomass is eaten by the land animals.[13] However in the ocean the animal biomass is nearly 30 times larger than the plant biomass.[14] Most ocean plant biomass is eaten by the ocean animals.[13]

Humans comprise about 100 million tonnes of the Earth’s dry biomass,[29] domesticated animals about 700 million tonnes, and crops about 2 billion tonnes.[citation needed] The most successfulanimal species, in terms of biomass, may well be Antarctic krillEuphausia superba, with a fresh biomass approaching 500 million tonnes,[26][30][31] although domestic cattle may also reach these immense figures[citation needed]. However, as a group, the small aquatic crustaceans called copepods may form the largest animal biomass on earth.[32] A 2009 paper in Science estimates, for the first time, the total world fish biomass as somewhere between 0.8 and 2.0 billion tonnes.[33][34] It has been estimated that about about 1% of the global biomass is due to phytoplankton,[35]and a staggering 25% is due to fungi.[36][37]

 

 

Gaia theory

The Gaia hypothesis, also known as Gaia theory or Gaia principle, proposes that organisms interact with their inorganic surroundings on Earth to form a self-regulatingcomplex system that contributes to maintaining the conditions for life on the planet. Topics of interest include how the biosphereand the evolution of life forms affect the stability of global temperatureocean salinityoxygen in the atmosphere and other environmental variables that affect the habitability of Earth.

The hypothesis was formulated by the scientist James Lovelock [1] and co-developed by the microbiologist Lynn Margulis in the 1970s.[2] While early versions of the hypothesis were criticized for being teleological and contradicting principles of natural selection, later refinements have resulted in ideas highlighted by the Gaia Hypothesis being used in disciplines such as geophysiologyEarth system sciencebiogeochemistrysystems ecology, andclimate science.[3][4][5] In 2006, the Geological Society of London awarded Lovelock the Wollaston Medal largely for his work on the Gaia theory.[6]

Since life started on Earth, the energy provided by the Sun has increased by 25% to 30%;[14] however, the surface temperature of the planet has remained within the levels of habitability, reaching quite regular low and high margins. Lovelock has also hypothesised that methanogens produced elevated levels of methane in the early atmosphere, giving a view similar to that found in petrochemical smog, similar in some respects to the atmosphere on Titan.[15] This, he suggests tended to screen out ultraviolet until the formation of the ozone screen, maintaining a degree of homeostasis. However, the Snowball Earth[16] research has suggested that “oxygen shocks” and reduced methane levels led, during the HuronianSturtian andMarinoan/Varanger Ice Ages, to a world that very nearly became a solid “snowball”. These epochs are evidence against the ability of the biosphere to fully self-regulate.

Processing of the greenhouse gas CO2, explained below, plays a critical role in the maintenance of the Earth temperature within the limits of habitability.

The CLAW hypothesis, inspired by the Gaia theory, proposes a feedback loop that operates between ocean ecosystems and the Earth‘s climate.[17] The hypothesis specifically proposes that particular phytoplankton that produce dimethyl sulfide are responsive to variations in climate forcing, and that these responses lead to a negative feedback loop that acts to stabilise thetemperature of the Earth’s atmosphere.

Currently the increase in human population and the environmental impact of their activities, such as the multiplication of greenhouse gases may cause negative feedbacks in the environment to become positive feedback. Lovelock has stated that this could bring an extremely accelerated global warming,[18] but he has since stated the effects will likely occur more slowly.[19]

James Lovelock and Andrew Watson developed the mathematical model Daisyworld, that shows how temperature regulation can arise from organisms interacting with their environment. The purpose of the model is to demonstrate that feedback mechanisms can evolve from the actions or activities of self-interested organisms, rather than through classic group selection mechanisms.[20]

Daisyworld examines the energy budget of a planet populated by two different types of plants, black daisies and white daisies. The colour of the daisies influences the albedo of the planet such that black daisies absorb light and warm the planet, while white daisies reflect light and cool the planet. Competition between the daisies (based on temperature-effects on growth rates) leads to a balance of populations that tends to favour a planetary temperature close to the optimum for daisy growth.

It has been suggested that the results were predictable because Lovelock and Watson selected examples that produced the responses they desired.[21]

Gaia scientists see the participation of living organisms in the carbon cycle as one of the complex processes that maintain conditions suitable for life. The only significant natural source of atmospheric carbon dioxide (CO2) is volcanic activity, while the only significant removal is through the precipitation of carbonate rocks.[22] Carbon precipitation, solution and fixation are influenced by the bacteria and plant roots in soils, where they improve gaseous circulation, or in coral reefs, where calcium carbonate is deposited as a solid on the sea floor. Calcium carbonate is used by living organisms to manufacture carbonaceous tests and shells. Once dead, the living organisms’ shells fall to the bottom of the oceans where they generate deposits of chalk and limestone.

One of these organisms is Emiliania huxleyi, an abundant coccolithophore algae which also has a role in the formation of clouds.[23] CO2 excess is compensated by an increase of coccolithophoride life, increasing the amount of CO2 locked in the ocean floor. Coccolithophorides increase the cloud cover, hence control the surface temperature, help cool the whole planet and favor precipitations necessary for terrestrial plants. Lately the atmospheric CO2 concentration has increased and there is some evidence that concentrations of ocean algal blooms are also increasing.[24]

Lichen and other organisms accelerate the weathering of rocks in the surface, while the decomposition of rocks also happens faster in the soil, thanks to the activity of roots, fungi, bacteria and subterranean animals. The flow of carbon dioxide from the atmosphere to the soil is therefore regulated with the help of living beings. When CO2 levels rise in the atmosphere the temperature increases and plants grow. This growth brings higher consumption of CO2 by the plants, who process it into the soil, removing it from the atmosphere.

After initially being largely ignored by most scientists, (from 1969 until 1977), thereafter for a period, the initial Gaia hypothesis was criticized by a number of scientists, such as Ford Doolittle,Richard Dawkins and Stephen Jay Gould.[25] Lovelock has said that by naming his theory after a Greek goddess, championed by many non-scientists,[26] the Gaia hypothesis was interpreted as a neo-Pagan New Age religion. Many scientists in particular also criticised the approach taken in his popular book “Gaia, a New look at Life on Earth” for being teleological; a belief that all things have a predetermined purpose. Responding to this statement in 1990, Lovelock stated “Nowhere in our writings do we express the idea that planetary self-regulation is purposeful, or involves foresight or planning by the biota“.

Stephen Jay Gould criticised Gaia as merely a metaphorical description of Earth processes.[27] He wanted to know the actual mechanisms by which self-regulating homeostasis was regulated. David Abram argued that Gould was unaware that mechanism was itself only metaphorical.[28] Lovelock argues that no one mechanism is responsible, that the connections between the various known mechanisms may never be known, that this is accepted in other fields of biology and ecology as a matter of course, and that specific hostility is reserved for his own theory for other reasons.[29]

Aside from clarifying his language and understanding of what is meant by a life form, Lovelock himself ascribes most of the criticism to a lack of understanding of non-linear mathematics by his critics, and a linearizing form of greedy reductionism in which all events have to be immediately ascribed to specific causes before the fact. He also states that most of his critics are biologists but that his theory includes experiments in fields outside biology, and that some self-regulating phenomena may not be mathematically explainable.[29]

Lovelock has suggested that global biological feedback mechanisms could evolve by natural selection, stating that organisms that improve their environment for their survival do better than those that damage their environment. However, in 1981, W. Ford Doolittle, in the CoEvolution Quarterly article “Is Nature Motherly” argued that nothing in the genome of individual organisms could provide the feedback mechanisms proposed by Lovelock, and therefore the Gaia hypothesis proposed no plausible mechanism and was unscientific. In Richard Dawkins‘ 1982 book, The Extended Phenotype, he stated that for organisms to act in concert would require foresight and planning, which is contrary to the current scientific understanding of evolution. Like Doolittle, he also rejected the possibility that feedback loops could stabilize the system.

Basic criteria of the definition of a life-form include an ability to replicate and pass on genetic information to a succeeding generation, and to be affected by natural selection.[30] Dawkins stressed that the planet is not the offspring of any parents and is unable to reproduce.[23]

Lynn Margulis, a microbiologist who collaborated with Lovelock in supporting the Gaia hypothesis, argued in 1999, that “Darwin‘s grand vision was not wrong, only incomplete. In accentuating the direct competition between individuals for resources as the primary selection mechanism, Darwin (and especially his followers) created the impression that the environment was simply a static arena”. She wrote that the composition of the Earth’s atmosphere, hydrosphere, and lithosphere are regulated around “set points” as in homeostasis, but those set points change with time.[31]

 

James Lovelock started defining the idea of a self-regulating Earth controlled by the community of living organisms in September 1965, while working at the Jet Propulsion Laboratory in California on methods of detecting life on Mars.[38][39] The first paper to mention it was Planetary Atmospheres: Compositional and other Changes Associated with the Presence of Life, co-authored with C.E. Giffin.[40][41] A main concept was that life could be detected in a planetary scale by the chemical composition of the atmosphere. According to the data gathered by the Pic du Midi observatory, planets like Mars or Venus had atmospheres in chemical equilibrium. This difference with the Earth atmosphere was considered to be a proof that there was no life in these planets.

 

Lovelock formulated the Gaia Hypothesis in journal articles in the 1970s[1][2] followed by a popularizing 1979 book Gaia: A new look at life on Earth. Until 1975 the hypothesis was almost totally ignored. An article in the New Scientist of February 15, 1975, and a popular book length version of the hypothesis, published in 1979 as The Quest for Gaia, began to attract scientific and critical attention.

 

Lovelock called it first the Earth feedback hypothesis,[26] and it was a way to explain the fact that combinations of chemicals including oxygen andmethane persist in stable concentrations in the atmosphere of the Earth. Lovelock suggested detecting such combinations in other planets’ atmospheres as a relatively reliable and cheap way to detect life.

 

 

Symbiosis

Published on Jun 28, 2013


Symbiosis (from Ancient Greek σύν “together” and βίωσιςliving“)[1] is close and often long-term interaction between two or more different biological species. In 1877, Albert Bernhard Frank used the word symbiosis (which previously had been used to depict people living together in community) to describe the mutualistic relationship in lichens.[2] In 1879, the German mycologist Heinrich Anton de Bary defined it as “the living together of unlike organisms.”[3][4]

The definition of symbiosis is controversial among scientists. Some believe symbiosis should only refer to persistent mutualisms, while others believe it should apply to any types of persistent biological interactions (i.e. mutualistic, commensalistic, or parasitic).[5] After 130+ years of debate,[6] current biology and ecology textbooks now use the latter “de Bary” definition or an even broader definition (i.e. symbiosis = all species interactions), with absence of the restrictive definition (i.e. symbiosis = mutualism).[7]

Some symbiotic relationships are obligate, meaning that both symbionts entirely depend on each other for survival. For example, many lichens consist of fungal and photosynthetic symbionts that cannot live on their own.[3][8][9][10] Others are facultative, meaning that they can, but do not have to live with the other organism.

Symbiotic relationships include those associations in which one organism lives on another (ectosymbiosis, such as mistletoe), or where one partner lives inside the other (endosymbiosis, such as lactobacilli and other bacteria in humans or Symbiodinium in corals).[11][12] Symbiosis is also classified by physical attachment of the organisms; symbiosis in which the organisms have bodily union is called conjunctive symbiosis, and symbiosis in which they are not in union is called disjunctive symbiosis.[