BIOLOGY: Lynn Margulis & Symbiosis In Cell Evolution

Evolution is no linear family tree, but change in the single multidimensional being that has grown to cover the entire surface of Earth.” -Lynn Margulis, What Is Life?   

Biologist Lynn Margulis died on November 22nd. She stood out from her colleagues in that she would have extended evolutionary studies nearly four billion years back in time. Her major work was  in cell evolution, in which the great event was the appearance of the eukaryotic, or nucleated, cell — the cell upon which all larger life-forms are based. Nearly forty-five years ago, she argued for its symbiotic origin: that it arose by associations of different kinds of bacteria. Her ideas were generally either ignored or ridiculed when she first proposed them; symbiosis in cell evolution is now considered one of the great scientific breakthroughs.

Margulis was also a champion of the Gaia hypothesis, an idea developed in the 1970s by the free lance British atmospheric chemist James E. Lovelock. The Gaia hypothesis states that the atmosphere and surface sediments of the planet Earth form a self- regulating physiological system — Earth's surface is alive. The strong version of the hypothesis, which has been widely criticized by the biological establishment, holds that the earth itself is a self-regulating organism; Margulis subscribed to a weaker version, seeing the planet as an integrated self- regulating ecosystem. She was criticized for succumbing to what George Williams called the "God-is good" syndrome, as evidenced by her adoption of metaphors of symbiosis in nature. She was, in turn, an outspoken critic of mainstream evolutionary biologists for what she saw as a failure to adequately consider the importance of chemistry and microbiology in evolution.

As I wrote in the introduction to the first part of the book (Part I: The Evolutionary Idea: "The principal debates are concerned with the mechanism of speciation; whether natural selection operates at the level of the gene, the organism, or the species, or all three; and also with the relative importance of other factors, such as natural catastrophes." These very public debates were concerned with ideas represented by George C. Williams and Richard Dawkins on one side and Stephen Jay Gould and Niles Eldredge on the other side. Not for Lynn Margulis, all the above scientists were wrong because evolutionary studies needed to begin four billion years back in time. And she was not shy about expressing her opinions. Her in-your-face, take-no-prisoners stance was pugnacious and tenacious. She was impossible. She was wonderful.
 
- John Brockman ("Lynn Margulis 1938-2011, Gaia Is A Tough Bitch:" The Edge, 11.23.2011. Image: Artist rendering of cell structure, 2010.

On Breeding: Eremozoic Humanity-Biological Wasteland Earth...

"If any other species behaves like Man we call it a plague." -Terminal Growth In A Finite World

"All measures to thwart the degradation and destruction of our ecosystem will be useless if we do not cut population growth. By 2050, if we continue to reproduce at the current rate, the planet will have between 8 billion and 10 billion people, according to a recent U.N. forecast. This is a 50 percent increase.

We are experiencing an accelerated obliteration of the planet's life-forms-an estimated 8,760 species die off per year-because, simply put, there are too many people. Most of these extinctions are the direct result of the expanding need for energy, housing, food and other resources.

Population growth, as E.O. Wilson says, is "the monster on the land." Species are vanishing at a rate of a hundred to a thousand times faster than they did before the arrival of humans. If the current rate of extinction continues, Homo sapiens will be one of the few life-forms left on the planet, its members scrambling violently among themselves for water, food, fossil fuels and perhaps air until they too disappear. Humanity is leaving the Cenozoic, the age of mammals, and entering the Eremozoic-the era of solitude.

As long as the Earth is viewed as the personal property of the human race, a belief embraced by everyone from born-again Christians to Marxists to free-market economists, we are destined to soon inhabit a biological wasteland.

The populations in industrialized nations maintain their lifestyles because they have the military and economic power to consume a disproportionate share of the world's resources. The United States alone gobbles up about 25 percent of the oil produced in the world each year. These nations view their stable or even zero growth birthrates as sufficient. It has been left to developing countries to cope with the emergent population crisis. India, Egypt, South Africa, Iran, Indonesia, Cuba and China, whose one-child policy has prevented the addition of 400 million people, have all tried to institute population control measures. But on most of the planet, population growth is exploding.

The U.N. estimates that 200 million women worldwide do not have access to contraception. The population of the Persian Gulf states, along with the Israeli-occupied territories, will double in two decades, a rise that will ominously coincide with precipitous peak oil declines.

The resources that industrialized nations consider their birthright will become harder and more expensive to obtain. Rising water levels on coastlines, which may submerge coastal nations such as Bangladesh, will disrupt agriculture and displace millions, who will attempt to flee to areas on the planet where life is still possible. The rising temperatures and droughts have already begun to destroy crop lands in Africa, Australia, Texas and California. The effects of this devastation will first be felt in places like Bangladesh, but will soon spread within our borders.

Overpopulation will become a serious threat to the viability of many industrialized states the instant the cheap consumption of the world's resources can no longer be maintained. This moment may be closer than we think.

A world where 8 billion to 10 billion people are competing for diminishing resources will not be peaceful. The industrialized nations will, as we have done in Iraq, turn to their militaries to ensure a steady supply of fossil fuels, minerals and other nonrenewable resources in the vain effort to sustain a lifestyle that will, in the end, be unsustainable. The collapse of industrial farming, which is made possible only with cheap oil, will lead to an increase in famine, disease and starvation. And the reaction of those on the bottom will be the low-tech tactic of terrorism and war.

James Lovelock, an independent British scientist who has spent most of his career locked out of the mainstream, warned several decades ago that disrupting the delicate balance of the Earth, which he refers to as a living body, would be a form of collective suicide. The atmosphere on Earth-21 percent oxygen and 79 percent nitrogen-is not common among planets, he notes. These gases are generated, and maintained at an equable level for life's processes, by living organisms themselves. Oxygen and nitrogen would disappear if the biosphere was destroyed. The result would be a greenhouse atmosphere similar to that of Venus, a planet that is consequently hundreds of degrees hotter than Earth. Lovelock argues that the atmosphere, oceans, rocks and soil are living entities. They constitute, he says, a self-regulating system.

Lovelock, in support of this thesis, looked at the cycle in which algae in the oceans produce volatile sulfur compounds. These compounds act as seeds to form oceanic clouds. Without these dimethyl sulfide "seeds" the cooling oceanic clouds would be lost. This self-regulating system is remarkable because it maintains favorable conditions for human life. Its destruction would not mean the death of the planet. It would not mean the death of life-forms. But it would mean the death of Homo sapiens.

Lovelock advocates nuclear power and thermal solar power; the latter, he says, can be produced by huge mirrors mounted in deserts such as those in Arizona and the Sahara. He proposes reducing atmospheric carbon dioxide with large plastic cylinders thrust vertically into the ocean. These, he says, could bring nutrient-rich lower waters to the surface, producing an algal bloom that would increase the cloud cover. But he warns that these steps will be ineffective if we do not first control population growth. He believes the Earth is overpopulated by a factor of about seven. As the planet overheats-and he believes we can do nothing to halt this process-overpopulation will make all efforts to save the ecosystem futile.

If we do not reduce our emissions by 60 percent, something that can be achieved only by walking away from fossil fuels, the human race is doomed, he argues. Time is running out. This reduction will never take place, he says, unless we can dramatically reduce our birthrate."

-Chris Hedges, Excerpt: "We Are Breeding Ourselves Into Extinction," Truthdig.com, 3.9.2009. Images: -Michael Rougier, Munich, Germany, LIFE Magazine, 6.1958).

Organism Earth: The Gaia Theory...

The Gaia Hypothesis:

"The entire range of living matter on Earth from whales to viruses and from oaks to algae could be regarded as constituting a single living entity capable of maintaining the Earth's atmosphere to suit its overall needs and endowed with faculties and powers far beyond those of its constituent parts...A complex entity involving the Earth's biosphere, atmosphere, oceans, and soil; the totality constituting a feedback or cybernetic system which seeks an optimal physical and chemical environment for life on this planet."

"To what extent is our collective intelligence also a part of Gaia? Do we as a species constitute a Gaian nervous system and a brain which can consciously anticipate environmental changes?" -James Lovelock (1960s).

"Earth is a perfect planet for life but, according to Gaia theory, this is no coincidence. From the moment life first appeared on Earth it has worked hard to make Earth a more comfortable place to live. Gaia theory suggests that the Earth and its natural cycles can be thought of like a living organism. When one natural cycle starts to go out of kilter other cycles work to bring it back, continually optimising the conditions for life on Earth.

Named after the Greek Earth goddess, Gaia, the theory was developed in the 1960s by scientist Dr James Lovelock. At the time, Lovelock was working for NASA, looking at methods of detecting life on Mars. The theory came about as a way of explaining why the Earth's atmosphere contains high levels of nitrogen and oxygen.

Initially, Gaia theory was ignored, and then later ridiculed by scientists such as Richard Dawkins and Stephen J Gould. However, in recent times stronger evidence for the theory has emerged and Gaia has started to gain support. The theory helps to explain some of the more unusual features of planet Earth, such as why the atmosphere isn't mostly carbon dioxide, and why the oceans aren't more salty.

In its early years Earth's atmosphere was mostly carbon dioxide - the product of multiple volcanic burps. It wasn't until life arrived that the balance began to change. Bacteria produced nitrogen, an inert gas, and photosynthesising plants produced oxygen, a very reactive gas. Ever since that time, about 2,500m years ago, Earth's atmosphere has contained significant amounts of nitrogen and oxygen, supporting life on this planet. The nitrogen helps to keep things stable, preventing oxygen levels from climbing too high and fuelling runaway fires. Meanwhile, the oxygen supports complex life.

Gaia also helps to explain how the oceans are kept in balance. Rivers dissolve salt from rocks and carry it to the ocean, yet ocean salinity has remained at about 3.4% for a very long time. It appears that the salt is removed again when water is cycled through cracks on the ocean floor. This process keeps the oceans' salinity in balance and at a level that most lifeforms can tolerate.

These processes are not thought to be conscious ones, or to favour any one life form over another. Gaia theory simply maintains that Earth's natural cycles work together to keep the Earth healthy and support life on Earth.

Lovelock argues that humans have now pushed Gaia to her limit. In addition to filling the atmosphere with carbon dioxide, we have hacked our way through the "lungs" of the planet (the rainforests) and driven many species to extinction. He thinks we are heading for a very warm world, where only polar regions are comfortable for most life forms. Eventually, he suspects, Gaia will pull things back into check, but it may be too late for the human race.

Feedback Loops:

Feedback loops often appear to keep the planet in balance. One good example of this is the way in which atmospheric carbon dioxide is kept in check. Carbon dioxide is pumped into the atmosphere by volcanoes, and removed by the weathering of rocks (encouraged by bacteria and plant roots in the soil). When it reaches the sea, the dissolved carbon dioxide is used by tiny organisms, known as coccolithophores (algae), to make their shells. When coccolithophores die they release a gas - dimethyl sulphate - which encourages the formation of clouds in the atmosphere.

When atmospheric carbon dioxide levels become too high, coccolithophores get busy, locking up more carbon dioxide in their shells and pumping dimethyl sulphate into the atmosphere when they die - producing clouds which reflect back sunlight and help the Earth to cool. Conversely, if atmospheric carbon dioxide levels become low, coccolithophores reduce their activity. Over the past 200 years mankind has greatly increased atmospheric carbon dioxide levels, and recently there has been evidence that algal blooms in the ocean are increasing. Could Gaia be trying to correct our mistake?

The Gaia Hypothesis has often been described by commentators as one of the most provoking singular ideas to have been put forward in the second half of the 20th Century."

-Kate Ravilious ("Perfect Harmony," Guardian UK, 4.28.2008. Image:-Hieronymus Bosch, Detail from the Triptych: "Garden of Earthly Delights", Museo del Prado, Madrid, 1500 ).