The Rise of Parental Care

Notes from the 4th class of the Big Ecology Conservation Course by Course Volunteer Bob Herbert

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Big Ecology’s fourth class was presented by Joseph G. Lorenz, PhD and we explored the various levels of parenting that exists between primates and other species.  Humanity is perhaps the pinnacle of evolution on our planet and as Dana pointed out in the first class, our brains consume more energy than any other species, and we learned from Dr. Lorenz that humans are also the slowest to develop.  As the complexity of the human brain has increased, so too has the length of time required to raise a child and prepare them for modern civilization.  It takes humans almost two decades more than any other species to get their offspring ‘out of the nest.’

Parenting behaviors evolve and adapt over time, but the common goal shared by primates and algae alike is the continuation of the species.  Life finds a way, and the higher up the food chain you go (in general), the more complex the role of parenting becomes. 

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Parenting developed as a result of sexual reproduction.  Asexual reproduction only requires a “parent” to split in half, and the two remaining parts share identical DNA.  Asexual reproduction, however, does not allow for the diversification of species the way sexual reproduction does.  The sharing of genetic material through sexual reproduction is the driving force behind the incredibly complex ecosystem we live in.  It explains how so many different species of birds, amphibians and mammals have come to exist.

There are two types of sexual reproduction; external and internal.  Fish are a good example of external fertilization.  The male fish fertilizes the eggs after the female has excreted a large amount of them into the water.  This process may not win him father of the year, and he may not be a scout leader, but thousands of eggs are fertilized at one time and the species perpetuates.  Internal fertilization can result in the laying of an egg, which is the case with birds and reptiles.  Internal fertilization can also result in the mother carrying the offspring inside her womb until she gives birth to living offspring.  The higher up the evolutionary ladder we climb we discover that internal gestation is the preferred method.  This allows for better protection of the young offspring for longer periods of time, as well as increased nutrition via the mother’s blood.  This type of reproduction was necessary to develop higher functioning brains like the ones we find in primates and ourselves.  The placenta provides a direct interface of nutrition between the mother and child, unlike an egg which relies on the finite amount of nutrients available in the yolk sack.

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The more developed the species, the more parenting is needed.  Feeder species like mice are able to produce multiple litters each year and their offspring are expected to be on their own within a matter of weeks.  As a result, they lack the necessary survival skills needed for longevity.  Survival and social skills are both taught by more evolved creatures.  The fact that mice don’t remain by their parent’s side for a year and learn how to increase their chance of survival is how they fit into their niche in the food chain.  When you climb the evolutionary ladder and you arrive at chimpanzees and humans there is an increased amount of energy and time that is required to properly prepare and socialize offspring.

The quantity of offspring produced by different species clearly shows this parenting phenomenon.  Species engaged in asexual reproduction are capable of spawning 500,000,000 offspring per year.  Fish have approximately 8,000 offspring each year, frogs have 200, rabbits have 12, cougars have 2, and primates only average one offspring every five years. 

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The next thing we learned was the classification between ‘r’ species and ‘K’ species.  ‘R’ species are more plentiful and they pursue a life of reproduction based on “quantity.” They can survive in a wide variety of habitats, including “weedy” or disturbed areas.  Mice fit into this category.  “Quality” reproduction is the choice of ‘K’ species and Gorillas and humans both fit into this category.  They are more specialized and don’t respond as well to environmental changes or disturbances as “r” species.”  The difference between small annual plants (‘r’) and mature forests (‘K’) can also be seen in the plant kingdom.  When we look back over long periods of earth’s history we see that the ‘r’ species have had the highest rate of survival, bacteria being the best example of this.  Climate and environmental changes have consistently affected the ‘K’ species more dramatically, to the point of extinction in some cases.  This is a direct result of the amount of parenting required and the number of offspring produced by each species.

Our brain and the brain of all primates has been developing and increasing in size and complexity for two million years.  Chimpanzees are the closest living relatives to humans and in a few film clips of social research we saw that a human baby and a baby chimpanzee show glaring similarities in the way they behave.  We may have lost some hair, but it was apparent that a human infant and a baby chimpanzee’s brains are organized alike.  When the same challenges or stimuli were presented to each, they responded and problem solved in very similar ways.             

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One invention that has arisen through human evolution and is exclusive to our species is grand-parenting.  Because of our longevity, humans reach an age when they are no longer able to reproduce, but we still have a lot of good years left in us.  The human brain allows for the accumulation of knowledge and wisdom throughout our lifetime, which enables grandparents the opportunity to care for and teach the children of our species.  This additional layer of education and care is unique to humanity.  We see shared care amongst primates, however it is not as family driven as it is with humans.  If a parent is killed in the animal kingdom their offspring are often adopted and cared for by other members of their species, but it is based around survival, not continued education and family lineage.  Grandparents offer a fresh perspective for a child, and they bring to the table a lifetime of experience.

The development of agricultural societies drove the need for grand-parenting amongst Homo sapiens.  Hunters and gathers actually spent less time seeking or making food which allowed them more time to raise their young.  Farmers had to spend more time in the fields, which gave them less time to raise their children.  The more complex our society becomes, the less time parents have to raise their children.  As a result, grand-parenting has continued to increase its presence in American society over the past half century.  More and more families have two parents in the work force, which has increased the role that many grandparents take in the lives of their grandchildren. 

We live in a wonderfully complex world that begins under a microscope and ends with primates running around on top of moving tectonic plates of earth.  With the information provided by the first four speakers it is apparent that the world around us is constantly evolving and changing.  Every branch of our evolution has occurred for a reason and after a month of Big Ecology we are beginning to understand more about how the pieces of this amazing puzzle fit together, how we ourselves have evolved, and how we coexist with everything else on the planet. 

Big Biology! (Life’s Co-evolutionary Journey)

Notes from the 3rd class of the Big Ecology Conservation Course by Course Volunteer Bob Herbert 

George Wooten, an ecologist and teacher, presented the third night of the Methow Conservancy’s Big Ecology course, and he did a wonderful job making the microscopic world around us seem really BIG!  The course began three weeks ago with the Big Bang and billions of years of history and science, and last week we focused on the planet and learned about the mechanics of geology.  George took it to the next level and he opened our eyes and mind to the complex and unseen world of single cell organisms, and how DNA has created the incredible diversity we enjoy on earth.

Spotted Lake near Osoyoos contains magnesium sulphate (Epsom salt) that crystallizes in circular patterns during cycles of evaporation (image from GoogleEarth). The lake lies in the Okanogan dolomites, laid down near the Permian-Triassic extinction event of 250 million years ago. These sediments continue south to Omak, where they contribute to the character of the Poison Lakes, including Hot Lake, a polymictic lake that reaches 150 degrees in the summer. Because of the salt concentrations, organisms living in Spotted Lake must tolerate extreme osmotic pressure.

We started by learning about an incredible body of water not far from the Methow that is filled with naturally occurring Epsom salt (magnesium sulphate).  Spotted Lake is covered in a crust of Epsom salt and there are 365 individual pockets of water strewn about, and each one has a unique salinity and chemical makeup.  As a result, biologists are able to study a variety of different types of algae that grow in these unique “petri dishes” provided by Mother Nature.  The Native Americans used the lake for healing purposes, and they believe the 365 pools represent an enlightenment for each day of the year.  The halophiles that live in these pools are microscopic and they are greatly affected by osmosis due to the high salinity of the lake.  Through positive and negative feedback, the halophiles are able to change their body shape in order to adjust to varying osmotic pressures, and they use their whip-like tails (flagella) to move about.

Everything in nature is in balance and interconnected and the pink “watermelon” snow we see on the melting mountain snowpack in summer is a perfect example of this.  Halophiles live in the frozen glaciers on the mountains and they move towards the light and heat on the surface as the spring melt occurs.  Once they arrive at the surface they lose their tails and produce carotenoid pigments which appear red on the snow.  The red halophiles absorb more heat than the white snow, which hastens the melting process.  Individual pools of water form more quickly, which allows for blooms of algae to begin reproducing.  Algae get consumed by protozoans, nematodes, and the food chain is born out of a frozen glacier.

Amoeba with consumed green and blue-green algae. 

Image used with permission of Arturo Agostino (www.microscopeitaly.it).

The next thing we discussed is how we share DNA with the plant kingdom and even algae.  There are 688 overlapping proteins that humans and plants share, which is logical when you consider where life began on earth.  Single cell organisms diversified over millions of years and two kingdoms appeared as a result of that: plant and animal.  The next step up the evolutionary ladder took us to Euglena and Chlamydomonas, and they each developed two tails and eye spots.  They feed on algae so they appear green under the microscope. As single cell organisms began eating smaller single cell organisms like algae and amoebas they created more complicated multi-cell organisms. 

Cell membranes developed over time into semi-permeable surfaces that allowed individual cells to control what went in and out of their membrane.  The membrane is made up of two layers of proteins, and the layers are lined up opposite each other.  There are heads and tails to the proteins and the tails face in towards each other and the heads face towards the outside and inside of the cell.  They are packed together tightly but every once in a while there is a channel located in the membrane that creates a specific sized tunnel through the cell wall.  These channels work as enzymes do with a lock and key mechanism.  They act as ‘gate keepers’ and they are very selective about what they will allow into the cell.

After George opened our eyes to the microscopic world around us and how it developed over hundreds of millions of years, he stepped back and defined life from a biologist’s viewpoint:

1. An organism is any contiguous living system capable of the following functions: Organization / Metabolism (use of energy for consumption, processing, excretion) / Response to stimuli / Homeostasis (maintenance of a stable internal environment) / Growth / Reproduction / Adaptation (maintenance and evolution of beneficial traits).

2. In ecology, a community refers to a group of organisms in a specific place or time.

 

Is it alive? 

Aerial view of Grand Prismatic Spring, Yellowstone National Park. The spring is 300 feet wide at the widest. This photo shows steam rising from hot, sterile azure blue water, while on the margins, the vivid colors are the result of pigmented bacteria in microbial mats. The mats are colored from green to red, depending on the ratio of chlorophyll to carotenoids and on the temperature of the water which favors one bacterium over another.

Back under the scope we continued with a discussion about the building blocks of life, namely carbon.  It turns out that the six electrons and protons and the four attachment points or bonds that carbon provides, creates a geometric shape with endless possibilities for building things.  Carbon is nature’s ‘plastic’ and the molecules formed by carbon structures are much more complex than if they were triangular or tubal in shape, which explains why organic life on earth is carbon-based.

We explored the double helix world of chromosomes next and the closer you look, the more complicated it gets.  Proteins have three structural patterns: Alpha-helix (hair, fingernails), Beta-sheet (silk), and collagen (cartilage, tendons).  We learned how Tubulin is a self-assembling polymer and they are critical for sexual reproduction.  Tubulin guides the chromosomes in cell division.  Peptide chains are created by Ribosomes and they build them by removing the tails from the proteins, while simultaneously linking the heads together.  It is through this incredibly complicated and guided process that genetic expression gives rise to individuality and diversity.

Biologists still do not agree on the origin of life on earth.  LUCA stands for the ‘last common universal ancestor,’ and there are three schools of thought.  Some believe the first life was bacteria and everything evolved from that, while others believe it was Archaea.  Other scientists believe the Genetic Annealing Model which states that prior to organisms there were proto-organisms that were less complex and they exchanged genetic information more freely, which allowed for the diversification of species.  Scientists study the hot springs at Yellowstone National Park in search of the answers to this question, because the algae that grows inside of them is flowing out of a hot spot in the crust.  This unique area provides scientists with a peek into the primordial soup of life.

No last universal common ancestor (LUCA) of life is known. Although this classification has general acceptance, disagreements continue about the rank of the domains and about the LUCA. It is now generally agreed that many of the most primitive forms are polyphyletic, confounding classification.

One of the ways life was able to evolve in bacteria is through horizontal transfer of genetic material.  A donor bacteria connects to the recipient by means of a tube, or pilus.  Only a part of the DNA is transferred, and as a result the recipient bacteria now contains a mixture of DNA.  Scientists believe this is one of the ways life has been able to diversify slowly over hundreds of millions of years.  We discovered that this type of gene transfer also occurs in ferns.  A parasitic flower grows next to the fern and through complex negative and positive feedback, genetic material is exchanged. 

The organic and living world around us is constantly recycling itself back into the smallest building blocks, readying them for reuse.  Fungi live in communities in the soil and they break down dead and decaying plant and animal materials into the smallest usable components, which are protein subunits.  Some fungi live in symbiosis with trees and they receive sugar from the tree in return for the nutrients the host seeds need to grow.  When a tree is dying, however, different fungi will move in and begin breaking down the wood. 

The one thing we all took away from George’s lecture on Big Biology was how interconnected and complex life on earth is.  From the microscopic to the macroscopic, life thrives because of the relationships that exist in nature.  The aspen trees protect their young by creating a taste that is unappealing to the beaver.  Once the trees mature, however, beavers love to eat them, and new aspen shots grow from the downed trees, and thus aspen trees survive well in beaver country.  The deer and the bitter brush also have a symbiotic relationship.  The deer survive the winter months by eating the exposed branches, but underneath the snow new growth is forming on the branches still protected by the snow.  The pellets left by the deer act as the fertilizer that the bush needs for the spring and summer growth. 

The discussion ended with the popular topic of climate change.  George discussed something that has been getting a lot of attention these days, which is what role does methane gas play in climate change?  There are tremendous amounts of methane gas frozen in the Arctic Circle and climatologists fear that when those pockets of gas are released into the atmosphere that it will accelerate the heating process.  The planet is witnessing rapid heating similar to times in earth’s history that preceded mass extinctions.

We have come a long way since the Precambrian explosion that marked the rapid diversification of species 530 million years ago.  One thing is for sure, life on earth is constantly evolving.  Humanity could learn a thing or two from fungi, trees and insects about living in harmony with each other and our environment.  We need to figure out our place in this vast and ever-changing ecosystem of ours and the Big Ecology course is proving to be a great place to expand that understanding. 

Real-World Science Research...from Kids

by Sarah Brooks

I spent last Monday and Tuesday in Seattle setting up our beautiful Art & Experience Auction items at Johnston Architects (don’t miss this cool event in Seattle if you are in the city on the 21^st!).  My drive home on Tuesday was long and slow, with torrential rains over Snoqualmie pass.  The sun started to shine as soon as I turned off Highway 97 and onto Highway 153, like I feel it so often does. 

Tired, I pulled into Twisp just in time to help set up for our First Tuesday for the night.  Little did I realize what an energizing evening it would be.  This was an unusual First Tuesday for us – we were turning over the reins to Methow Valley Elementary School students and their teachers to share experiences from their outdoor science expeditions last year.

In a new program designed to spark student’s interest in science and the natural world, last year Methow Valley  Elementary fourth graders spent two night at the North Cascades Institute’s Mountain School on Lake Diablo and fifth graders enjoyed a magical sailing science trip with Salish Seas Expeditions on Puget Sound. 

The trips sounded amazing – just the sort of thing that might get a young person thinking bigger about the world and their role in it.  On both trips, students were exposed to real-world science research and learned from top-notch science-educators. 

But, what really struck me was the joy exuded by the students.  They wanted to share every detail with us – from what they ate, to what it’s like to live on a boat with your classmates, to every tree they saw on the other side of the mountains.  Every aspect of the multi-day science trip seemed exciting, adventurous, and ultimately joyful…even if it was cold and wet and exhausting.

I wish the whole community could have seen this presentation.  There really is nothing more inspiring, nothing more hopeful, than listening to a whole crew of very thoughtful kids express enthusiasm, respect, and interest in the natural world. 

Methow Valley Elementary plans to do the two trips again this year, with new classes of fourth and fifth-graders.  I hope they’ll want to share their experiences with us again next year and I hope even more people will attend their presentations because you leave with a whole new sense of optimism about the future.

Sarah Brooks serves as Associate Director and realized the other day that she’s been with the Methow Conservancy almost 9 years now.  Wow!  Time flies when you are having fun!

The Blue Planet: Geology and the Pacific Northwest

Notes from the 2nd class of the Big Ecology Conservation Course by Course Volunteer Bob Herbert
The second night of the Conservancy’s Big Ecology course was a fascinating presentation by Alan Gillespie that revealed the dynamic geology of earth.  Like all disciplines in science these days, geologists continue to revise and hone their understanding of how the planet came into being, and how it has changed over time.

            

Basalt in the Columbia River

We learned that rocks are divided up into three categories: igneous, sedimentary and metamorphic.  Igneous rocks are created through the recycling action of volcanoes.  Granite and basalt are both examples of igneous rock.  As tectonic plates collide, the heavier one will dive under the lighter.  As the rock gets forced downward into the mantle of the earth it melts the leading edge of the plate and through a volcanic eruption, it reappears on the surface as lava.  

             

Sedimentary rocks are created through a layering process.  For example, layers of sand build up through wind and rain erosion and with time and pressure they form sandstone.  When sandstone is exposed to the elements it erodes into beautiful and delicate hoodoos and arches, and Utah and Arizona are filled with amazing examples of these.

             

Metamorphic rocks are formed under intense heat and pressure.  Some of the rock crystallizes, while other parts become warped.  When these rocks are exposed, they show banding that is curved and distorted, instead of linear. 

             

We discovered that geology is no different from other disciplines of science in that its origins were found in stories and legends.  These legends served as factual science for the people of that time period and geographic location.  The legends transformed over millenniums, and now they are nothing more than humorous stories about our ancestor’s lack of scientific knowledge, but for a long time this was how science was taught.  One of the main things that these stories provided was a process for how things worked.  It didn’t necessarily have to be correct to sufficiently explain a natural process that people wondered about, like the sun rising and setting every day.  Science is the modern outcome of these campfire stories, and science continues to improve and adjust its understanding of the world we live in.

            

The discovery of radiometric dating opened the door for geology.  This process measures the amount of Carbon 14 found in a rock and through a mathematic equation, the age of the rock is determined.  This discovery allowed geologists to measure the ages of various layers of rocks and fossils and through this data our modern understanding of earth’s geology and plate tectonics was born.  Carbon dating has confirmed that the earth is 4.55 billion years old.

            

The Earth is made of a "core," "mantle," and "crust"

When the earth was originally forming, the heaviest elements sank to the center, which is how our super-heated iron core came into being.  Uranium is found in the transition into the outer core and mantle, and the earth’s crust formed as the surface of the liquid mantle cooled.  Scientists believe that our moon was actually a large meteor passing through our solar system and it slammed into the side of earth.  A portion of earth broke off and the remnants of this collision went into orbit around the planet, giving us our moon.  At the same time, the collision tilted earth’s rotational axis.  It is this tilt that provides the four seasons for our planet.  If earth’s orbit around the sun was perpendicular instead of being tilted at 23.44 degrees, then the weather at your home would remain the same year round.       

             

The rotational velocity of earth (approximately 1,000 mph) combines with the electrical field that surrounds the inner core, and together they create the dynamo that produces the dipolar magnetic field which protects earth from cosmic radiation.  This phenomenon not only provides earth with protection from solar radiation, but it also provides us with magnetic north/south for navigational purposes.  The Van Allen belts are the name of this magnetic field and they are also responsible for the northern lights.              

             

By studying fossil records geologists have confirmed two major extinction periods that occurred 250 million years ago and 65 million years ago.  The oldest is named “Snowball Earth” and it was a massive ice age that covered the entire planet with snow and ice.  As the glaciers receded toward the poles the age of the dinosaurs slowly began.  Giant reptiles dominated the surface, air and oceans until 65 million years ago.  At that point, a meteor is thought to have hit the earth and the dust from the impact blocked out the sun long enough to drive the dinosaurs into extinction.  We are currently living in another period of mass extinction (right now nearly 20,000 species of animals and plants around the globe are considered at high risks for extinction), and unfortunately, humanity seems to be the cause for this one.

             

300 million years ago there was one supercontinent called Pangaea

Geology took another leap forward when it was determined that the continents were joined together about 300 million years ago in one supercontinent named Pangaea.  The crust floats on top of the liquid mantle, and over time it broke into pieces. Over millions of years they drifted apart from each other and created the continents as we know them.  Geologists determined that oceanic plates are heavier and continental plates are lighter, and they are all in motion.  Fault lines have been created where these plates have come together, and when these giant chunks of earth slip against each other they create earthquakes.

             

Even though North America and Asia appear to be seamless pieces of land, they have actually been created through a series of smaller pieces slamming into the larger, main piece.  India is a perfect example of a smaller piece of land crashing into a larger one.  The point of contact for India was in the north and the collision with Asia created the Himalayas.  We also learned that the west coast of North America was not part of the original craton (an old part of the continent), which broke off from Pangaea.  The Rocky Mountains were created when a piece of land drifting east across the Pacific Ocean slammed into the older bit of continent.  The Pacific Crest is another example of how a collision between two plates produced a north/south oriented mountain range in North America.

Another geological discovery that helped explain earth’s ever-changing landscape was hot spots.  The Hawaiian Islands are the most obvious example of this.  Kauai was the first island to form, but as the crust shifted over the hot spot in the mantle, another neighboring island formed, and so on.  This is why the only island with an active volcano is the Big Island, because it is the last island to be created, and it currently sits on top of the hot spot.  We learned that Washington was also over a hot spot at one point in its history.  The basalt created in the Columbia River Basin was from the same hot spot that is now underneath Yellowstone National Park.  The amount of volcanic material (basalt) deposited in Washington from the hot spot was approximately 80,000 times that of the eruption of Mt. St. Helens, and that same plume of heat now drives the geysers and hot springs of Yellowstone.

             

Once all of the big pieces of the west coast were in place, then a combination of volcanic activity and glacial erosion created what we now know as the Methow Valley.  Mt Robinson is actually one of the dividing lines between continental rock and basalt (volcanic) rock.  A quick glimpse on Google Earth confirms the rock to the west of the peak is charcoal grey eroding basalt and the rock to the east is lighter and granite in appearance. 

The upper Methow is U-shaped because it was carved out by glaciers.

The upper valley (Mazama & Lost River) was formed as a result of a glacier 7,000 feet thick that covered the North Cascades, and it began receding 17,000 years ago.  The shape of the upper valley in the Methow is “U” shaped which is indicative of glacial erosion.  Below Carlton, however, the erosion becomes “V” shaped, which indicates erosion from water runoff alone, so the Methow was actually formed by two different geological actions.

The northwest is rich in volcanic nutrients and boasts enormous biodiversity.  The Cascade Range is a wonderful combination of plate tectonics and volcanoes, glaciers, forests and rivers, and thanks to Alan ’s expertise, we all have a better understanding of how the magical Methow came into being.

“Big Ecology: A Short History of Nearly Everything”

Notes from the 1st class of the Big Ecology Conservation Course by Course Volunteer Bob Herbert

Dana Visalli was the first speaker in the Methow Conservancy’s 6-week long Big Ecology course that started on Jan. 28, and he did a wonderful job opening our minds.  We covered fourteen billion years of history, chemistry, astronomy, biology and geology in two hours and it was a humbling experience.  Homo sapiens have only occupied a tiny fraction of time and space when you look at the overall development of the universe, and this is an enlightening way for us to view our existence.  Humanity tends to believe the world revolves around them and their needs, to the point that Aristotle believed the earth was the center of the solar system. 

The Methow Conservancy created the Big Ecology course based on “Big History.”  Big History is a unique approach to the evolution of the universe and it is currently being taught in numerous universities around the globe, and over 50 high schools.  It provides an excellent framework for how we have arrived, and what our place in the universe is.  Instead of breaking down and studying microcosms of the whole picture, big ecology incorporates many disciplines of science and reveals their interdependency through time.

Dana said there were five themes of our evolving universe.  The Universe: 1. has a history & a story. 2. has a direction—increasing complexity. 3.  is emergent—always new. and developing 4. Is ecological: everything is related and connected, and 5.  humans are part of the story.

The Orion Nebula, a well known star-forming region in Orion's belt

Dana broke down the evolution of the universe into eight major thresholds that marked profound increases in complexity and energy concentration.  The first threshold was the beginning, or what many call the “big bang.”  The theory states that all matter in the universe began as one mass the size of a pin head.  Because astronomers have confirmed the universe is expanding, they believe the original pinhead sized mass exploded with great force.

After the big-bang occurred the universe was made up of nothing but hydrogen, the first element of the periodic table.  After a few hundred million years they decided to have a relationship and they formed helium (H2).  When two H fuse to He, the H atoms give up about 1% (0.7%) of their mass—which is transformed into energy.  All life on earth owes its existence to this 0.7% energy release.  With the help of gravity, the rapidly expanding helium and hydrogen began to form stars and galaxies, giving us the second threshold. 

The third threshold is the evolution, over time, of the 92 natural elements.  Additional heavier elements formed during the creation of stars and they included carbon, nitrogen, oxygen, sodium, and magnesium.  It is fun to think that the building blocks for life on earth find their roots in the stars.  Stars collapsed into super novas and the energy from those explosions provided us with the remaining heavier elements found on the periodic table.  All of the elements necessary to form planets existed at this point and with more help from gravity, the solid cores of planets began forming. 

Our home, taken by NASA

The fourth threshold is the creation of the solar system and the earth.  The fifth is the origin of life, and the evidence suggests that this happened only once, indicating that all life is related as it comes from a single ancestor.  It is thought that the conditions for life to emerge existed 4 billion years ago when there was no ozone layer and only a weak magentosphere to block out cosmic radiation and that such conditions no longer exist. 

The sixth threshold occurred when photosynthesis and the production of oxygen began.  This opened up the door to plant life on earth.  The Biologist Lynn Margulis said, “Photosynthesis is undoubtedly the most important single metabolic innovation in the history of life on the planet.” 

Dana called the 7th threshold, “the community of life,” or life working together.  Life continued to evolve from single cell organisms into multi-cell, two-walled organisms that contained DNA.  It was thought that a single cell organism attempted to eat a smaller single cell organism and instead of digesting the cell, it evolved into a two-walled cell with mitochondria.  Separate organisms blended together, creating new wholes that were greater than the sum of their parts.  This marked the beginning of sexual reproduction and the diversification of species on earth.  The seventh threshold occurred when life began growing in communities.  Communities of microscopic bacteria and mold are responsible for breaking down dead materials and recycling the individual elements back to the earth.  100 percent efficiency through recycling is the only reason the universe has been able to survive for 14 billion years, and humanity could learn a thing or two from this model.    
   
The final threshold was the growth of the brain and the emergence of collective learning and symbolic thought.  Organisms moved beyond basic survival and reproduction at this point and began creative thought and expression.  For Homo sapiens this meant the beginning of artwork and language.  One of the most fascinating aspects to the development of the complexity of life on earth is the increasing amount of energy needed at each level of existence.  When you compare the energy densities of galaxies to the human brain we discover that the brain is 150,000 times more energy intensive.  We think of stars as superheated balls of fire and energy, but because they are so huge, their energy density is only 2 erg/second.  As we work our way down in size we find that planets are 75 erg/sec; plants are 900 erg/sec; animals are 20,000 erg/sec; brains are 150,000 erg/sec; and society on earth is 500,000 erg/sec. 

A major point Dana made is that the human brain is an emergent phenomenon that is still evolving.

Dana said all of the events that have occurred to get us from one threshold to another are called “Goldilocks” moments.  These occur when everything needed for change is in the right place in exactly the right amounts (heat, gravity, etc).  These quantum leaps in evolution could not have occurred if any one piece of the puzzle was a fraction of a percent different. 

Society on earth is 250,000 times more energy intensive than stars.  One of the reasons modern civilization creates the largest demand on the universe’s energy is due to the rate of humanity’s consumption, combined with our inefficiencies.  Primitive man needed about 2,000 kilocalories per day.  As we developed into hunters and gatherers we used about 5,000 kilocalories per day.  The development of early agriculture increased the demand to around 12,000 kilocalories per day.  Skip ahead several thousand years, and we are currently using around 260,000 kilocalories/day/person to live in our modern industrial society, more than 1000x the amount needed to sustain the body.  (And, Dana also reminded us that the human population today is 7.1 billion and is growing by 225,000 a day, 80 million people a year.)

Many scientists believe we are in a 6th "mass extinction event."

How has it come to pass that humanity commands so much energy?  Dana said the answer seems to be humans’ unique capacity for collective learning.  He continued, that this then could be the human dilemma: can the powers of symbolic thought, or we could say rational, cognitive thought, master the ancient, genetically-programmed behaviors  (eat, survive, reproduce) that drive animals with smaller brains, and still seem to be a dominant force in humanity today?  Or, in other words, can the very thing - our evolving brain - that has created such an unsustainable pattern of consumption and growth also emerge to become the thing that saves us (and the planet)?

A clear point in Dana’s talk was that the universe is emergent.  New phenomena are always emerging.  An emergent universe is never finished, it is always in process.  Humans have been formed by the forces at work in the universe.  Humans have a place in this story.  We are an emergent work in progress.

One of our ancestor’s hands, from a cave in Altimira, Spain about 17,000 years ago

Stay tuned for notes from the rest of the 6-part course!
See the course syllabus and a fascinating list of resources (readings & films) here