Precambrian on the brain

Spent a few hours living in the past during visit to Museum of the Earth (Ithaca, NY).

Did a sketch on the progression of the Precambrian period which is rarely represented to any extent in museums.

Which is weird because that is when life first appeared. Sure, it didn't have the fantastic creatures that started appearing in the Cambrian Radiation (I don't use the more common 'Explosion' because it implies all life magically happened in an instant). But to me it is more intriguing. Partly because we know less about it.

Yet, we do know that what we consider life first began before oxygen filled our atmosphere. Life then was anaerobic: without oxygen. And appeared only in water, not surprising since the planet was mostly covered with water back then. Water is H2O (hydrogen dioxide), but the two hydrogen atoms are tightly held on to the oxygen. So there was little oxygen in our atmosphere (which was then water vapor, methane, and ammonia).

Bacteria, and their appearance, is commonly called the 'first 'life'1. The cog in the wheel is that it depends on how we define 'life', but that's another long topic (which is embroiled in debate within the scientific community). Finding fossils of bacteria have been difficult: partly because they are so small, and partly that most of the rocks from that time period are also rare.

Our planet formed 4.6 billion years ago (Hadean era); a ball of gas, water vapor and hot molten minerals. The planet cooled enough ~4.4 bya for water to appear and cover the planet. A mineral crust began forming ~4.04 bya and the earliest fossils found are dated 3.5 bya.

Between that time (4.2-3.5 bya) the first single cells formed. The Last Universal Common Ancestral (LUCA) cell population from which all subsequent life forms descended is estimated to be 3.5 bya. This is estimated from genome compilation (which implies that genes had to be present!).

But! Before then was a first universal common ancestor (FUCA). A non-cellular entity is proposed to be the earliest organism with a genetic code capable of performing biological translation of RNA molecules to protein formation through peptides synthesis. In other words, it had to contain enough information to copy itself and evolve. Well, how did that come about?

And that is where my keen fascination is ignited. Hence, my interest in the Precambrian period. But much of this is absent from museums. Several hypotheses are tossed around and debated on the process of how life originated. Yet, if we restrict 'life' to the conventional definition (more a perspective) of life, it excludes possible candidates that were integral in that process.

I'm following two scientists active in this search: biochemist Nick Lane and astrophysicist Sara Imari Walker. They think outside the box. But more on that later. 

1. Some scientists posit that progenotes are the 'first life' or the First Universal Ancestor (FUCA) of all life. Philosophically, it depends on one's definition of 'life', which is still debated. There are at least 9 definitions of life, so choose your favorite. A problem associated with defining life in the scientific context of possible origins of life is constraints (top-down) in investigating and understanding the processes from when the planet formed (Hadean eon,) to the FUCA. 

Air Pollution is Us

The dangers of air pollution seem obvious and of concern to some, but apparently only a minority. How much of the apathy is attributed to "I don't care" or "I don't believe it", or both, is unknown. Yet, I see it on a daily basis. 

The most striking is the number of people that leave their gas-powered vehicles running while at stores or other business. On my walk to and from the gym, I pass cars parked on the sides of the street and in the post-office parking lot. It's more common than not to notice that most vehicle engines are on and running with no occupants in them. 

Out of curiosity, I timed 4 empty vehicles independently with engines running (1 at post office, 2 at a barber shop, 1 store parking lot). Vacancy time was 12-32 minutes. The other day 5 running vehicles parked at the post-office were backed into the lot with rear ends butting the sidewalk. Another time I walked passed an engaged car with a passenger in a store parking lot. ~Twenty-five minutes later when I exited the store, the car was still running with it's passenger. I see this year-round, not just seasonal.

I see this ALL the time! Imagine how much emissions are exhausted into the air. I notice during my walks on cold and gray days that the exhaust stays closer to the ground, not dissipating into the air above, and worse on windless days. What that means is that I'm breathing it the entire time I walk along the streets. I can smell and taste it. 

All this in a small rural town. Now, consider the expansion of this in cities and along major highways. This is why I don't like living in urban areas (as well as my hypersensitivity to noise). And it affects more than just us humans; it impacts all life forms. 

Here is an important factoid: a scientist discovered by stringent experiments that lead in the environment was almost nil until the beginning of the Industrial Revolution and increased every year. By sampling the permafrost in Greenland he found that the levels significantly increased in the 1950's, coinciding when lead was added to gasoline. Lead in gas was (is) volatilized in engines and emitted from tailpipes. Therefore, lead was deposited along streets and highways for decades. 

The dangers of lead were known decades before unleaded gas was introduced for on-road vehicles in the 1950's. Yet it took another 20 years for unleaded gas to be phased out completely. Lead use in gasoline was prohibited in the US in 1986.

The problems are: 

1. Lead is a heavy metal and stays in living tissues for some time, depending on how much and long an organism was exposed. High exposure (time and amount) can lead to the metal deposited and stored  in bones and teeth (the two common sources for sampling of lead contamination).

2. Bioaccumulation: lead from air pollution, etc can accumulate in soil and plants, and the organisms that use plants for food source. And lead can persist for hundreds of years.

"Lead shares about 10% of total pollution produced by heavy metals. The uptake of lead by the primary producers (plants) is found to affect their metabolic functions, growth, and photosynthetic activity. The accumulation of lead in excess can cause up to a 42% reduction in the growth of the roots."

Also, lead arsenate and other lead compounds were used as pesticides for food crops,  such as fruit orchards and on other crops, until the 1950s. But that lead in the soil is still there and being absorbed by plant roots. Sampling of plants along highways and streets demonstrate that plants absorb, and some sequester, lead from the air. (Avoid planting edible plants next to roads and highways.)

Pollution particles are not just lead, as this recent science article points out. Yet no one seems to care, considering the amount of pollution generated, knowingly and unknowingly, on a daily basis. Right under our noses.

"The damage that air pollution can do is wide-ranging and well-known: The chemicals produced by human activities can trap heat in the atmosphere, change the chemistry of the oceans and harm human health in myriad ways.

Now, a new study suggests that air pollution might also make flowers less attractive to pollinating insects. Compounds called nitrate radicals, which can be abundant in nighttime urban air, severely degrade the scent emitted by the pale evening primrose, reducing visits from pollinating hawk moths." ("Polluted Flowers Smell Less Sweet to Pollinators, Study Finds," Emily Anthes, New York Times, 2/08/2024)

 

Speaking Out

What convinces me that our species is 'doomed' (I wish I could avoid using that term, but can no longer deny the applicability) is the global pathological denial of the train wreck. Additionally, human civilization has already dragged down other species, and continues to do so at alarming rates.

As a scientist, I intellectually understand that denial is a defense mechanism to help cope with anxiety (coupled with explaining away problems and blaming others). Denial enables ignoring or refusing to believe an unpleasant reality, protecting psychological well-being in any situation that produces anxiety or conflict including challenges to one's standard of living or power status quo. But when one is looking into the jaws of a lion ready to bite off your head, or staring at the giant wall looming before the speeding train, denial no longer serves as a defense mechanism. Here I lose understanding, and I blame my science colleagues as much as the politicians and financiers that perpetuate the fuel of denial.

Most of the scientific community, including medical, is either in denial, or running to look for technological solutions rather than evaluate the root origins of our problems and address 'how we got from there to here.' Our politics, economics, policy, and, many times science are based on 'bandaid' cures. Put a bandaid on it, cover it up, and it will go away. Ignore the festering wound underneath; its origins, the process and interrelated changes of its development. Ignore the peripheral interacting relationships and far-reaching impacts. "Let's amp up production; don't pay any attention to consumption." "Give them a pill; who cares about prevention?" "Collect the species DNA and we can ignore life extinction."

At this rate, our civilization will collapse. As history teaches us, it will also arise again like the Phoenix. But perhaps a Phoenix with a limp. My sympathies and grief are for the non-human species on this planet. Their collapse and extinction is finite. And they have no concept of denial. The ubiquitous law of supply and demand is a part of population dynamics. The changing supply of resources -water, food, shelter- will trigger changes in population. I suspect that without modern industrial sustainment of large scale food production, water collection and long-distance distribution, human population everywhere will decline, possibly quickly collapse. Earlier civilizations, even other species, have experienced these cycles; we are not immune.

Sometimes I have to look beyond the doom and gloom and find specks of hope that we can change this trajectory. But my brain isn't convinced.

No Single Diet for a Big Planet

The increasing pressure for everyone to convert to a vegan diet smacks of ignorance and righteousness. Yes, that includes scientists, and shame on them.

This stated universal solution for the health of everyone on this planet and all the ills of climate change is fraught with negligence to the fact that not every person can subsist in good health on a vegan diet. Nor is it necessary (some bold scientists have published data on why).

While the public, and many scientists, claim that adopting a vegan diet is the most important way to lose weight, be healthy, reverse climate change, and treat the planet better, there are reasons to believe this isn’t always the case. Despite the prevalent binary thinking and judgement of our Western society, fad science, and culture, there is no one, universal, de facto “right” diet for everyone. Our genetics, physiology, medical history, economic status, food accessibility, and aesthetic tastes are vastly varied. Absolutisms are rarely absolute.

Many people have food sensitivities and/or allergies: allergies to peanuts, gluten-related disorders (including wheat allergy and insensitivity to fructans), intolerance to yeast and/molds (such as in leavened breads, beer and several cheeses), phytates in m,any legumes and vegetable (taboo for people prone to kidney stones), “onion intolerance” (sensitivity to ingestion, even dermal exposure, to one or more plants in the Allium family), fructose malabsorption (bad things happen when eating even a small amount of most fruits), legume (including soybeans) intolerance/allergies, and the list goes on. People with these sensitivities and allergies may be unable to commit to a vegan diet without jeopardizing their overall health.

Another topic rarely seen in the lay media, and uncommon in the scientific literature, is the nutrient efficiency of a diet containing even a small amount of animal products - meat, milk, yogurt, cheese, eggs. By comparable weight, animal food products contain more protein (especially in the context of complementary amino acid profile), bioavailable minerals, and energy than any non-animal product. 

The cautionary point here is that most of the consumed energy is in the form of lipids, aka ‘fats,’ especially cholesterol. Primates -yes, us, too- evolved to store dietary fat for emergency energy in cyclic periods of famine. However, in our modern world of convenience and accessible plenty, we no longer need as much, and eat too much of it. Also, removing excess fat and eating naturally lean meat is an alternative.

The loud proclamation that everyone should embrace a vegan diet is unwarranted and impossible for many people. Nor should the reason of significantly reducing our carbon footprint be justification for imposing guilty consciousness. Some people just can't adopt a vegan diet. Moreover, a universally adopted vegan diet will not solve the demand for food and reverse climate change. 

Research at the USDA-Agricultural Research Service found that removing animal protein from the diets of many people would increase nutrient deficiencies that have been associated with certain health risks, like cardiovascular disease. Mary Beth Hall, animal scientist and one of the study researchers  at the U.S. Dairy Forage Research Center, comments in a press release,

“Different types of carefully balanced diets — vegan, vegetarian, omnivore — can meet a person’s needs and keep them healthy, but this study examined balancing the needs of the entire nation with the foods we could produce from plants alone. There’s a difference between what’s possible when feeding one person versus feeding everyone in the U.S.”

More importantly we should put more emphasis on growing some of our own or buying locally produced food, learn to make better food choices, eat balanced meals of both vegetables and animal products, plan meals centered around seasonally available foods, and stop piling so much food on our plates. 

Oh, and spending less time on our devices, in our vehicles, and getting off our butts and moving around around would not only reduce our appetite, improve our health, and possibly shrink that carbon footprint. Add supporting informed policy change at the local, state and national levels, too.

Climate Changes: Interactive River Flow Map

Climate change cometh. This year (so far) has been one of extreme weather nationwide. Rivers are either flooding or drying up (exemplified here in Texas). The interactive map below is borrowed from Climate Central, a website with reliable information on global climate changes.