What the hell has microbial life been doing for ~4 billion years?
(No seriously, email me if you know the answers.)
It can be said with reasonable certainty that biologists study life. Yet after centuries of work, 87-99.999% of all
existing species on Earth remain undiscovered.
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Also, many of these undiscovered species are in the process of dying
out, and it may surprise you to know that biologists cannot study living things once they go extinct. Now dear
reader,
I tell you, there are the consequences of undiscovered life going extinct, especially if they leave no footprint
behind as evidence of their prior existence.
I fear the consequences. I fear for emerging biologists as the possibility of undiscovered organisms going extinct
threatens the progress of science. The future of biology depends on establishing new model organisms because the
continued use of older models
generates a reductionist view of life rather than a comprehensive one. An extinct
lineage will not become living tools for understanding life and will not have potential for applications outside of
biology. It is an uncomfortable situation for both basic and medical scientists.
The sixth mass extinction looms over all life on Earth
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, but what can we do about it? Most people deal with the
extinction problem by tackling environmental issues. However, I choose to find as many undiscovered organisms as I
can
before they go extinct. Consider the following situation:
You are dehydrated in a desert and come across a pail of water. This pail is held by a demon who is slowly pouring
all
the water out of the pail, which saddens you. You spend all your time figuring out how to stop the demon from
wasting
all your delicious water. Then I, also dehydrated, cup my hands, and drink as much water as possible before it falls
into the desiccated sand.
Most biological interests stem from animal life, specifically vertebrates. We can term this phenomenon “vertebrate
elitism.” This is not surprising because humans have an inherent bias to study humans. Understanding who we are and
where we came from are central questions every infant asks when they come out of the womb. Also, we may have
invested
interest in not dying, thus arises medical research. But I study life that is not human, animal, or plant. The
microbes.
Why? Why waste my time? Should I cease ranting and become a vertebrate elitist?
I’ll answer this question by showing where you and the vertebrates fit in the grand scheme of life on
Earth:
Why study microbial life?
Life is cellular based by necessity. You were told as a child that cells are the basic unit of life, but you are not
told why. I answer with a question: What happens when you remove the membrane from a cell? Well, a soup of molecules
surely can’t form a living system… right?
We can accurately make these assumptions:
Starting at ~4 billion years ago on Earth, the first living cells were comparatively simplistic to cells now. These
“simple” cells quite simply ruled the world by themselves for two billion years, influencing the physical structure
of
the Earth. Life gets more complicated over time and we now know these as bacteria, which arguably still rule the
world. A major event happened ~1.8 bya when a small group of these cells evolved into the eukaryotic lineage, single
cells that are huge and tend to organize complex processes into specialized compartments. Eukaryotes are quite
impressive because of what they have accomplished. Eventually, different groups of single celled eukaryotes
transitioned to giant multicellular organisms you know as plants, fungi, and animals. Being multicellular is not
unique, it happens when cells stick to each other. Multicellularity was not a new innovation
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; it was just a natural
progression. Bacteria can do it. You’re
not special in the multiple cells aspect.
As you see, the story of microbes is the story of life and the story of your elite vertebrate origins. We can use
microbes as portals to bring some clarity to 4 billion years of life’s history and investigate their co-existence
with
all eukaryotes. Because eukaryotes emerged among a bacterially ruled world, they evolved to interact with,
eat, or symbiose with bacteria. Our own bodies contain trillions of bacteria both inside and out. We rely on them,
and
we kill them. They colonize us, and they kill us. Such is the nature of life and co-evolutionary processes.
In recent years microbes have received much deserved attention. This revealed the extreme diversity of bacteria and
their role both in the environment and inside other organisms. Microbial eukaryotes, or protists, seemed to gather
less attention and it is surprising the lack of researchers in protistology, as it is a field rich in the prospect
of
discovery. I believe this stems largely from the lack of proper education about eukaryotes. But protists play major
roles in aquatic and terrestrial environments as well as the human microbiome. They range from parasitic and
commensal
relationships to free-living drivers of nutrient cycles and stabilizers of the biosphere. Protists are the most
understudied yet most phylogenetically diverse eukaryotic life on the planet. They are gold mines for their
uniqueness
in genetics, morphology, and production of complex bioactive molecules. Yet when protistologists around the world
gather for a conference, it is only a couple hundred people.
Why study protists? A call to action:
[Protists Are Not Just Big Bacteria]
[Protists Are Microbes Too]
[Bioactive Molecules From Protists]
[Microbes and Climate Change]
[Field Research Is Needed]
[Neglected Protist Pathogens]