Are Mushrooms the Least Complex Organism That We Consume?
I wondered about this ever since I overheard a conversation a group were having somewhere that I can't remember anymore. One guy claimed that mushrooms were the least complex organism that we eat. He went on to substantiate his claim stating "well, we don't eat viruses". I'm not molecular biologist but would love to know the (an) answer.
Great question, and the answer is no.
The classification of fungi really gives you your answer. Yeasts, molds and mushrooms are all fungi, and fungi are organized into phyla based on the complexity of their sexual reproductive systems, and the amount of time spent in each of the reproductive phases. The bread yeasts or nutritional yeasts (zygomycota) are far less complex than the morel phylum (ascomycota) and even less complex than the major mushroom phylum (basidiomycota) in this regard.
To get a little more specific, yeasts are single-cell organisms, for the most part. In contrast, both algae and mushrooms are multi-celled.Yeasts reproduce asexually; mushrooms have as many as 36,000 sexes and a distinct three-stage reproductive process (more distinct in its stages than humans actually). That's a good amount of complexity.
A lot of people chomp down on nutritional yeast (saccharomyces cerevisiae, the baking/brewing yeast) -- right out of the container, or put it on top of popcorn, so yeast gets my vote.
Further, if one looks at the vast physical differentiation of all the species within the major mushroom phylum (or more properly, division), it seems there is some rather sophisticated structural programming going on far beyond that of algae or yeast.
Moreover, consider the sophisticated metabolics of some mushrooms -- those that possess powerful immune-enhancing and anti-cancer medicines, clean up oil spills (though bacteria are also used for this), filter gray water, and recover habitats by holding onto moisture, releasing nutrients, and attracting bird and insect life -- all processes by which an ecosystem is revitalized.
As Quine has mentioned, the mushroom itself is merely the fruit -- only the top part of what may be an enormous mycelial colony under the earth. In fact, the single largest organism on earth is one "mushroom" in the Malheur National Forest (armillaria ostoyae, known as the honey mushroom), that covers 2200 acres -- the size of 1,665 football fields -- and is estimated to be anywhere from 2400 to 8500 years old. The vastness does say something -- the way that particular fungus is inter-reacting with the wide variety of other species it shares space with in the forest.
Paul Stamets is quite the mycologist, and proponent of the "intelligence" of mushrooms. I've seen him talk -- what he says is quite profound, and perhaps directly answers your question: "What the mycelium does, and its ability to adapt, and the products it provides for repairing ecosystems, suggests far more than a disinterested organism of casual importance."
Think about the differentiated parts - like roots and stems. These organs add to an organism's complexity. I believe plants are considered to be more complex than fungi.
Yeast, bacteria (cultures) and algae are pretty primitive. I believe all 3 have examples as single-celled organisms. But as for chowing down on something on it's own, my vote is for seaweed. I think seaweed usually has just 1 type of tissue (no organs), and I know photosynthesis evolved in the ocean first.
Chinon00 is right, although some organisms do have more layers of organization than others they are not necessarily more 'complex,' for example the number of cells they are made of says little to nothing about their evolutionary history--some viruses and bacteria, with short generational lifetimes, are replicating and adapting all the time therefore could be considered the most complex. Size also has little to do with the size and organization of an organism's genome.
And I think consuming yeast in bread or nutritional yeast on popcorn is about even with eating mushrooms; after all, I usually do not just eat plain mushrooms by themselves, either.
Yes an important question in this whole thing is what is "complex"? Unfortunately the man who made the original statement isn't here to enlighten us on just what he meant. Surfing around I found this:
An organism is any individual living entity. Organisms range in size and complexity from microorganisms to multicellular plants and animals. Modern biologists classify Earth's organisms into five kingdoms on the basis of common patterns of the design of life, that is, in their cellular and sub-cellular organization, metabolism, reproduction, and behavior. Listed in order of their earliest appearance in the fossil record of life, these kingdoms are:
1. Monera or prokaryotic microorganisms, which do not have their genetic material organized within a bounded organelle called a nucleus, along with other distinctive characteristics. Earth's simplest organisms occur in this group, in particular viruses, which consist of little more than a proteinaceous shell containing nucleic acids. Viruses are incapable of reproduction without parasitizing the metabolism of an unrelated host cell. Other major groups of monerans are blue-green bacteria and true bacteria.
2. Protista are a diverse group of microorganisms, containing the simplest of the eukaryotic organisms, which have an organized nucleus, one or more flagellae, and generally contain mitochondria and plastids. The most representative group is the protozoans, but some flagellated fungi and algae are placed within this group.
3. Fungi are a diverse group of non-flagellated, unicellular or multicellular organisms, ranging in complexity from single-celled yeasts, through multicellular but microscopic fungi growing as a thread-like mycelium, to relatively complex fungi that develop large mushrooms as their reproductive structures.
4. Plantae, or green plants, utilize solar radiation trapped by chlorophyll or other pigments to fix simple mineral nutrients into energy-rich biochemicals in a metabolic process called photosynthesis. Organisms in this diverse group range from unicellular algae, through multicellular but non-vascular algae, liverworts, and mosses, to vascular plants such as ferns, conifers, and flowering plants.
5. Animalia, or multicellular animals, are heterotrophic organisms that are capable of movement, often in response to sensory stimuli, and with other distinctive characteristics. Animals range in size and complexity from small sponges and arthropods to large vertebrates weighing tons.
All of Earth's organisms are related to varying degrees, sharing certain commonalities of physiology and other functions. Moreover, it is clear that some of Earth's distinctive organisms have a relatively ancient lineage that extends far back into the geological past, while other organisms are enormously more complex in biological organization than others. However, the modern, evolutionary interpretation of life suggests that none of Earth's organisms are "higher" or more "primitive" than any others, and that none have greater intrinsic value.
Evolution has not occurred as a progression of types of organisms that represents a logical, directed succession from simple organisms (such as viruses and bacteria) to much more complex organisms (such as birds and mammals). Earth's diversity of living organisms utilizes body and metabolic plans of varying complexity, but all species represent successful adaptations to the planet's habitable environments.
So single cell to multicellular is "more complex". But I'm still not sure where plants and fungi rank from this write-up.
Also, I think that he probably was talking about a food that's eaten on it's own. So yeast and bacteria used in fermentation to make bread beer and yogurt wouldn't qualify. Although per the write-up I've referenced yeast is fungi.
err what planet is he on? we eat viruses everyday on all the foods we eat. Now if he meant intentional.....
I guess I would also question what he meant by complex organism. Mushrooms are the "fruit" of am organism. So is a rice, a fruit like and apple....simple sugars, starches etc.
Right, and the yeast in bread. (I'll never forget a vegetarian friend of mine reading the label on a yeast packet while she was making bread with me, and realizing that yeast is a living organism that you kill when you bake it.)
After reading Michael Pollan's "The Omnivore's Dilemma", I'm confused about how to classify a mushroom.
Not to mention, I'm not sure how to define compexity. Is a jellyfish really more complex than yeast?