Spiritual Meaning of Fungus

Fungus is a kind of decaying matter of irregular shape and distribution in the form of organized mass. In biology, Fungus is a kind of plant without leaves, roots or chlorophyll that relies on other organisms to gain food. The name of Fungus comes from the Latin “spuma” which means foam. Around 1.5 million kinds of fungi are now known, with the count still growing.

Fungi are common and exist in almost every environment where there is moisture, from the oceans to the arctic. When seen in the right circumstances, they can appear otherworldly, but more often than not, they occur unseen by the naked eye and are overlooked. Fungi are an integral link in nature’s food chain, often providing sustenance to animals, including humans, and many species of fungi are now known to be medicinal. Know about; Red Mushroom Spiritual Meaning, Mushroom Symbolism Meaning.

Spiritual Meaning of Fungus

Fungus has a long history of spiritual meaning. It is often associated with the earth and its ability to grow and blossom from seemingly nothing, as well as with decay, death, and the cycle of life. Fungus is often used in rituals that attempt to reconnect with nature or connect people with their ancestors.

In many cultures, fungus is considered sacred because it can be found growing on dead trees and in other places where life seems unlikely. This association with death makes it especially important for those who wish to communicate with their ancestors or understand the cycle of life better.

The spiritual meaning of fungus is that it represents the mysteries of life. If you are looking for guidance or for a deeper understanding of what you’re experiencing, look no further than the fungus. Fungus is all about growth and evolution; it’s about letting go of the old and letting in the new.

Fungus also represents the connection between heaven and earth—the connection between our physical bodies and our spiritual selves. It’s a reminder that we are all connected, even if we don’t always see it.

Fungi are intriguing organisms with a wealth of diversity in their morphology and ecology. Determining the fundamentals of their biology from a biblical perspective is a daunting but achievable task. This paper seeks to address the topic of fungal kinds by examining recent taxonomic data combined with new insights into the basic biology of the various types of fungi. Fungi can exist as single or multi-celled organisms, reproduce asexually and/or sexually, and can live in varying levels of intimacy with other species.

To work toward a biblical creation model for mycology, this paper will address several questions. First, what was the originally intended role of fungi in creation, and when were they created? What can our current understanding of their symbiotic interactions with other organisms tell us about their original creation? How did pathogenicity arise as a trait of fungi? Answers to these and other questions will foster a more detailed and proper understanding of these important organisms and their relationship to creation as a whole.

Introduction

The theory of evolution is the prevailing paradigm in biology. According to this framework, all living things can trace their lineage back to a single common ancestor approximately 3 billion years ago, resulting in what Darwin called the “Tree of Life.” This has been the dominant paradigm in biology for the past 150 years, although there is a current debate on whether the Tree has a single root or exists as a web (Lawton 2009). In fact, current alternatives more closely resemble the Creation Orchard view (DeWitt 2007). To synthesize a comprehensive alternative to the materialistic Darwinian worldview regarding the history of life, all facets of biology must be considered. Toward this end, this manuscript will address the fungi, a fascinating group of organisms that have received scant attention in the biblical creation worldview to date.

Until relatively recently, fungi were considered to be part of the plant kingdom. This was mainly due to certain shared characteristics, such as apparent lack of motility, absorptive nutrition, and cosmopolitan distribution. It was not until the early 1700s that microscopic observations of fungi led to their classification as a separate taxonomic entity. Currently, it is estimated that approximately 1.5 million species of fungi exist, yet less than 10% of these have been described (Buckley 2008; Webster and Weber 2007). The unifying traits of true fungi are: eukaryotic nuclei; non-photosynthetic, heterotrophic, absorptive nutrition; a non-motile vegetative state; a cell wall made of chitin or chitosan; sexual reproduction by spores; and hyphal or yeast growth.

Genesis of the Fungi

In the materialist narrative of the history of life, fungi arrived on the scene approximately 1 billion years ago, with the earliest fossilized fungi identified in the Ordovician stratum dated approximately 460 million years ago (Redecker, Kodner, and Graham 2000). The current concept of fungal evolution places them as a relative of the animal kingdom, with the Choanoflagellates or true slime molds, being the last common ancestor between the animal and fungal taxa (Baldauf and Palmer 1993). Since that time, the true fungi have supposedly evolved into as few as four (Webster and Weber 2007) or as many as seven (Hibbett et al. 2007) different phyla. The best-described phyla are the Ascomycetes and Basidiomycetes, of which the best-known members are the molds and mushrooms, respectively. These phyla demonstrate the complicated nature of fungal taxonomy, with unicellular yeasts and multicellular forms included as members of both phyla.

In the biblical creation worldview, fungi were created by God during Creation Week approximately 6,000 years ago as a variety of different reproductively isolated kinds or baramin (bara = created, min = kind; Marsh 1941). The Bible does not describe precisely when these organisms were created, but we can logically deduce when they were likely created based on the reasoning that each created system at the end of each day was complete or “good” (Genesis 1; Gillen 2008). In this way, we can deduce that the mycorrhizal, endophytic, and land-dwelling saprophytic fungi were likely created on Day 3 along with plants, while other fungi (that is, animal-associated Candida spp. and the aquatic Chytridiomycetes) were created on Days 5 and 6. Alternatively, all of the fungi may have been created on Day 3 with the other “plants,” given the traditional Hebrew inclusion of fungi and bacteria in the plant kingdom (Gillen 2008; Kennard 2008). Irrespective of their day(s) of creation, discerning the individual baramin of fungi may be possible based on their mode(s) of reproduction and physical characteristics.

Red Mushroom Spiritual Meaning

The red mushroom is a powerful symbol of transformation, renewal and spiritual awakening. It is also known as Amanita muscaria, which literally means “fly agaric.” Shamans in Siberia and other regions of Asia have been using this fungus’ psychoactive alkaloids for thousands of years. The red mushroom has been used in rituals to bring about changes in consciousness and to facilitate healing. It is also associated with shamanic journeys and the ability to explore other worlds.

The red mushroom may be seen as the physical manifestation of the spirit world, or it can represent the body itself. The red color of this fungus indicates that it is a powerful healer that can help with illnesses such as cancer or AIDS. The mushroom may also represent regeneration and rebirth, particularly after death or an illness has taken place in one’s life.

Red mushrooms also have their own unique meaning. They can represent passion, desire, ambition, power and courage.

Role of Fungi in Creation

Fungi have been isolated from every ecological niche on earth. They are able to survive temperatures ranging from about −12°C to 62°C and are found in virtually all latitudes and altitudes. A major activity of fungi is decomposition of organic matter: up to half of the organic matter in tropical rainforests is degraded by fungi (Buckley 2008). This purpose of fungi cannot be overstated. These organisms are crucial for the breakdown of the stable biopolymer cellulose, which is the most abundant biopolymer on earth. Roughly 40% of plant cell wall material is comprised of cellulose (Deacon 2006), making the decomposition of cellulose crucial for nutrient cycling in nature.

The purpose of fungi in recycling organic material is consistent with an originally perfect creation. In the current debate between philosophical naturalism and biblical creationism, an important sticking point involves the relationship of life and death in the history of the universe. In the evolution paradigm, death is a necessary means of progress for the advancement of organisms from simple to more complex. As part of the process of natural selection, it is a tool to allow for the adaptation of organisms to various environmental niches. This stands in contrast to the role of death according to the Bible, where death is an enemy that will be destroyed when all of creation is restored to its original state after Christ’s return (1 Corinthians 15:26). This highlights the incongruity between the biblical creation and evolution worldviews: if spiritual and physical death are not a consequence of sin, then the Christian faith is vain because Christ had no reason to die and rise again. Therefore, the role of death in biology is crucial in this worldview debate.

Biologically speaking, there are differences between the modern and biblical concepts of death. The modern definition of death is the cessation of life, where life is “the property or quality that distinguishes living organisms from dead organisms and inanimate matter, manifested in functions such as metabolism, growth, response to stimuli, and reproduction” (Morris 1982). However, this is not the definition of death used in the Hebrew Old Testament. In the original Hebrew, death (mût) exists in relation to those organisms with a living soul (nephesh chayyah): humans and vertebrate animals (Todhunter 2006). Before the Fall of Adam into sin, living souls did not cease to exist (hence, death did not exist; 1 Corinthians 15:21, 22). Since plants were not created with a living soul and were given for food (Genesis 1:29–30), it is logical that a mechanism to process the inedible plant material and animal waste would exist to allow for efficient recycling of their nutrients.

The symbolism of mushrooms is very ancient and it can be found in many cultures. The mushroom symbolizes the connection between heaven and earth, as well as the connection between the physical world and spiritual world. It is also a symbol of fertility, rebirth and resurrection.

Mushroom Symbolism Meaning

The most common interpretation of the meaning of mushroom symbolism is related to fertility and rebirth. Because they appear after rainstorms and storms when thunderbolts from heaven have disturbed the ground, mushrooms have long been associated with immortality or eternal life in many cultures around the world. Similarly, ancient Romans believed that mushrooms could be used for healing purposes because they appeared after lightning strikes.

In other cultures around the world, people thought that mushrooms were gifts from gods or demons to aid them in finding food or shelter during harsh winters or times of famine. For example, some Native American tribes thought that every time there was a thunderstorm at night, their ancestors came down from heaven on clouds carrying baskets full of mushrooms, which gave them strength during winter months when there wasn’t enough food available in forests due to snowfall and cold weather conditions

In addition to their role in nutrient cycling, fungi also participate in important commensal relationships. Scientists estimate that >75% of vascular plants have symbiotic relationships with fungi in the form of mycorrhizal interactions (Prescott, Harley, and Klein 1993). If endophytic and other commensal interactions are included, fungi engage in intimate associations with approximately 60% of all plant species (Buckley 2008). Fungi are also involved in symbioses with animals, although these types of relationships are not as widespread (Aanen and Boomsma 2006; Akin and Borneman 1990; Deacon 2006; Wubah, Akin, and Borneman 1993). These types of interactions tell us something more about the original purpose of fungi in creation. Indeed, because the original creation was “very good,” we might expect intimate associations of fungi with other organisms in which both benefit.

Fungal Associations with Plants

Mycorrhizae

Many beneficial interactions exist between plants and fungi. Much research has been done to explore these relationships, and they can be characterized as either mycorrhizal, endophytic, or lichen. Mycorrhizae (“fungus root”) are a type of symbiotic relationship whereby plants provide the fungus with carbon, and the fungus extends the reach of the plant in the soil for needed water and nutrients (Buckley 2008). Recent research has demonstrated that mycorrhizal fungi also confer enhanced resistance to numerous soilborne plant pathogens, including other fungi and nematodes (Agrios 2005).

The type of mycorrhizal interactions is either ectomycorrhizal (intercellular) or endomycorrhizal (intracellular), depending on where the fungus is located in the plant. Ectomycorrhizae are usually produced by the interaction of forest tree roots with either basidiomycete (that is, mushrooms or puffballs) or ascomycete (that is, mold) fungi (Deacon 2006). Primarily, ectomycorrhizae are located on the feeder roots of woody plants. These roots are devoid of root hairs, making the presence of the fungus crucial for increasing the functional surface area of the plant root. Nutrient uptake is further enhanced by the expansion of the mycorrhizae into the surrounding soil and the subsequent transport of water, nitrogen, and minerals through the fungus to the plant root (Deacon 2006).

Ectomycorrhizal fungi typically form mycelial cords to aid in soil penetration and form a network of hyphae in the soil. Individual plants are linked to each other by this network of hyphae, allowing nutrients to move between plants (Deacon 2006). Additionally, the presence of this hyphal web facilitates the turnover of nutrients from plant rootlets, up to 90% of which are replaced each year (Deacon 2006). Without this reclamation system in place, the nutrients stored in these rootlets would likely be lost, leading to a steady decline in available carbon and nitrogen for plant growth.

Endomycorrhizae are the more well-known and studied type of mycorrhizal interaction and are more cosmopolitan in distribution than ectomycorrhizae (Deacon 2006). In contrast to ectomycorrhizae, endomycorrhizae are primarily formed by zygomycete fungi. Arbuscular mycorrhizal (AM) fungi are another name for endomycorrhizae. This is because they make arbuscles, which are special structures for feeding, in the space between the root cortical cells’ cell membrane and cell wall (Deacon 2006; Hennigan 2009).

Arbuscles allow for effective nutrient exchange between the fungus and the plant because the fungus does not kill the cells that are home to the arbuscles. Current secular understanding of the development of fungi is based on fossilized AM fungi found in Ordovician and Devonian strata and dated to ~460–354 million years ago. It is interesting that these ancient AM look a lot like modern AM and have not changed in the time frame of evolution that has been suggested (Remy et al. 1994), which makes it hard to believe that they evolved through materialistic processes over millions of years.

The role of AM fungi within a creation framework has been recently explored (Hennigan 2009). Much like the ectomycorrhizae, AM fungi form networks of hyphae in the soil and facilitate the exchange of nutrients between individual plants (Smith, Read, and Harley 1997). These networks assist in establishing plants in soil and may have enhanced plant re-colonization of land after the Flood recorded in Genesis 7 and 8. AM fungi in particular may have played a bigger role than the ectomycorrhizae in this due to their expanded host range. Regardless, mycorrhizae may constitute an originally created mutualism that allows plants to grow optimally in all types of soils (Agrios, 2005).

Conversely, mycorrhizae may have been originally created to restrict plants to particular ecological niches. Using various dune-inhabiting species of plants, Francis and Read demonstrated the differential response of these plants to AM fungi, with Plantago lanceolata showing enhanced growth and the mycorrhizae and other species showing repressed growth (Francis and Read 1995). This study built on Grubb’s work, who discovered that in the chalk grassland ecosystem in Great Britain, there were four different groups of annuals and biennials. There was not much mixing between the populations of groups B, C, and D (plants that only grow in open areas that get disturbed often) and group A (plants that grow in closed turf habitats) (Grubb 1976).

Francis and Read (1995) suggest that the reason certain species are unable to colonize exposed soil in these closed ecosystems is due to the presence of AM fungi. It is also interesting that many agriculturally important weed species are not mycorrhizal and are inhibited by the presence of mycorrhizae when trying to invade so-called “closed” plant communities (Francis and Read 1994). It is possible that the loss of mycorrhizal associations by these plants is part of the original Curse (Genesis 3:17–18), and may be part of the reason these weed species devolved from their original created state.

Endophytes

Commensal fungal interactions with plants are not restricted to the roots. Within the last hundred years, endophytic fungi have been described that reside in plant tissues yet do not cause disease (Carroll 1988). Similar to the ectomycorrhizae, endophytic fungi are primarily ascomycetes, with a few basidiomycete endophytic fungi identified (Rodriguez and Redman 2008). In contrast to the mycorrhizae, endophytes seem to be important in stress tolerance and enhancing plant biomass (Rodriguez and Redman 2008) and may therefore work in concert with mycorrhizae for optimal plant growth.

Recent work has revealed the importance of endophytic fungi in salt- and heat-stress tolerance (Rodriguez et al. 2008). In their study, Rodriguez and colleagues showed that endophytes isolated from dunegrass were able to colonize both panic grass (representative monocot) and tomato (representative eudicot). Endophytes are interesting because they only give grasses in certain ecological niches resistance to the stresses that are specific to those niches. For example, coastal grasses can handle salt stress, geothermal soil grasses can handle heat stress, and agricultural grasses can handle disease and drought stress (Rodriguez et al. 2008).

The complexity of these interactions is greater than was initially anticipated; a three-way symbiosis necessary for thermal tolerance in geothermal soils has been recently described (Marquez et al. 2007). In this interaction, the researchers demonstrated that heat tolerance induced by the endophyte in panic grass was dependent on the presence of a fungal virus. Plants with virus-free endophytes were susceptible to killing at 65°C, whereas plants with virus-infected endophytes could survive at that temperature. Tomatoes became more resistant to heat after being infected with the virus-containing endophyte. This shows how widespread these higher-order interactions are and suggests that they were probably present during Creation Week. Indeed, these symbioses appear to have been designed to enable re-colonization of the varied soil types found in the post-Flood world.

Lichens

Fungal symbiotic/commensal relationships are not restricted to multicellular plants. A famous example of this is the lichen. Lichens are symbiotic partnerships between fungi and photosynthetic microbes, such as algae or cyanobacteria (Deacon 2006). In this relationship, the fungus (mycobiont) provides a physical structure in which the photosynthetic partner (photobiont) resides, and the photobiont provides the mycobiont with energy via carbon fixation (Deacon 2006; Webster and Weber 2007).

There are an estimated 18,000 species of lichens and ~98% of these associations involve ascomycete fungi; the remaining lichens involve basidiomycetes (Webster and Weber 2007). As seen above with other symbiotic associations, lichens show an increased resistance to desiccation and other stresses and therefore are found in regions inhospitable to vascular plants (Webster and Weber 2007). These peculiar organisms are present in all ecological zones and can even colonize bare rock. Some lichens exhibit an extremely slow growth rate and certain individual lichen colonies have been estimated to be over 1,000 years old (Karlen and Black 2002).

Lichens demonstrate the potential for plasticity of higher-order interactions between phyla. Often, geographically limited communities of lichens with disparate mycobiont members share a single or few photobiont partners (Webster and Weber 2007). In fact, some lichen species have been shown to “steal” photobiont partners from other lichens (Honegger 1993). Different photobiont species will generally provide the mycobiont with different carbohydrates: cyanobacteria provide glucose, whereas green algae provide polyols, which are alcohols of various sizes with multiple hydroxyl groups. (Webster and Weber, 2007).

Lichens pose a dilemma for Darwinian evolution. The advantage of the symbiosis to the mycobiont is obvious (steady carbohydrate source), but the advantage to the photobiont partner is unclear. The photobiont probably has an evolutionary advantage because the mycobiont protects the growth of the photosynthetic partner. This supports the idea that lichens were the first plants to colonize land before vascular plants (Webster and Weber 2007). Further supporting this scenario are molecular clock data indicating that lichen symbioses arose before vascular plants approximately 1 billion years ago, according to the Darwinian paradigm (Heckman et al. 2001). On the other hand, fossils support the traditional evolutionary view that spore-producing plants (liverworts, mosses, etc.) first settled on land about 475 million years ago, during the Ordovician age, according to the evolutionary geologic timescale (Campbell 1990; Wellman, Osterloff, and Mohiuddin 2003).

Interestingly, the appearance of plant spores in Ordovician strata parallels the appearance of fungi in the same strata (Redecker, Kodner, and Graham 2000; Wellman, Osterloff, and Mohiuddin 2003). Evolutionary presuppositions influence both of these hypotheses. In the biblical creation paradigm, all of these organisms were present from the beginning. The biblical creation view of the geologic column construes these layers as representative of different ecological zones and their order of burial during the Flood and its aftermath (Woodmorappe 2000). Therefore, geologic evidence supports the hypothesis that fungi and plants inhabited the same ecological zones, and that the land was colonized by both lichens and vascular plants from the beginning.

Furthermore, lichens pose a serious challenge for evolution due to the intricate nature of the interaction between the mycobiont and photobiont partners. The interaction of both partners is recalcitrant to selection, as the putative ancestors of both mycobiont and photobiont species would have been free-living. If there was selective pressure to move from the relatively mild conditions of ocean habitats to the harsh conditions of rock faces through symbiosis, it would have had to go against the partner species’ stable free-living way of life. Considering that fossils from the Devonian period show a lichen symbiosis that is almost identical to lichens that grow today (Taylor et al. 1995), it is very unlikely that this symbiosis formed by chance. Therefore, lichen symbioses attest to being designed, and explicitly demonstrate creation’s obedience to God’s command to “fill the earth” (Genesis 9:1).

Fungal Associations with Animals

In contrast to the Plant Kingdom, fewer commensal associations have been described between fungi and animals. For example, certain species of termites, ants, wasps, and beetles are the only known insect species in symbiotic interactions with fungi (Deacon 2006). In the ant, beetle, and termite symbioses, the insects grow the fungi for food (Aanen and Boomsma 2006; Deacon 2006). Wood wasps use fungi for a slightly different purpose: to “pre-digest” wood in dead or dying trees for consumption by the wasp larvae (Deacon 2006).

From the evolutionary perspective, these insects utilize fungi in order to make use of the available cellulose found in plants (Deacon 2006). These symbioses are believed to be highly evolved, as the fungus-insect interactions are mostly specific between insect and fungal taxa (Mueller and Gerardo 2002; Mueller and Rabeling 2008). Recent work focusing on the timeline of ant-fungus mutualism proposes that the oldest type of interaction involves fungi that are capable of saprophytic growth (that is, free of the ant symbiont), with interactions involving obligate mutualism such as the leaf-cutter ant symbiosis being a recent development (Schultz and Brady 2008).

The biblical worldview differs from the evolutionary worldview mainly in regard to the origins and timescale of the development of these symbiotic interactions. Based on the phylogeny of the insect species that use these interactions, it seems likely that “agricultural” insects like attine ants came from separate baramins, with one baramin for each agricultural ant and termite family (Mueller and Gerardo 2002). Presumably, these insects were originally designed to use leaf litter as compost for growing fungi, with recent corruption of this purpose resulting in the destruction of living plant tissue (Mueller and Rabeling 2008).

The beetle-fungus and wood-wasp mutualisms seem to have been created for different purposes. These mutualisms take advantage of dead or damaged trees and may have been originally created to exploit nutrient recycling in complete their life cycles. These symbioses have also been corrupted since the Fall, resulting in damage to living trees and causing significant economic loss (Anonymous 2006, 2009).

Higher animals (that is, Bilateria—the group of eumetazoan animals having bilateral symmetry) have also been shown to share commensal relationships with fungi, although there are relatively few examples. Various “primitive” fungi are known to inhabit the gastrointestinal tract of various herbivores and aid in the digestion of plant matter (Akin and Borneman 1990; Wubah, Akin, and Borneman 1993). Some fungi, mostly those in the phylum Chytridiomycota, release enzymes that break down tough plant polymers like xylan, hemicellulose, and cellulose (Wubah, Akin, and Borneman 1993).

Given that all animals were herbivorous in the original creation (Genesis 1:29–30), we can infer that these kinds of commensal fungi were likely present in the GI tracts of most, if not all, animals. The change in diet after the Flood (Genesis 9:2–4) likely resulted in an alteration in the microflora of certain animal species so that they could not digest vegetation efficiently and therefore became carnivorous.

Effects of the Curse

As a result of man’s rebellion, God allowed man to see what the world is like without His sustaining power maintaining all the interconnected relationships He had created. This allowed these relationships to degenerate to varying degrees, as typified by the rise of pathogenic relationships between various microbes and vascular plants, animals, and humans. It is interesting that of the estimated 1.5 million fungi, only slightly more than 10,000 (<1%) cause diseases of plants and animals (Agrios 2005; Deacon 2006). This stands in stark contrast to the materialistic view that pathogenic fungi have evolved to parasitize plants and animals over the last ~400 million years.

Since Darwinian evolution supposes random mutations with subsequent selection, it seems reasonable to expect that significantly more than 1% of fungi would parasitize other organisms. This discrepancy could be attributed to the defense mechanisms of higher organisms, although that reasoning would presuppose the evolution of defense mechanisms against threats that had yet to exist. It is far more likely that plant and animal defense mechanisms were originally designed to allow efficient interaction between host and microbe in a mutualistic interaction and only became “defensive” in nature once these interactions degenerated.

Plant Pathogens

While many commensal and symbiotic relationships exist between fungi and plants, there are a number of detrimental associations involving fungal parasites and pathogens. In the evolutionary worldview, plant disease-causing fungi evolved pathogenicity as a lifestyle over the last few million years during their coexistence with plants. The current view is one of an arms race: pathogens evolve mechanisms to use plants for nutrition and reproduction, and plants likewise evolve mechanisms to resist or evade them. This is in stark contrast to the biblical creation worldview, where plant diseases are the result of the curse by God on the whole of creation due to man’s sin (Genesis 3:17–18). In this worldview, pathogenicity is the result of the corruption of the originally designed commensal and symbiotic interactions between plants and microorganisms (such as fungi). A proper understanding of how pathogenicity arose will enable us to develop better strategies for intervention.

The current data supporting Flor’s gene-for-gene hypothesis as well as our current understanding of the establishment of basic compatibility between host and pathogen are consistent with a Modification/ Displacement Model of disease origins (Flor 1946; Purdom and Francis 2008). Under this model, microbes were initially created with particular functions necessary for the maintenance of life on earth. Their presence was restricted to particular niches where they functioned according to the original design. Following the Fall, the Curse brought about the modification of certain biochemical compounds and cellular structures, which have since become the focus of disease research (that is, toxins, invasion structures, etc.). The first mention of disease in the Bible does not occur until after the Flood account, during Job’s temptation by Satan (Job 2:6–8). Perhaps the Flood caused massive displacement of microbes from their initial habitats through the complete destruction and remodeling of the earth’s surface, which led to the introduction of these microbes into new ecological niches including plants, animals, and humans.

There are basically two types of plant pathogens (Agrios 2005): obligate pathogens (that is, biotrophs) and facultative pathogens (that is, hemibiotrophs and necrotrophs). Biotrophic fungi require living plant tissue as a substrate, where they complete their entire life cycle. In contrast, hemibiotrophic and necrotrophic fungi complete at least part of their life cycles on dead plant tissue. A cursory comparison of plant pathogenic fungi and plant symbiotic fungi reveals that in many cases, both pathogens and non-pathogens utilize similar (if not identical) structures for associating with their plant host. For example, both AM fungi and powdery mildews utilize haustoria for nutrient acquisition from plants. The major difference between these two interactions is that the AM fungi reciprocate nutrient exchange with their host, whereas the powdery mildew exploits its host for nutrition.

A more pointed example of the degeneration of these interactions comes from endophytic fungi. Carroll defended the evolution of endophytic fungi from plant pathogens on three points: 1) endophytes can cause pathogenic symptoms during plant stress; 2) some crop pathogens live commensally with weeds growing among the crop host; 3) some pathogens are sister species of endophytic fungi on the same or related hosts (Carroll 1988). However, this hypothesis on the development of endophytic relationships presupposes Darwinian evolution to be true. These data also support the biblically-based hypothesis that endophytes were originally created to live symbiotically with plants and that certain pathogenic relationships developed via the degeneration of these highly coordinated interactions. Lack of proper controlled growth in the host can lead to the development of pathogenicity in a commensal or mutualistic state.

A single-gene mutation in the grass endophyte Epichloë festucae changes the interaction of this fungus and its host from a mutualistic to parasitic interaction and results in, among other things, uncontrolled growth of the fungus (Tanaka et al. 2006). It is also clear that inbred crop species do not have the same signaling and recognition genes as their wild “weed” relatives. These genes are needed to protect against pathogens (Agrios 2005), which is why pathogens can live inside these related species. So, the biblical model of creation is strong and can explain how plant pathogens evolved from fungal species that feed on plants or that live together and help each other.

Animal Pathogens

Of the fungi that cause diseases in higher eukaryotes, only about 200 have been shown to cause disease in animals. This is likely reflective of the overall lower number of mutualistic interactions in which these organisms participate. Many of the mycoses studied to date involve humans as terminal hosts, with underlying immune impairment being chiefly responsible for host susceptibility (McNeil et al. 2001). A lot of the important fungal genera that cause disease, like Aspergillus, Penicillium, Blastomyces, Histoplasma, Coccidioides, and Cryptococcus, probably stay in the environment as saprophytic fungi (Heitman 2006). There are three interesting exceptions: Candida albicans, Pneumocystis spp., and the dermatophytic fungi. These three groups of fungi are host-acquired, and in the case of Pneumocystis, infection only occurs in another infected host. Candida and Pneumocystis pathogenic relationships are described in more detail below.

C. albicans is a commensal yeast of humans and warm-blooded animals that normally resides on skin and mucosal surfaces (Deacon 2006). This yeast that lives with humans is used as a model human fungal pathogen to study phenotypic switching. This is the process by which a fungus grows as one morphotype (like yeast or hyphae) when it is a commensal and then changes to the other morphotype when it is a pathogenic. In the case of C. albicans, the commensal form is primarily yeast and the hyphal form is important for tissue invasion. Certain host factors, such as body temperature, regulate this change in morphology (Webster and Weber 2007).

Recently, the genome sequences of eight different species of Candida were compared to try to figure out how these fungi became pathogenic and reproduced sexually (Butler et al. 2009). The authors found that expansion of certain gene families, presumably by gene duplication, was present in the pathogenic species of Candida. These proteins are important in adhesion to epithelial cells and therefore pathogenicity, but they also play an important role in biofilm formation (Bennett 2009). Similar observations were made for other cell-wall protein families in Candida (Butler et al. 2009). Bennett proposed that these gene families, which display high mutation rates, “provide . . . a selective advantage for invasion and infection of the mammalian host.” (Bennett 2009).

This statement suggests a Darwinian view that pathogenic relationships are a kind of “advancement” in the development of a species. Instead, these results support the biblical view of creation that pathogenic interactions are a decline from the originally created mutualistic and commensal interactions that happened when ancestral types (that is, baramin) were changed. These modifications resulting in pathogenesis include mechanisms such as gene family expansion, point mutations, and genome rearrangements (Butler et al., 2009; Morschhäuser et al., 2000). Interestingly, a biblical creation model describing a mechanism for rapid diversification within created kinds via Altruistic Genetic Elements (AGE) has been proposed that involves genomic rearrangements, DNA transposition, and horizontal gene transfer (Wood 2003).

Pneumocystis is a fascinating genus of fungi that is quite different from the other animal pathogenic fungi mentioned so far. Species of Pneumocystis have been found in the lungs of a wide assortment of mammals (Deacon 2006), yet there is a pronounced host specificity for each Pneumocystis species (Wakefield 2002). As a group, Pneumocystis is obligately commensal and recalcitrant to growth under laboratory conditions (Heitman 2006). These properties make research on the ecology and host-pathogen interaction difficult. Unlike the other fungal pathogens of humans, Pneumocystis appears to be transmissible between hosts (Heitman 2006) and uses cholesterol instead of ergosterol as its main membrane sterol (Webster and Weber 2007).

The unique properties of Pneumocystis make a materialistic explanation of their origin difficult. They are believed to be relatively ancient fungi, taxonomically near the branch point between Ascomycetes and Basidiomycetes (James et al. 2006). Over time, they have formed a strong commensal relationship with their host, to the point that individual species of Pneumocystis are host-restricted and only associate with a particular species of host. Generally speaking, the Darwinian view of commensal evolution consists of the co-evolution of two (or more) species over many generations, with adaptation of the symbiont from parasite to commensal to mutualist (Ewald 1987). According to this model, Pneumocystis probably first interacted with mammals as an environmental parasite. Over time, it changed into an apparent commensal, only infecting animals when their immune systems were weak (Heitman 2006).

However, this materialistic explanation does not provide a satisfying account for their origins, especially in light of their obligate lifestyle. For example, Pneumocystis has never been isolated from the environment, and no extant examples of closely related fungi exist; Pneumocystis is classified as an Ascomycete, but all members of this genera belong to a unique taxonomic class, Order, and Family (Heitman 2006; Thomas and Limper 2007; Webster and Weber 2007). Also, different Pneumocystis species have been shown to be very host-specific, meaning that each species is only found on a certain type of mammal (Gigliotti et al. 1993).

From a Darwinian perspective, this implies that the Pneumocystis-mammal interaction formed immediately after the supposed split of the mammalian lineage from the Tree of Life. This seems highly unlikely given the lack of environmental isolates or any closely related species as symbionts of other animal taxa. Indeed, the biggest impediment to establishment of a symbiotic relationship is overcoming host immunity, which would likely require numerous attempts (Doebeli and Knowlton 1998).

From a biblical creation perspective, it may be that Pneumocystis spp. were originally designed to exist with mammals, much like endophytic and mycorrhizal fungi exist with plants. Recently, it was noticed that Pneumocystis colonization may protect against virus infection (Cavallini Sanches et al. 2006). This is a general effect that has been seen in other situations, such as with plant-associated fungi (Agrios 2005; Barton et al. 2007; Oliver et al. 2009; Rodriguez et al. 2008). This would explain why Pneumocystis does not hurt immunocompetent hosts. Their original job would have been to boost the immune system in the respiratory tract and/or take up spaces in the respiratory epithelium to stop other microbes from getting in. More research needs to be done to explore their possible role in healthy hosts in light of the biblical creation paradigm so that diseases caused by these microbes can be properly understood.