Case Study: Microbiome's Impact on Adaptation and Evolution BVB305

This case study delves into the multifaceted role of the microbiome in biological systems, ecological interactions, and evolutionary processes. The paper begins by introducing the concept of microbes and their prevalence on multicellular organisms, highlighting their significance in both hindering and facilitating biological and technological advancements. The study explores the microbiome's influence on host biology, ecology, and evolution, emphasizing the mechanisms of transmission and the concept of holobionts. The discussion covers the manipulation of microbial genomes to reduce disease prevalence and the role of microbes in environmental protection, agriculture, and the development of sustainable solutions, such as the use of Bacillus thuringiensis and baculoviruses. The paper concludes by summarizing the importance of the microbiome in various fields and its essential role in the evolution and development of organisms, with a focus on its applications in agricultural development and human protection.

Running head: THE MICROBIOME, ADAPTATION AND EVOLUTION
The microbiome, adaptation and evolution
Name of the Student:
Name of the University:
Author note:

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THE MICROBIOME, ADAPTATION AND EVOLUTION
Introduction:
Over the thousand years, microbes are using plants and animals as shelter to replicate and
retain ancestors (Rosenberg, E., & Zilber-Rosenberg, 2016). The microbes are present in large
number on the surface of a multicellular organism which includes plant, animals and human
being. While microbes have potentials to hinder normal growth of other organisms, they are the
key players behind decade biological and technological evolution. Without the microorganism,
plants, animal, even human would not be able to survive and evolve (Fitzpatrick et al., 2018).
The purpose of the paper is to explore the function of the microbiome in biology, ecology, and
evolution of their host, specifically how these functions used for improving technology in
environmental protection, agriculture. This paper will illustrates the function of the microbiome
in biological, the ecological function of hosts, influence of these process on plant and animals,
how the microbiome can be used in environmental protection, cities, and agriculture.
Description:
Microbes are abundant in a large number of surfaces of multicellular organisms such
plants and animals where the high prevalence is observed in skin, digestive system, airway and
also inside some plant by the process of endosymbiosis. As discussed by Yeoh et al. (2016),
approximately 108 bacteria are present in leaves and in the rhizosphere, the number of bacteria is
twice of leaf and 106 fungi per soil are being attached to the epidermis of roots. The researchers
documented that a large number of these microbes associated with the different host through the
process of symbiosis which further give rise to the holobionts (Theis et al., 2017). These
microbes not only take part in the development of disease but also take part in the evolution of
the species. Hence, the abundance of disease by microbes can be reduced by manipulation of the

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genome. Approximately, 1014 microbes are present in the digestive tract of animals which
enhances the morphological and immunological development, fibrinolysis activity, functioning
fermentation of microbes and pathogen resistance (Shapira, 2016). The ruminant microbes
include proteobacteria, methanogen archea, anaerobic fungi, and virus are present that enhances
the process discussed above. Considering the plant system, Rhizobium, Agrobacterium
tumescence, Frankie, Bacillus thuringiensis, Bacillus cereus, mycorrhizae certain virus such
as tobacco mosaic virus are normal flora of plants which enhances the activity such improving
quality of soil , improving water retention capability and protects from insects (Hardoim et al.,
2016). Hence, although these microbes are considered as tiny entities, they contribute to the
fitness of the holobionts and to its adaption as well as evolution by changing different processes
(Beasley et al. 2015). However, while these microbes are able to induce diseases, they can be
manipulated for the wellbeing of mankind.
Discussion:
How microbes influence the biology, ecology, and evolution of their hosts:
For micro biotas to influence the evolution, normal biological function and adaptation of
their hosts such as plants and animals, these microbes must be transmitted to generation to
generation. As discussed by Groussin et al. (2017), to take part in the evolution process, host
genome along with symbiotic genome is required to transmit from one generation to another
generation with the assistance of an array process such as cytoplasmic inheritance ,
consumption of feces, during direct contact , through vectors, vegetative reproduction.
Relevant, in this case, are microbes and hosts as well as vectors. The vegetative reproduction is
the means by which microbes can automatically transfer to the offspring (Hammer et al., 2017).

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Ancient apes have retained many microbes through vertical transmission over evolution scale,
especially helicobacterium pylori which act as a marker for ancestry as well as migration.
Usually, the normal flora of the animals and plants which are present relatively in large numbers,
do not causes potential disease rather they take part in the evolution process. The non-core
microbes which are transient in nature and dependent on the environmental conditions can
induce disease because of the multiplication and have potentials to abolish a generation (acquard
et al., 2017). Sometimes, they become stable inhabitants of holobionts and become an integrated
part of core microbiota. This microbial genome can be manipulated genetically in order to reduce
the prevalence of the disease. Hence, these microbes can play a crucial part in evolution. While
considering the concept of hologenome, it is crucial to underpin the theory of hologenome which
recasts the individual animal and plant as a community or holobionts (hosts and symbiotic
microbes) (Vandenkoornhuyse et al., 2015) .The hologenome theory of evolution is unique and
numerous research support this theory of evolution. This theory suggested that all microbes and
their host interact in such as a way that influences the adaptation which includes behavior,
morphology, resistance to disease, development (Clayton et al., 2016). Hence, these microbes
and their interaction are the key factors behind the unique evolution of holobionts as well as
abolish of species because of their ability to adapt to the environment and surroundings. As
discussed above, in order to attenuate the disease-causing genes of microbes it is crucial to bring
the changes in not only the host gene but also in microbial genes.
Considering the plant system, Microbiota is a crucial part of the evolution of plants
where mitochondria and chloroplasts are considered as extreme symbionts as they were derived
from cyanobacteria and alpha-proteobacteria. While mitochondria are the energy house of all
multicellular organisms, chloroplasts are responsible for photosynthesis, immune responses in

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plants, lipid metabolism. Ripari, Gänzle and Berardi (2016), reported that a significant number
of microbes contributed to the biological and physiological processes of the plant. For example,
considering the nitrogen fixation by leguminous plants is conducted in presence rhizobium which
is a diazotrophic bacteria (Berg et al., 2015). This rhizobium takes part in nitrogen fixation after
invading root nodules of legumes and expresses the nitrogen fixation gene such as nod genes.
Another example of fitness and evolution is mycorrhiza which is defined as the symbiotic
association between fungus and plants (Gopal & Gupta, 2016). Mycorrhiza can be intracellular
and extracellular. In both types of association, the plants provides molecular sugar and other
metals which were produced because of photosynthesis and in return fungus supplies to the
plants and water as well as mineral nutrients such as nickel, phosphorus from the soil (Cúcio et
al., 2016). This symbiotic association not only favors the supplies of the nutrients and water but
also the association protects roots from the pathogens. These microbes induce metabolic
changes in the plants for promoting the storage of fats tissues and another essential energy
precursor. While microorganism can facilitate evolution, bacteria like Bacillus thuringeinsis are
able to reduce the diversity of insects through producing toxins.
Considering the animal kingdoms, the microbes also can take part in the evolution of
animals. The very first example of symbiosis in the animal kingdom which enhances the
biological process and evolution is the symbiosis between gut microbes and ruminants. The
ruminants require 70% of the energy in ruminants to conduct normal biological process and
these microbes acquire these energies from the fermentation process (Christian, Whitaker &
Clay, 2015). The cellulose cannot be degraded by human because of the absence of cellulase
enzyme. In ruminants, the cellulose-containing bacteria easily digest cellulose where termites are
used as vectors for these microbes. The microbes take part in the remaining metabolism by

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converting acetate to fatty acids and providing the supply of proteins for nitrogen metabolism
(Kundu et al., 2017). The ruminant’s microbiota helps in toxin degradation, increase pathogens
and maturation of the human system and endocrine system. In animal, the microbial produced
chemical signal is crucial for the development of organs (Dua et al., 2017). The endosymbiosis
of Wolbachia produces signals which prevent the apoptosis of ovaries wasp host. The vibrio
fisher is responsible for the development of light organs in squids and any other bioluminescent
(Busby et al., 2016). Most of the researchers highlighted that gut microbes are directly associated
with the development of cognitive behavior and brain. In Drosophila melanogaster, sexual
behaviors are influenced by Lactobacillus plantarum (Busby et al., 2016). Hence, this evidence
supports the hologenome theory of evolutions and contribution to adaptation. While microbes
can influence positive development, organisms such as Bacillus anthrasis can cause disease in
cattle’s when cattle swallow the spores of anthrasis. Hence, in order to attenuate the disease-
causing characteristics of microorganism, changing in the genetic variation is required.
The process of using microbes for environment protection and agriculture:
As discussed before, the microorganism of the plants and animal plays a huge role in the
evolution and development of an organism. While core microorganisms are the part of the skin
and gut of animals and leaves, the root of plants and take part in evolution, some microbes
through their symbiosis process cause potential disease. Bacillus thuringeinsis is a vital example
of this disease-causing of characteristics of microbes which can abolish the existence of other
organisms such as insects (Busby et al., 2016). Bacillus thuringeinsis is naturally gram-positive
soil bacteria, which produces bt toxins which have capabilities to inhibit the growth significant
number of insects (Colston, & Jackson, 2016). Bt toxins produced by Bacillus can be used
potential insecticides since it binds to the specific receptor in gut and insects stops eating. This

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organic insecticides not only inhibit the diversity of pests but also increase crop production by
40%. Bt cotton is another example of resolving the issue and using the negative trait of
microbes in the betterment of mankind. Bt cotton is genetically modified pest-resistant plant
which were designed for combatting the bollworm by altering the cotton genome of microbial
protein. The baculovirus can be another virus used for the growth of crops and enhances
agriculture. It is a virus having occluded, circular dsDNA, occlusion body which is specific to
invertebrates. Baculovirus is another virus and member of microbiome which attacks insects and
other arthropods. This virus can be used in agriculture as a pesticide in order to enhance
agriculture. There are certain microbes which are transients and attached to the roots and leaves
to colonize and destroy plants. In order to reduce microbial diversity, it is crucial to implement
strategies that would be effective in facilitating agriculture. The researchers suggested that
Colonization of the rhizosphere by entomopathogenic fungi can protect plants from pathogenic
microbes which further enhance the yield. Trichoderma spp. is another microbe which helps to
combat the pathogenic microbes of plants with the assistance of process such as antibiosis,
competition, and parasitism. Nitrifying rhizobia in roots is another crucial strategy which acts as
a potential biopesticide (Rosenberg, E., & Zilber-Rosenberg, 2016).
Considering animal kingdom, the gut microorganism of ruminants is crucial for animal
and productivity since it can enhance economic performance; protect the environment and
mankind through manipulation (Busby et al., 2016). Over the past decades, the United States
is using microorganisms of animals for combatting disease. For examples, in order to combat
the disease caused by opportunities pathogens such as E.coli and salmonella, gut microbes such
as Lactobacillus acidophilus can be used for producing probiotics. 30 formulations of probiotic
are approved in Australia and 100 organisms registered in Europe (Colston, & Jackson, 2016).

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Bacillus subtilis can be provided to the broiler’s chicken who are suffering from necrotic enteritis
by C. perfringens. It was proved to improve intestinal health. Therefore, microorganisms in
symbiosis with the host cells facilitate the process of evolution and development of mankind.
Conclusion:
Thus it can be concluded that microbial communities which live on plant surface and
animal and play a crucial role in the evolution and development of these microbes. While
microorganisms are used in many different fields to bring evolution, without doubt, microbes are
used extensively in agricultural development and human protections. Microbes are abundant in a
large number of surfaces of multicellular organisms such plants and animals where the high
prevalence is observed in skin, digestive system, airway and also inside some plant by the
process of endosymbiosis. Through the symbiosis, microbes change the physiological and
biological process which helps plants and animals to adapt to the environment. This paper
explored examples such as Rhizobium, ruminant gut microbes, Trichoderma, mycorrhiza.
However, these microbes can have potentials to destroy animal and plant kingdom. In order to
retain these kingdoms and contribute to the development of mankind, these microbes can be
used as bio-pesticides, transgenic cotton, and probiotics. Therefore, from the above discussion, it
can be stated that the animals, plants and microbes are all intertwined with each other and there
is clear link and dependency on each other. In the discussion above, it can be seen that the
microbes can cause harmful and fatal disease on the animals and plants as well as they are
responsible for the aspects like plant and animal evolution. Hence, in a concluding remark, it can
be stated that the animals and plants can no longer be considered as single individual and each of
them are holobionts with numerous host and symbiotic microbes.

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Recommendation:
It has been well established and evidenced in the above section is that microbes are really
beneficial and can be utilized in various aspect of animal and plant life. There are literally
innumerable number of microbes present in the ecology of life which has both harmful and
beneficial effect. Beneficial effect can only utilized by human kind if proper mechanism and
their role in the concept of holobionts can be understood properly. Therefore, primary
recommendation will be thorough and extensive analysis of the role of microbes with regard to
their beneficial activities. Hence, further research widespread investigation is required in this
area so that the role of the microbes can be understood properly for the better utilization of the
beneficial aspects.

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