The concept of ecological services
The concept of ecological services is defined as the ways organisms and human beings use the environment in order to provide for themselves and the environment. There are different types of ecological services that can be discussed. These services include purification of water and air, maintenance of biodiversity, vegetation and soil regeneration or renewal, decomposition of wastes, and pollution water (Ecological Society of America, 2003, p. 87).
According to the Ecological Society of America (2003, p. 100-128), ecological services provide the means to offer better service to both human beings and animals. Ecological services can be described in simple terms as:
Offering natural resources for basic survival such as clean air and water
A contribution to good mental and physical health through access to green places as well as genetic resources
Natural processes such as crop pollination and climate regulation
Maintain of a strong and robust economy through raw materials, and
Support of social, educational and cultural gains originating from interaction with nature
Therefore, ecological services offer both human beings and animals anthropogenic value, for instance: the process of pollination in plants and water filtration help to enhance the quality of both human beings and animals through supporting strong health.
The services provided by ecological services to both animals and human beings can be classified into three groups such as provisioning services, regulatory services, and cultural services. Provisioning services entails services such as food, fresh water, fiber, biochemicals, and genetic resources. Regulatory services include climate regulation, pollination, water purification, water regulation, and disease regulation. Cultural services include services such as spiritual and religious services, recreational and ecotourism services, aesthetic services, inspirational services, sense of place and educational services, and cultural heritage (Todd, 2005, p. 25-45).
Ecological services of rivers
From the Mini Lecture, two services of rivers that are most important include agricultural and drinking services. Water from rivers is mostly used for agricultural services, which as a result contributes to pollution and contamination because of excess use of nutrients, pesticides, and other forms of pollutants. Sustainable use of water in agriculture for irrigation services becomes highly critical in order to ensure and maintain both environmental and social benefits. Water from rivers for irrigational services ensure a stable supply of farm or agricultural produce for both human and animals consumption. In addition, water is used for drinking for animals and human beings, which is a very important aspect. Animals and human beings require water for metabolic processes. Without water animals, plants, and human bodies will stop working properly (59). This is because more than half of these organism’s bodies comprise of fluids and depend on water.
Two of the services that are likely to decline due to human influence include waste disposal and energy services. The ecological services of water in waste disposal are likely to decline because of the influences of human beings. Waste products can be recycled and disposed without the use of water due to the advancement of technology. The use of water in waste disposal leads to pollution and contamination of water systems. Thus, with improved technology, human beings will made tremendous progress in sustaining water resources by ensuring that alternative waste disposal methods are used. Moreover, use of water in energy production is also likely to decline due to availability of alternative energy production techniques. Solar energy, for instance, provide a highly viable and alternative method of energy generation in the world today (96).
Ecological Society of America. (2003). Frontiers in ecology and the environment. Washington, DC: Ecological Society of America.
Todd, N. J. (2005). A safe and sustainable world: The promise of ecological design. Washington, D.C: Island Press.
ECOLOGICAL SERVICES 4
Running head: ECOLOGICAL SERVICES 1
Is Interspecific Competition behind the Decline in the Number of Cheetahs?
Interspecific competition leads to limiting the resource(s) whose availability influences survival or reproduction of the species involved. This kind of competition may take place in the form of interference or exploitation. In interference, species directly clash with each other for the resource. In contrast, exploitation is an indirect form where species compete by exploiting the resource and thus leaving little available for their competitors (Begon et al., 1996).
This study will involve cheetahs and lions, which feed on similar prey. If all of them consume the prey, they will have little food. Competition between them has a great influence on their evolution, structuring and distribution.
The Lotka-Volterra model is a mathematical representation that will be used to investigate the relationship between factors that affect the outcomes of competitive interactions. The results of this model can also give insights into intraspecific competition. This model seeks to answer two fundamental questions, which are, the circumstances under which two species can coexist and the circumstances under which one species outcompetes the other (Soetaert & Herman, 2009).
The variables to be used in this study are: population size (N), time (t), carrying capacity (K), intrinsic rate of increase (r) and competition coefficient (a).
Sample population 1 (cheetahs)
Sample population 2 (lions)
The competition coefficient represents the effect one species has on the other such that a12 is representing the effect of the lions on the cheetahs and a21 representing the effect of cheetahs on the lions. The results of a12 will be compared with the results of a21. This study hypothesized that the prey species were strongly limited by territory. The study will be a field trial and will run for a span of 3 months. The factor that will be manipulated is the geographical area. It will be assumed that the prey is most concentrated in the leafy grasslands (Gittleman & Zoological Society, 2001).
Begon, M., Harper J., and Townsend, C. (1996). Ecology: Individuals, Populations, and Communities, 3rd edition. Blackwell Science Ltd. Cambridge, MA.
Gittleman, L., & Zoological Society. (2001). Carnivore conservation. Cambridge: Cambridge Univ. Press.
Soetaert, K., & Herman, J. (2009). A practical guide to ecological modelling: Using R as a simulation platform. Dordrecht: Springer.
INTERSPECIFIC COMPETITION 4
Running head: INTERSPECIFIC COMPETITION 1
Terrestrial and Aquatic Ecosystems
An ecosystem is comprised of a community of different species that are interacting with one another and with the chemical and physical factors that makes up its non-living environment. Ecosystems are made up of both the living and the non-living components that are in a continuous state of interaction. The living components such as plants, animals, and microorganisms are referred to as biotic factors. The energy required by living organisms for their survival, growth, and reproduction is derived from their physical environment and other organisms in the lower hierarchy of the food chain. The non-living components that are referred to as biotic include the physical and chemical factors such as water, air, nutrients, and solar energy that influence living organisms. The major types of ecosystems are the terrestrial and aquatic ecosystems (Dash, 2011, p. 145). A terrestrial ecosystem is that located above sea level and is not heavily saturated with water, while an aquatic ecosystem is located in water bodies. Several sub-ecosystems are found under each of the two types of ecosystems.
The terrestrial ecosystems are broadly categorized into forest, desert, mountain, and grassland ecosystems. The forest ecosystem is dominated by trees and plant undergrowths, together with animals and microorganisms. The density of living organisms in a forest ecosystem is high since it is a favorable environment for a diversity of organisms. The forest ecosystems vary across the world due to the different climatic conditions that different areas experience. We therefore have tropical, temperate, and taiga forest ecosystems that vary with increase in latitude respectively. The desert ecosystems have lower density of living organisms due to the inadequate moisture and extreme temperatures during the day and night. The conditions of desert ecosystems vary with altitude and latitude.
The mountain ecosystem is characterized by scattered and diverse range of habitats that support a large number of flora and fauna. The species of plants and animals vary with the altitude of a mountain since higher altitudes have harsh environmental conditions hence requiring highly adaptive species of plants and animals. Grassland ecosystems are present in both tropical and temperate lands, but have slight variation. This ecosystem is mainly comprised of grasses with scattered trees and shrubs, and a variety of animals and other microorganisms. The tropical grassland is referred to as savanna, while the temperate grassland is referred to as prairies. The savanna is seasonally dry with few individual trees and shrubs, while the prairies lack shrubs and trees.
The aquatic ecosystem is comprised of the marine and freshwater sub ecosystems. The amount of salts dissolved in water is the main criteria used in determining the nature of an aquatic ecosystem. The marine ecosystems contain high levels of salts content, while freshwater ecosystems have low levels of dissolved salts. The marine ecosystems are the biggest ecosystems since they cover approximately 71 percent of the earth’s surface, and contain about 97 percent of the planet’s water. Pelagic marine ecosystem is that made up by organisms that are not attached to the bottom of the water bodies. The benthic marine ecosystem is made up of organisms that live on the ocean bottom, but are not necessarily attached to the bottom of these water bodies. The estuary ecosystem is comprised of shallow and partially enclosed areas where fresh water enters the oceans. Their saltiness varies with changes in tides and flow of water from the rivers. This ecosystem is highly productive due to the large amounts of nutrients introduced into them from the rivers and the penetration of light into its shallow basins.
The three types of freshwater ecosystems include lentic, lotic, and wetland ecosystems. The lentic freshwater ecosystem is that having slow moving or static water such as lakes and ponds, while the lotic freshwater ecosystem has fast moving water often found in rivers and streams. Wetlands are low-lying areas that are flooded permanently or intermittently by water, and are usually highly productive with greater organisms diversity.
Characteristics of Living Things
In ecological studies, the term population refers to a group of living organisms of one species that occupies a particular habitat. When the populations of various species existing in a particular habitat are combined, they will form a community of organisms. The organisms in an ecosystem are classified as either producers (autotrophs) or consumers (heterotrophs). The producers have the capability of making their own food from compounds obtained from their environment, while consumers get their energy and nutrients by feeding on other organisms and their remains. The living organisms are different from the non-living organisms in different ways. The first difference is that living things are able to grow in size, reproduce and repair their worn out or injured parts.
Reproduction ensures the continuity of the living organism’s species. Living things require energy for survival, growth and reproduction. Living things are able to respond to changes in their environment mostly for survival purposes. All living things have a lifespan, whereby they grow old and eventually die. Livings also produce waste that they release to the external environment.
Dash, M. C. (2001). Fundamentals of ecology. New Delhi: Tata McGraW-Hill.
Running head: ECOSYSTEMS 1
Isacat, Ben. How to Do Animal Rights. Oxford: Roger Panaman, 2008. Accessed on October/11th/2013 from http://www.animalethics.org.uk/animal-rights.html
Isacalet Ben is a renowned conservationist, biologist and an animal rights activist. He holds a bachelors’ degree in psychology and biology. Further, he possesses a doctorate in animal behavioral ecology. The author of this book currently lives in Oxford Britain.
The text is considered as one of the persuasive and informative text of ages on the treatment of animals in relation to human dignity. The main ideas of the book are radical and compelling to include every audience in the discussion. The author provides reasonable arguments and discussions that include both the vivisectionists and ranchers in his main agenda. Through his logically arranged ideas, the book is considered one of the best in human relation to animals.
The work in this book clearly illustrates the concept of human/animal rights as Lord provided them. It depicts the original vision and will of God on how the state of natural habitat was meant to be attended by man. He justifies the equal rights of animals to humans. The book illustrates the several injustices that animals are subjected to by human without considering that they also experience pain, emotions, and pleasure. Through its constant advocacy for the relevant rights that are appropriate to the animals, such as right to reproduce, live free, and express normal behavior this paper is developed.
Wendy Atkins-Sayre. Articulating Identity: People for the Ethical Treatment of Animals and the Animal-Human divide. Ebscohost.com. 14 11 2013 https://web.ebscohost.com/ehost/detail?vid=4&sid=fbfc139a-572a-4772-a856b56a079f796d%40sessionmgr114&hid=128&bdata=JnNpdGU9ZWhvc3QtbGl2ZQ%3d%3d#db=asu&AN=505377494
Wendy Atkins holds a PhD in communication from the University of Georgia. Currently, she is an assistant professor of communication from the University of Mississippi.
Her article The People for the Ethical Treatment of Animals (PETA) clearly provides a daunting argument on the shared identity and rights of animals/humans. It challenges Humane/animal divide on their shared appeals. The PETA author provides specific rhetorical campaigns of articulation and identity of the nature.
The article develops a reasonable approach to the rhetoric of the social view on human/ animal relation. The writer criticizes some of the images painted by animal rights activists on fur-farms She notes that the work of these organizations is just unfair and advocates for minimal use of animals in fashion. The Organization of PETA has portrayed the cruelity of the fashion industry on animals.
Laemel Briana N Friend, Foe, or Frock: Animal Rights in Fashion. www.fashionwithaheart.wordpress.com. May 2012. Word-press. Date accessed October/9th/2013 from http://fashionwithaheart.wordpress.com/2012/05/06/friend-foe-or-frock-animal-rights-in-fashion/
Laemel N. Brian is a renowned biologist and animal activist for several years. He is a member of the PETA community and considered as one of the best scholars on human/animal related issues.
The article Friend, Foe, or Frock: Animal Rights in Fashion illustrate the prevalent cases that cause cruelty and faux fabrics between animals and humans. It therefore advocates for ethical fashions that are sustainable and renewable. The article urges human to carry out responsible corporate social responsibility standards for animals too.
On this paper, the article has promptly helped in developing the logical views on ethical matters relating to the human / animal relationship. Through the article, it is ultimately clear that immeasurable suffering have been inflicted on animals by human in search of fashion, an issue that is fully condemned.
Social Construction and Human Ecology Theory
Various factors affect families in fostering and maintaining sustainable healthy growth and development procedures for their children. Several authors have emphasized on intra-familial parent-child interactive procedures. This article will focus on the external factors also referred to as extra-familial conditions influencing child growth and family cohesion. Environmental settings both internal and external often impact and influence family structures as well as child growth and development in different and diverse capacities. The intra-familial procedures tend to be influenced by external environments. The external environmental structures include mesosytem models, exosytem models, and chronosystem models (Bronfenbrenner, 1986, p. 723).
Mesosystem models define a family set up as the core area where human growth and development is witnessed for both children and adults. However, various operations and functions in diverse family settings are not independent of the other. For example, the influence a child receives at home may not affect their school performance. Therefore, Mesosytem models characterize analytic models influencing growth and development procedures across principal settings.
Exosystem models apply the findings retrieved from investigations conducted on the psychological growth and development. Children can be affected and influenced by happenings within the surroundings they spend most of their growth and development time in. They can also be influenced when they spend time in areas where their parent’s spend their time like their workstations. This is despite the limited visits they pay to these areas. The majority of children also have limited access to their parent’s friends. However, this does not inhibit their parents’ friends from influencing them directly or/and indirectly (Bronfenbrenner, 1986, p. 723).
These settings form an external environmental platform influencing child growth and development procedures. Therefore, it is crucial to conduct research and investigations on the various influences attributed to these environmental settings to human ecology and social constructs. Conversely, chronosystem is a term applied in defining a designated research model. The model is used in examining influencing factors on overtime development stages among people based on the present environmental settings found within their residential areas. Passing time relations are synonymous across chronological ages utilized in researching psychological changes among people as they mature. My family experience has been influenced positively to a rate of 78% in approximate terms (Bronfenbrenner, 1986, p. 724).
Social construction refers to independent contingent aspects influencing social values and principles. People growing up in different countries are influenced by different social aspects that can be religious or cultural. This is because different societies have different and diverse values, wants, needs, interests, expectations, principles, and desires. For example, India is a cultural country where citizens survive in extreme poverty. However, due to their beliefs and society expectations, a family with a girl child neither perceives that child as a blessing nor a person who can deliver the family from poverty. This explains why Santosh’ father, Gopal, shed tears when she was born as he expected his first born to be a son (WideAngle, 2005, 1.13 min).
She explained how it was difficult growing up in a family setting where her father paid more attention to her two brothers than her. Her father enrolled her to a public school where the school fees paid was lower compared to the amount paid for her brothers who were enrolled in a private school. Therefore, the social construction in India as her father explained does not value a girl child as highly and equally as a boy child. Her father preferred her gaining education to the tenth grade and getting married rather than acquiring higher education to gain skills and expertise, a fact her mother had no control over (WideAngle, 2005, 1.36min).
These assertions are supported by the human ecology theory. The theory’s principles are based on interactive factors in an environment influencing an ecosystem, such as a family. A family behaves according to the societal opinions, cultural expectations, and religious beliefs, to live harmoniously with the neighbors. The theory asserts that in order to integrate with other people and cooperate based on the demands and commands of the ecosystem, an individual ought to hold their own interdependent resources, demands, values and principles.
However, they should be balanced with those of an ecosystem in order to maintain individual freedom and autonomy in a larger ecosystem. Jefferson on the other hand lives in Rio de Janeiro in Brazil. Unlike Santosh, Jefferson is influenced by sociopolitical and economic systems, peers, and urban dwellings mainly education. Therefore, they both have similar mesosystem models (Bronfenbrenner, 1986, p. 724).
This is because education improved Santosh’s life as her parents, especially her father are proud of her after she decided to further her education and acquired a job, thus providing for the family (WideAngle, 2005, 1.00 min). Although Jefferson may not be providing for the family, education improved and enhanced his domestic life at home. Bronfebrenner’s (1986) research findings define communication opportunities and decision making abilities as initiatives in attaining an independent life. Therefore, they should influence socioeconomic race and status positively, such as eliminating poverty, reducing predictors of mental illnesses, delinquent behaviors among children, and consequently promoting family stability. Social construct is the concept I have referred as having the greatest impact on my family to a rate of 86% in approximate terms as well.
Santosh and Jefferson provided perfect examples on how various factors influencing child growth and development affect families in different capacities. Jefferson from an urban environmental set up grew up with a parent afraid he would be influenced to undertake unethical behaviors. Santosh on the other hand grew up in a social context where she was not expected to mature into an independent woman unless she got married. However, due to education and support from the family and a cooperating society, they both gained education transforming to be important people respected within their community. Thus, they shunned religious and cultural beliefs influencing their growth and development. There are different and diverse external environments that tend to influence families in similar ways but in diverse human ecological capacities.
WideAngle. (2005). New Confidence: Women Wanting to Work, Review of the film 1-800 India, Retrieved on 13th September 2013 from: http://www.thirteen.org/edonline/wideangle/videobank/800india_confidence.html
WideAngle. (2005). The Value of a Girl: Women Wanting to Work, Review of the film 1-800 India, Retrieved on 13th September 2013 from: http://www.thirteen.org/edonline/wideangle/videobank/800india_girl.html
Bronfenbrenner, U. (1986). Ecology of the family as a context for human development: Research perspectives. Developmental Psychology, 22(3): 723-742.
Running head: ECOLOGY 1
Fresh Water Resources
Peak renewable water defines systems within which flow constraints inhibit availability of water over a certain period of time. Peak non-renewable water is applicable in ground water systems where the rate at which products are developed exceeds the natural water recharge, and the rate at which water is pumped or contaminated leads to initial increase in output, but a subsequent decline in water supply. Peak ecological water is the peak point beyond which the impact of exploitation and pollution may exceed the positive impact attributed by human acts in relation to water use (Gleick 11155).
Peak water is similar to peak oil because they both define the process of availability and decline of important resources that are crucial in the process of production. The analogy is important as it can help in analyzing various constraints that inhibit water availability, hence, proper water management to ensure sustainability (11156).
Although US GDP and US water withdrawals have been in lock step for almost 70 years, they diverged in the 1970s because of rapid change of national economy, increased efficiency in water use, increased constraints that inhibit accessibility to new water sources as well as the introduction of Clean Water Act (11157).
Hard path defines the construction of water facilities that mainly include dams, pipes and centralized water plants. Soft path defines water projects that often complement the hard path projects, and they are often decentralized and managed at community level. Hard path has attributed to negative environmental impacts in that it has led to displacement of people from flooded villages, inadequate flow of water into the rivers and depletion of important nutrients.
The most serious water problem that has not yet been addressed is the consistent inability to meet the primary human need for water. This leads to spread of water related diseases as well as deaths resulting from the inability to meet this crucial basic need (1525).
Although forecasts indicated that water withdrawals might rapidly increase in the near future, a significant stabilization has been realized with the recognition of severe social as well as environmental costs attributed by the construction of dams.
Considering soft path solutions is cost effective since this approach relies on carefully planned management structures that are well integrated with decentralized facilities. This approach reduces cost by concentrating on increasing overall output of water use rather than creating new water sources (1526).
Gleick, Peter H., & Palaniappan, Meena. Peak Water Limits to Freshwater Withdrawal and Use. PNAS 107.25 (2010): 11155-11162.
ADAPTIVE MANAGEMENT THEORY
Adaptive management is one of the most recent theories that have emerged that explains the uncertainties in the ecosystem. The theory provides methods that are used to predict what the ecosystem will look like in future following the many dangers that it faces while at the same time looks into the measures to be taken to protect it.
The adaptive management theory works by enhancing learning about the environmental factors through field experiments. A decision is then reached based on the results obtained. Before the adaptive management, the traditional methods were used to address environmental issues. These methods failed due to lack of a clear basis (Gardener, 2013). The adaptive management plan emerged after failure of the traditional approach. There are two approaches used in the adaptive management, the active, and the inactive management approach. Active management is a more scientific approach. It emphasizes learning of the environment through experimentation and the results obtained are useful in analysis. On the other hand, passive management monitors the environment and then uses the result obtained.
There are several challenges to the environmental adaptive management. First is the lack of a consistent definition. For instance, the United States forest service in its 2008 rule defines adaptive management as a system of management practices based on clearly identified outcomes and monitoring to determine if management actions are meeting desired outcomes, and, if not, to facilitate management changes that will best ensure that outcomes are met or re-evaluated (Gardener, 2013). The department of Interior on the other hand defines adaptive management as being much about predicting new ways, exploring possibilities and learning about impact of management actions. Another similar challenge is lack of an accepted approach. Scientists and agencies take different approaches to the theory that becomes a major setback for them to work together. Another impediment to adaptive management success is the lack of regulatory standards and statutory authorities. Currently, the theory is only a policy and it is not mandated legally, an issue that causes a problem in its implementation. Another major problem is that stakeholders are not usually involved in the adaptive management process.
Gardener, (2013) discusses the case of Ninth Circuit court of Appeal as an example that illustrates the challenges that agencies go through in implementing adaptive management. The court rejected a plan to remove the grizzly bears from ESA’s list of threatened species. However, scientific study has shown that the bear was affected by climate change.
Lastly, the main shortcoming in adaptive management is the lack of funding. This renders the plan implementation process complex. However, the issue of Genetically Modified Organisms, GMO has been a controversial debate with some wondering where they get their funding amidst growing concern over the effect of biotechnology on the environment.
The statutory authority should be enacted to advice the agencies and courts when to apply adaptive management. Other than statutory authorities, regulatory standards should also be defined to assist in the same. Secondly, stakeholders should be involved early enough in designing, implementation, and reviewing the plans of the implementations. The issue of inadequate funding can be solved when the state allocates funds to the relevant agencies to allow for proper planning.
The environmental adaptive management plan is only possible if the drawbacks to implementations are eliminated and proper action is taken. Such actions include enacting statutory authority and involving stakeholders early enough. The state should also allocate adequate fund to plan implementation. For instance, the Fish Wildlife and Plant, (FWP) strategy that is underway to enhance development of adequate management in the US should be supported through funding.
Gardner, E. (2013). Adaptive Management in face of Climate Change and Endangered Species
Protection. Ecology Law Quarterly, 40(2), 229-270.
ADAPTIVE MANAGEMENT THEORY 2
Running Head: ADAPTIVE MANAGEMENT THEORY 1
The evolutionary origins of beneficial alleles in garter snakes to tetrotoxin
Phylogenetic study reveals that different organisms are related by one common ancestry. However, different organisms have different adaptations to different ecological challenges. Some organisms belonging to the same taxa but residing in different geographical regions with different ecological challenges are found to have different adaptive variants suited to that local environment. The question among evolutionists is where do these genetic variants behind adaptive change come from? There is a loss as to whether these changes are brought about by adaptive alleles recruited through natural selection from standing variations within a population or are moved through introgression from one population to another, or are brought about by novel mutations (Feldman, Brodie & Pfrender 2009).
These uncertainties formed the hypothetical body of inquiry by Feldmana R Chris, Brodie D Edmund, and Pfrender E Michael in their work titled The evolutionary origins of beneficial alleles during the repeated adaptation of garter snakes to deadly prey. It is observed that there is a co-evolutionary arms race between garter snakes, Thamnophis and the newts. The former have developed a growing resistance to TTX poison which is used by the later as a defense mechanism against its predators.
What is striking in their research is how deductive Phylogenetic analyses are employed in reaching the final conclusion that the increased resistance against TTX in the three species of garter snake studies; T. sirtalis, T. couchii, and T. sirtalis is as a result of adaptive evolution occurring independently many times in garter snakes, found in west North America, through de novo acquisition of beneficial alleles (Feldman, Brodie & Pfrender 2009). There is a substantive degree of conviction in the use of Bioassay method in Phylogenetic study to establish that elevated TTX resistance in garter snakes is a derived trait and not a product of genetic introgression. However, I hold a divergent view to the singled conclusions that adaptive resistance to TTX toxins in garter snakes has evolved via ne acquisition of beneficial mutations. In my opinion, the adaptive variations are a subject of both pre-existing standing genetic variants and novel mutations which is emergent from the research article.
Reply to classmates’ discussion
I agree with these views to some extent. It is true that the authors of the article acknowledge that the species of garter snakes that reside in an environment where there are newts are more resistant to tetrotoxin (TTX) poison than those far away. Their findings indicate that other species of Thamnophis and natracine species that reside in an environment free of newts had some level of resistance to TTX poison. These findings are partly consistent with molecular evolutionary phylogeny that the resistance owes its origin from horizontal transfer of beneficial alleles from a common ancestral stock.
In my opinion, the researchers merely wished away the other hypothesis on the origin of the adaptive variants responsible for resistance in garter snakes against TTX poison. They were only able to establish the fact that there exists a variation in the level of resistance to tetrotoxin among Thamnophis species. This is because all the species of garter snakes and natracine species which were studied had varying degree of resistance. The article is complex to comprehend, but the generalized understanding of the research findings is that genetic variants responsible for observed resistance in garter snakes against TTX poison is an integral function of the two hypotheses that were set forth at the onset of the study.
If resistance was observed in all species of snakes, irrespective of their proximity to the newts’ habitats, then it is true that unique resistance alleles are an integral fit of both standing genetic variations within Thamnophis species and mutation which can either be somatic or inherited. One way through which genetic mutation can be transferred from one stock to another is through hybridization which has been wished away in this research. This argument stresses that those resistance alleles that characterizes the resistance observed in garter snakes against TTX poison were present before the split of the lineage by geography.
There are two ways through which garter snakes can have adapted to the novel environments: either through selection on the basis of pre-existing genetic variations or selection on novel mutations. In this case, the novel selective pressure is TTX toxins. The response with which an organism responds to an ecological challenge determines which of the two adaptation ways is suitable. Adaptation from standing genetic variations is always faster than new mutation because beneficial alleles are normally already available and starts at a higher frequency. Another reason is because the beneficial alleles that are present as standing variants are older and may have undergone a prior test by natural selection in a past ecology, another range of species, or another species born through hybridization with the species in question. This theoretical scenario is true of the resistance of garter snakes to newt poison.
Despite my divergent views to the generalized findings, I agree with the singled conclusion that elevated resistance to TTX toxin has evolved independently within different species of garter snakes via convergent changes in Nav1.4.
Feldman,R.C,Brodie, D. E, Pfrender, E.M. (2009). The evolutionary origins of beneficial alleles during the repeated adaptation of garter snakes to deadly prey. pages:1-6.
Evolutionary Origins of Beneficial Alleles in Garter Snakes to Tetrotoxin 1
The planet Earth is the only planet that supports and sustains human life. The human activities carried out on the planet are gradually making the planet unfavorable to live on (Perman 81). Ecology involves the study of relationships between living organisms and their usual natural environment. This paper will define ecological footprint, present a deep understanding of the ecological footprint and show how it applies in measuring the peoples’ effects to the environment. The paper will also explain how the ecological footprint can be used in making choices that go in line with people’s lifestyles.
The principles of ecological footprint date back to literatures related to geography, ecology and economics. However, the idea of the earth’s ecological footprint has been present since early 90’s (Wackernagel 35). William Rees in 1992 produced the first academic publication on ecological footprint. The concept of ecological footprint and calculation criteria was later developed by Mathis Wackernagel as a PhD dissertation under the supervision of Rees at British Columbia University in Vancouver. Originally, the concept was called the appropriated carrying capacity. Rees later came up with the ecological footprint term in order to ensure that the concept is accessible.
The ecological footprint in the planet has transpired as the earth’s vital gauge of the individual’s demand on the environment and the entire nature. It is used in measuring the amount of land and area under water that the human population requires. The ecological footprint can be calculated by taking into consideration the entire biological materials that consumed and the total biological wastes that are produced annually by an individual.
Ecological Footprint measure
Ecological footprint measures human demand of the Earth’s ecology. The ecological footprint is a harmonized measure of natural capital demand against the planet’s ability to regenerate. The footprint represents the total productive earth and the sea area required in supplying the resources that people consume, and to incorporate the related waste. Through ecological footprint assessment, it can be estimated on the earth size required in supporting humanity on the planet. In the year 2007, the earth’s ecological footprint estimate was 1.5 planet Earths. This ecological foot print means that humanity is using the earth’s ecological services at a rate which is 1.5 times than the Earth can replenish them (Perman 66). The methods used in measuring and calculating the ecological footprints vary significantly. However, new standards have been developed in making the results more consistent and comparable.
Ecological footprint seeks to answer a particular research question. What is the amount of the biological land capacity required by a population or human activity? The ecological footprint in answering this question measures the quantity of land that is biologically productive and the total amount of water area a person, country, city, region, or entire humanity population uses in producing resources that it can consume and also absorb carbon dioxide gas emissions emitted with regards to the present technology and other resource management operations. The biologically productive land on the planet include the forests, croplands and the fishing grounds while excluding the glaciers, the open ocean and the deserts.
Ecological footprint uses global hectares as the global average productivity ratio for all the land that is productive and the area under water in a given year. Current studies in compliance to ecological footprints use global hectares as a standard in measurement. This has made the ecological footprint be globally comparable, the same way financial assessments employ one currency.
Calculation of Ecological Footprint
Ecological Footprints is usually calculated for individuals, nation, and other activities (for example manufacturing of a product). The ecological footprint for an individual is usually calculated by taking into account the total biological materials consumed and the total carbon dioxide emitted by the individual throughout the a given year. The materials and wastes are then translated individually into corresponding global hectares. The amount of materials consumed (tonnes per year) by the individual is divided by the specific land or sea area yield (annual tonnes per hectare) after converting to global hectares. The total of global hectares required in supporting the consumption of resource and carbon dioxide emitted for the individual result in n individual’s total ecological footprint.
The ecological footprint comprising of a group of people (a city or nation) is the total of the ecological footprints of all individuals in the nation or region. The ecological footprint for any activity such as the production of goods and services can also be obtained. This is obtained through summing of the total ecological footprints of the materials consumed in a year and the carbon dioxide that is emitted by the activity.
The ecological footprint is used in measuring the extent to which humankind is using natural resources. According to Perman the average world population has an ecological footprint of 2.6 global mean hectares while the biologically productive land and water area per capita is only about 2.05 global hectares (73). This shows that mankind has already exceeded the global biological capacity by 31% he is living unsustainably depleting the natural capital stock. In conclusion, key opportunities are available in reversing the current degradation trends. This will include the creation of resource efficient infrastructure and cities and through campaigning for better practice of the green technology and innovation.
Perman R. Natural Resource and Environmental Economics. Essex: Pearson Education
Wackernagel M. Our Ecological Footprint:Reducing Human Impact on . Philadelphia: New Society Publishers, 1995.
Bollati, V., & Baccarelli, A. (2010). Environmental epigenetic. Heredity, 105(1), 105-112.
Bollati and Baccarelli in their article environmental epigenetic have defined epigenetic as the study of heritable changes in the gene expression that might occur even without the involvement of the DNA sequence from the article, the genomic factors under the influence of exogenous provides a mechanisms for stable propagation of gene activity. There are two epigenetic that can be inherited with chromosomes and these include the DNA methylation and histone modification.
Environmental factors like heavy pollutants like metals, phytoestrogens and poly hydrocarbons among other chemicals may lead to epigenetic factors that are heritable. The epigenetic disease occurs as a result of the interaction between individual genetic makeup and the environmental factors. In the gene-environment interaction, the traits that determine the effect of modification follow the model of dominant, codominant and recessive. In mammals, DNA methylation is vital for embryogenesis when methylation patterns changes to adapt embryos to be fit for further differentiation. The reprogramming sally takes place in the zygote and primordial germ cell formation stages. Experiments done indicate that epigenetic marks can be passed from one generation to another.
Smith, G., & Ritchie, M. G. (2013). How might epigenetic contribute to ecological speciation? Current Zoology, 59(5).
According to these writers, speciation occurs as a result of adaptation of the population to different environments and the concurrent evolution of the reproductive isolation that leads to increased compatibility. The ecological speciation requires diverse selection from the biotic and abiotic environments. Some processes involved in the speciation process include the phenotypic plasticity, which is defined as the change in an organism trait as a result of response to an environmental sign.
This may entail the hierarchical levels of response as well as the phenotypic categories that include life history, morphological, behavioral and learning. The phenotypic plasticity facilitates speciation. Another characteristic is the epigenetic mechanism and evolution, which explains the capability of a stable heritable phenotype that arises from the changes in the chromosomes alteration in the DNA sequence. Despite this fact, it should be known that the epigenetic marks are not necessarily heritable but can be a result of environmental induction. The epigenetic marks are responsible for normal development but the environment can modify them through phenotypic plasticity. These epigenetic marks play vital roles in adaptive evolution.
Baranowski, E., Ruiz-Jarabo, C. M., & Domingo, E. (2001). Evolution of cell recognition by viruses. Science, 292(5519), 1102-1105.
The authors of the article, the evolution of cell recognition by viruses indicates that animal and bacteria viruses enter the cell through some specific receptors. The receptors used by the viruses belong to various protein, carbohydrates, or liquid families and some of these families are used in the immune modulation or in the signaling pathways and cell cohesion. Some of these families do not have any function. It is not possible to determine or anticipate the use of any one receptor molecule, but at least two receptors are responsible for mediating into the cells.
The structures responsible for immune responses are not obvious but are subsets of other types of molecules found on the cell surface and trigger the uptake of the virus molecules. For the virus to enter there must be an uncoating and genome replication. It is believed that amino acid replacements in surface protein or in the capsid affect the recognition of receptors, pathogenesis and the cell tropism. Complete cellular and viral genome indicates that viruses evolved in the cellular world. Minimal changes in the cell genome may lead to the shifting of the receptor sage for virus entry
Baranowski, E., Ruiz-Jarabo, C. M., & Domingo, E. (2001). Evolution of cell recognition by viruses. Science, 292(5519), 1102-1105.
Bollati, V., & Baccarelli, A. (2010). Environmental epigenetic. Heredity, 105(1), 105-112.
Smith, G., & Ritchie, M. G. (2013). How might epigenetic contribute to ecological speciation? Current Zoology, 59(5).
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