Wednesday, 30 July 2014

ENVIRONMENTAL ECOLOGY, BIODIVERSITY AND CLIMATE CHANGE

ENVIRONMENTAL  ECOLOGY, BIODIVERSITY AND CLIMATE CHANGE

BIODIVERSITY:THE BIOLOGICAL PERSPECTIVE

 INTRODUCTION
 The biosphere is a global ecosystem. It includes the entire portion of the earth inhabited by life. In a boarder sense., biospheres are any closed, self- regulating systems. The term “ biosphere” was coined by geologist Eduard Suess in 1875. He defined biosphere as the place on earth’s surface where life dwells.
    The biosphere’s ecological context came from 1920, preceding the 1935 introduction of the term “ecosystems” by sir Arthur Tansley. Valdimir  I. Vernadsky defined ecology as the science of the biosphere. It is an interdisciplinary concept for integrating astronomy, geophysics, meteorology, biogeography, evolution, geology, geochemistry, hydrology and all life and earth sciences . the biosphere is a core concept with biology and ecology. Ecology provides a scientific context for evaluation environmental issues. To address environmental  issues. To address environmental problems, we need to understand the interaction of organisms and their environments. The science of ecology provides that understanding. It is important to communicate the scientific complexity of environmental issues.
Ecology
Ecology is the scientific study of the rich and varied interactions between organisms and their abiotic environment. In ecological studies, the environment encompasses both abiotic (  such as water, mineral nutrients, light , temperature) and biotic factors (living organism). Interactions between organisms and their environment is a two way process in which organisms influence and are influenced by their environment.  There are many reasons to care about ecology. Our lives are enriched by the fascinating interactions between the organisms. Watching a butterfly visiting a flower and bringing about pollination is worth seeing. Beyond simple curiosity, information from ecological sciences is needed to solve many practical problems. An understanding of ecology allows us to grow food, control pests and diseases and deal with natural disasters such as flood, drought and earthquake.
BRANCHES OF ECOLOGY
1. Ecology and Evolution
 Ecology and evolution are considered sister disciplines of the life sciences. Natural selection, life history, development, adaptation, populations and inheritance are examples of concepts that correlate equally into ecological and evolutionary theory.
(a)    Behavioral Ecology   - This is the study of animal behavior in the natural environment, also known as ethology. Behavioral ecology also deals with ecological and evolutionary changes, because of the interactions among the organisms. Adaptation is the central unifying concept in behavioral ecology. The behaviors evolve and become adapted to the ecosystem because they are subject to the forces of natural selection. Consider the edible beetles that direct sprays of poisonous chemicals at their attacker. Predator-prey interactions are an introductory concept in behavioral ecology.

(b)    Social ecology - This is concerned with the relationships between organisms and their environment. Social ecological behaviours are notable in the social insects, slime molds, social spiders and human society. Individuals that belong to a social group have to face competition for food, mates and other limited resources. They face diseases and parasitic many groups. This is known as altruism. (Behavior that harms the individuals who performs it but benefits other individuals.) Through genetic relationship Parenting is also altruism, where the children are benefited. Altruism is extreme among some insect societies, such as honeybee and termite colonies. Groups that are predominantly altruist beat groups that are predominantly selfish.

(c)    Co-evolution -   Populations of the other species are part of my any organism’s environment. The population having prey- predator interactions exert pressure on each other. If prey evolves, the predator counter develops mechanisms to catch the prey. This is the basis of co-evolution in populations. There are many examples where interacting organisms evolve together e.g., lithops (flowering stone) growing in the open are develop stone like pattern and color to hide from herbivores.

(d)   Bio- Geography -This is the comparative study of the geographic distribution of organisms and the corresponding evolution of their traits in space and time. Bio –geographical processes that result in the natural splitting of species explain modern distribution of the earth’s biota (flora and fauna).

2. Molecular Ecology
   Molecular ecology a relatively new field where the important relationship between ecology and genetic inheritance is analyzed using modern techniques of molecular analysis. Molecular ecological research became more feasible with the development of rapid and accessible genetic technologies, such as the polymerase chain reaction (PCR). The DNA of different organisms is compared and their evolutionary relationships are analyzed.
3. Human Ecology
Human ecology is the interdisciplinary investigation into the ecology of our species. It is discipline that inquires into the pattern and process of interaction of humans with their environment. It studies human values, life styles, resource use, waste etc. the human species is not an external disturbance. It is the keystone species within the system.
4. Landscape Ecology
Landscape ecology is a sub discipline of ecology that studies ecological processes that operate over large areas. A landscape ecologist examines the connections among ecosystem found in a particular region.

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