THE SCIENCE OF LIFE

    Evolution is the driving force in biology. We are the result of billions of years of evolution , and not only we, but all of life around us, are constantly evolving. It is important that we understand evolution, how it affects our lives and find ways to modify the stream of biological process to enhance our future.

What Is Evolution?
     Biological evolution refers to the increasing changes that occur in a population over time. These change are produced at the genetic level as organisms genes combine in different ways during reproduction and are passed on to future generation.

Why Does It Occur?
      Evolution in organisms occurs through changes in heritable traits i.e. particular characteristics of an organism. In humans, for example, eye colour is an inherited characteristic, which individuals can inherit from one of their parents. Inherited traits are controlled by genes  and the complete set of genes within an organism's genome is called its genotype. The complete set of observable traits that make up the structure and behavior of an organism is called its phenotype. These traits come from the interaction of its genotype with the environment. As a result, not every aspect of an organism's phenotype is inherited. Suntanned skin results from the interaction between a person's genotype and sunlight, thus, suntans are not passed on to people's children.

How Are Traits Passed On?
        Sometimes, individuals inherit new characteristics that give them a survival and reproductive advantage in their local environments. These characteristics tend to increase in frequency, while those that are disadvantageous decrease in frequency.This process of different survival and reproduction is known as natural section. Non-genetic changes that occur during an organism's life span, such as increase in muscle mass due to diet and exercise, cannot be passed on to the next generation and are not examples of evolution. The survival of reproductive success of an individual is directly related to the ways its inherited traits function in the context of its local environment.

What  Do Genes Have To Do With Evolution?
           Genes are the portions of an organism's DNA that carry the code responsible for building that organism in a very specific way. Genes, thus, the traits they code for are passed from parent to offspring. From generation to generation, well-understood molecular organisms reshuffle, duplicate, and alter genes in a way that produces genetic variation. This variation is the raw material for evolution. Heritable traits are propagated between generations via DNA, a molecule which is capable of encoding genetic information.

Evolution In Your World:-
            Evolution is a topic that touches your life every day . The cereal you eat for breakfast comes from a grain that has evolved to its current state after generations of artificial selection by humans. If you get a flu shot, the reason you have to get one every year is that viruses constantly evolve , and a vaccine that works this year may not work next year. If you wash your hands with antibacterial soap, you kill some bacteria, but other bacteria have mutations that make them resistant to the agent used in the soap. Evolution is going on all around you all the time, and if you want to help make decisions to protect the environment and ensure a healthy future and a plentiful food supply, you need to understand how it works.

      Humans did not evolve from monkeys. Humans are more closely related to modern apes than to monkeys, but we didn't we didn't evolve from apes either. Humans share a common ancestor with modern African apes, like gorillas and chimpanzees. Scientists believe this common ancestor existed 5 to 8 million years ago. Shortly thereafter, the species diverged into two separate lineages. One of these lineages ultimately  evolved into gorilla and chimps, and the other evolved into early human ancestors called hominids. Homo sapiens, the species to which we belong, has existed for about 100,000 years.

       Evolution is always happening though often at rates far too slow to be observed in a matter of days, weeks or even years. The effects of evolution can be felt in almost every aspect of our daily lives, though from medical and agricultural dilemmas to our children. In agriculture, the need to protect crops makes us evolve pesticide resistance. For all of us, there is the issue of decreasing biodiversity, as most scientists believe that life on earth is currently undergoing a mass extinction in which 50 per cent or more of species will die out. These are just a few examples of ways in which evolutionary processes affect our daily lives.. 

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