Variations leads to Evolution

-
Without genetic, variation,  there could be no evolution.  Imagine that all individuals in a special had the exact same set of genes. Their offspring would all be the same, and would all have an equal chance of survival.  It's the variations in genes,  which are expressed as variations in traits that cause some individuals to thrive and others to fall prey to predators and other threats in their environment.  Consider the finch,  the bird that famously caught darwin's attention on his voyage to the Galapagos islands.  Finches have different kinds of beaks,  each one best suited for a particular task. Some beaks are best for cracking hard nuts,  others for reaching into tight spaces,  still others for eating small seeds.
The type of beak that an individual finch has will affect that finch's ability to survive in a given environment . If there is drought that kills the plant that produce small seeds,  the finches with large,  strong beaks that can crack hard nuts will do better than the finches whose beaks were
best suited to eating the now scarce small seeds.

 Natural selection:  acts on observable traits such as the size strength and shape of the finches beaks. An individual's observable traits are called its phenotype,  but it's an individual's DNA , its genotype,  that determines what the phenotype will be.

 
 Evolution of beaks in finches of Galapagos islands
If every individual had the exact same DNA,  the only observable differences among individuals would be those caused by the environment alone. There wouldn't be any variation in inherited traits such as the finches's beak size. If all the finches had the same genes,  they would all have the same type of beak.

 Variation,  competitions,  survival of the fittest leads to Evolution

Comments

Post a Comment

Popular posts from this blog

Components of Ecosystem

-
Image
An ecosystem consist of two major components namely , abiotic components and biotic components. Both these components are equally important for the proper functioning of the ecosystem. a. Abiotic components of Ecosystem The following are the major abiotic components of an ecosystem 1.Light    2. Water   3. Temperature  4. Atmosphere   5. Fire    6. Soil   7. Inorganic material    8. Gravity 1. light Light influences the growth and distribution of living organisms. Plants utilize sunlight during photosynthesis and prepare food. Light intensity, light quality,  light quantity and light duration affect life of animals and plants in one way or the other. For example the plant growing under insufficient light do not develop chlorophyll and they high intensity of light destroys chlorophyll.      Rainforests are home to rich biodiversity present on  2.water  Water is a vital component of life. Water...
Read more

The facts about the creation and the hollowness of the theory of Evolution

-
Image
There is a wide spread unscientific theory in the western world that the organisms of today have evolved from previous ancestors . The theory was proposed by darwin and readily accepted by the west. They theory of evolution states the first unicellular organisms evolved by chance factors.  From unicellular organsms multicellular organsims evolved. And similarly during the course of evolution human beings have evolved from monkey.  And theory in science proposed should be supported by proofs and evidence.  If sufficient evidence based on experiments prove that theory is correct , then it is accepted as a scientific fact.      Western scientists have tried their level best searching and applying all possibilities to make a living cell, but they have failed to do so. With all the sophisticated instruments and modern technology and all possible efforts if the western scientists think tank cannot make a single living cell , then how one can believe that all the...
Read more

Drug Addiction and Associated problems

-
Image
Apart from the nagative physical effects of drug use there are psychological and emotional effects that are equally as devastating. One of the areas that is almost universally damaged is a person's view of oneself,  their self-esteem. Self-esteem virtually never rises when drug use is induced;  it almost always sinks lower and lower. As a person's self-esteem decreases through drug use,  the nagative feeling of worthlessness,  hopelessness , shame and guilt increase.   Drug addicts : a menace for society This is often due to the fact that a person realizes deep down that drug use is a destructive thing to be doing,  yet they do it anyway.  This sets up a contradiction between internal values and actual actions taken. One of the most destructive things that drug use does is it interferes with a person's ability to from caring and honest: relationships. It also tends to destroy relationships that currently exits.  This is essentially due to th...
Read more