EvoluTIOn theory!
_MaD_MaDDy_ 2011/04/13 06:32
_MaD_MaDDy_ 2011/04/13 06:32
Evolution theory explains how organisms have changed over time.
The fossil fish Priscacara liops found in sediments dating from the Eocene epoch (55.8 0.2 to 33.9 0.1 mya) in present day Green River, a tributary of the Colorado, USA.
Scientific understanding requiresboth facts and theories that can explain those facts in a coherent manner. Evolution, in this context,is both a fact and a theory. It is an incontrovertible fact that organisms have changed, or evolved, during the history of life on Earth. And biologists have identified and investigated mechanisms that can explain the major patterns of changeThere are four major patterns of change.
Patterns in Nature
The field of evolutionary biology seeks to provide explanations forfour conspicuous patterns that are manifest in nature. The first three concern living species, whereas the fourth relates to fossils. Genes are linked to how organisms look and behave.
*.Genetic variation. There is tremendous genetic diversity within almost all species, including humans. No two individuals have the same DNA sequence, with the exception of identical twins or clones. This genetic variation contributes to phenotypic variation that is, diversity in the outward appearance and behavior of individuals of the same species. Organisms must adapt to their environment to survive.
*.Adaptation. Living organisms have morphological, biochemical, and behavioral features that make them well adapted for life in the environments in which they are usually found.Fossils provide evidence of evolutionary changes.
*.Fossil species . Fossils are the mineralized remnants or impressions of once-living organisms. Many fossils, such as trilobites and dinosaurs, belong to groups that no longer exist onthe face of the Earth. Conversely, many modern species appear similar to other fossils, yet fossils of the modern species are absentfrom rocks of corresponding ages. The age of the Earth is estimated to be about 4.5 billion years, with the earliest bacterial fossils about 3.5 billion years old. Fossils from around 550 million years ago (the Cambrian period) show a diverse assemblage of multicellular animals. The origin of life remains an unsolved mystery.
Evolutionary biology provides a scientific framework for understanding the changes that have occurred since the first life forms arose on Earth several billion years ago. Biochemists, geologists, and physicists seek natural explanations for the origin of life on Earth.. While progress has been made in this area, the origin of life remains aninteresting, but unanswered, question. When species evolve, their genetic makeup changes. Offspring with genetic mutations are different from their parents. Genes can be shuffled between organisms. Not all mutations become fixed in a population. Natural selection guarantees that the fittest are most likely to pass on their genes.
Mechanisms of Evolution
Biological evolution results from changes over time in the genetic constitution of species. Genetic changes often, but not always, produce noticeable changes in the appearance or behavior of organisms. Evolution requires both the production of variation and the spread of some variants that replace others.
*.Genetic variation arises through two processes, mutationand recombination. Mutation occurs when DNA is imperfectly copied during replication, leadingto a difference between a parents gene and that of its offspringSome mutations affect only one bit in the DNA; others produce rearrangements of largeblocks of DNA.
*.Recombination occurs when genes from two parents are shuffled to produce an offspring, as happens regularly in sexual reproduction. Usually the two parents belong to the same species, but sometimes (especially in bacteria) genes move between more distantly related organisms.
*.The fate of any particular genetic variant depends on two processes, drift and selection. Drift refers to random fluctuations in gene frequency, and its effects are usually seen at the level of DNA. Ten flips of a coin do not always produce exactly five heads and five tails; drift refers to the same statistical issue applied to the transmission of genetic variants across generations.*.The principle of natural selection was discovered by Charles Darwin (1809-1882), and it is the process by which organisms become adapted to their environments. Selection occurs when some individual organisms have genes that encode physical or behavioral features that allow them to betterharvest resources, avoid predators, and such relative to other individuals that do not carry the same genes. The individuals that have these usefulfeatures will tend to leave more offspring than other individuals, so the responsible genes will become more common over time,leading the population as a whole to become better adapted.
The fossil fish Priscacara liops found in sediments dating from the Eocene epoch (55.8 0.2 to 33.9 0.1 mya) in present day Green River, a tributary of the Colorado, USA.
Scientific understanding requiresboth facts and theories that can explain those facts in a coherent manner. Evolution, in this context,is both a fact and a theory. It is an incontrovertible fact that organisms have changed, or evolved, during the history of life on Earth. And biologists have identified and investigated mechanisms that can explain the major patterns of changeThere are four major patterns of change.
Patterns in Nature
The field of evolutionary biology seeks to provide explanations forfour conspicuous patterns that are manifest in nature. The first three concern living species, whereas the fourth relates to fossils. Genes are linked to how organisms look and behave.
*.Genetic variation. There is tremendous genetic diversity within almost all species, including humans. No two individuals have the same DNA sequence, with the exception of identical twins or clones. This genetic variation contributes to phenotypic variation that is, diversity in the outward appearance and behavior of individuals of the same species. Organisms must adapt to their environment to survive.
*.Adaptation. Living organisms have morphological, biochemical, and behavioral features that make them well adapted for life in the environments in which they are usually found.Fossils provide evidence of evolutionary changes.
*.Fossil species . Fossils are the mineralized remnants or impressions of once-living organisms. Many fossils, such as trilobites and dinosaurs, belong to groups that no longer exist onthe face of the Earth. Conversely, many modern species appear similar to other fossils, yet fossils of the modern species are absentfrom rocks of corresponding ages. The age of the Earth is estimated to be about 4.5 billion years, with the earliest bacterial fossils about 3.5 billion years old. Fossils from around 550 million years ago (the Cambrian period) show a diverse assemblage of multicellular animals. The origin of life remains an unsolved mystery.
Evolutionary biology provides a scientific framework for understanding the changes that have occurred since the first life forms arose on Earth several billion years ago. Biochemists, geologists, and physicists seek natural explanations for the origin of life on Earth.. While progress has been made in this area, the origin of life remains aninteresting, but unanswered, question. When species evolve, their genetic makeup changes. Offspring with genetic mutations are different from their parents. Genes can be shuffled between organisms. Not all mutations become fixed in a population. Natural selection guarantees that the fittest are most likely to pass on their genes.
Mechanisms of Evolution
Biological evolution results from changes over time in the genetic constitution of species. Genetic changes often, but not always, produce noticeable changes in the appearance or behavior of organisms. Evolution requires both the production of variation and the spread of some variants that replace others.
*.Genetic variation arises through two processes, mutationand recombination. Mutation occurs when DNA is imperfectly copied during replication, leadingto a difference between a parents gene and that of its offspringSome mutations affect only one bit in the DNA; others produce rearrangements of largeblocks of DNA.
*.Recombination occurs when genes from two parents are shuffled to produce an offspring, as happens regularly in sexual reproduction. Usually the two parents belong to the same species, but sometimes (especially in bacteria) genes move between more distantly related organisms.
*.The fate of any particular genetic variant depends on two processes, drift and selection. Drift refers to random fluctuations in gene frequency, and its effects are usually seen at the level of DNA. Ten flips of a coin do not always produce exactly five heads and five tails; drift refers to the same statistical issue applied to the transmission of genetic variants across generations.*.The principle of natural selection was discovered by Charles Darwin (1809-1882), and it is the process by which organisms become adapted to their environments. Selection occurs when some individual organisms have genes that encode physical or behavioral features that allow them to betterharvest resources, avoid predators, and such relative to other individuals that do not carry the same genes. The individuals that have these usefulfeatures will tend to leave more offspring than other individuals, so the responsible genes will become more common over time,leading the population as a whole to become better adapted.
Lelsi 2011/04/13 10:02
Theory of evolution doesn't have a single proof.
Take for example the theory of evolution of rudimentary organs, which states two arguments:
1.dysfunction: an organ that doesn't work was forced earlier to be able to function. This function is equated with stunted growth.
2. homology comparison of species with and without some kind of rudiment. eg. whale has bones that correspond to the hindlimb bones of land mammals, the theory of evolution implies, in accordance with a belief in common origin, that there has been a stunted growth hindlimb of ancestors of whales .
This is factually incorrect. As first there are no dysfunctional organs.
The already mentioned rudimentary pelvic and femoral bones of whales serve as binding places for the muscles of the genitals and anus muscle.
It is obvious proof that this organ isn't rudimentary, for without these bones, whales wouldn't be able to dive well and they wouldn't be unable to reproduce.
As second homology has nothing to do with evolution.
As a third many of the greatest scientists believed that GOD created all life and earth and the universe, and among them are the Pasteur, Mendel, Morse, Newton, Fleming, Kepler, Pascal..
Theory of evolution doesn't have a single proof.
Take for example the theory of evolution of rudimentary organs, which states two arguments:
1.dysfunction: an organ that doesn't work was forced earlier to be able to function. This function is equated with stunted growth.
2. homology comparison of species with and without some kind of rudiment. eg. whale has bones that correspond to the hindlimb bones of land mammals, the theory of evolution implies, in accordance with a belief in common origin, that there has been a stunted growth hindlimb of ancestors of whales .
This is factually incorrect. As first there are no dysfunctional organs.
The already mentioned rudimentary pelvic and femoral bones of whales serve as binding places for the muscles of the genitals and anus muscle.
It is obvious proof that this organ isn't rudimentary, for without these bones, whales wouldn't be able to dive well and they wouldn't be unable to reproduce.
As second homology has nothing to do with evolution.
As a third many of the greatest scientists believed that GOD created all life and earth and the universe, and among them are the Pasteur, Mendel, Morse, Newton, Fleming, Kepler, Pascal..
LoneLy_heArt 2011/04/13 10:19
In the beginning God created heaven, and the earth upon which thou standest. The earth was without form . and void, then light appeared. God made a firmament and two waters, the greater of which was beneath the firmament, the lesser above.
The waters were gathered together; dry land appeared. Plants came forth upon the dry land. Sun, moon, and stars appeared. Sea life, winged creatures, and then the land animals. And lastly God created mankind.
In the beginning God created heaven, and the earth upon which thou standest. The earth was without form . and void, then light appeared. God made a firmament and two waters, the greater of which was beneath the firmament, the lesser above.
The waters were gathered together; dry land appeared. Plants came forth upon the dry land. Sun, moon, and stars appeared. Sea life, winged creatures, and then the land animals. And lastly God created mankind.
Mahesh 2011/04/13 11:22
Every fossil is a transitional fossil. If you want living proof that Darwin's theory of natural selection is true look at yourdog and compare it to yourself. Both you and the dog have hair. Feel the bones in your dog's arm. Youhave the exact same bones in your arm. Both you and the dog have nipples. Under the skin, both you and your dog have a four chambered heart, your both endothermic(warm blooded), etc. All thosefeatures classify us and the dog as mammals. If we didn't share a common ancestor with the dog, we would have drastically different features,but we don't. Even better lets compare ourselves to the chimpanzee our closest cousin. We both have four fingers with an opposable thumb, same looking ears, nohair on the palms of our hands and feet, we both use tools, we both have a brow ridge (though theirs is more pronounced), we have the same number of teeth, eight incisors, four canines, eight pre-molars, 12 molars etc. etc. etc. We have also found hundreds of fossils of humans that lived way before 6000 years ago. Lucy the Australopithecus, Homo habilis, Homo erectus, Homo heidelbergensis, and Homo sapiens.
There are so many similarities between us and other animals, it would be ignorant to believe we have no relation to them whatsoever. I believe in god too, but I also take an interest in biology, especially evolution.
Every fossil is a transitional fossil. If you want living proof that Darwin's theory of natural selection is true look at yourdog and compare it to yourself. Both you and the dog have hair. Feel the bones in your dog's arm. Youhave the exact same bones in your arm. Both you and the dog have nipples. Under the skin, both you and your dog have a four chambered heart, your both endothermic(warm blooded), etc. All thosefeatures classify us and the dog as mammals. If we didn't share a common ancestor with the dog, we would have drastically different features,but we don't. Even better lets compare ourselves to the chimpanzee our closest cousin. We both have four fingers with an opposable thumb, same looking ears, nohair on the palms of our hands and feet, we both use tools, we both have a brow ridge (though theirs is more pronounced), we have the same number of teeth, eight incisors, four canines, eight pre-molars, 12 molars etc. etc. etc. We have also found hundreds of fossils of humans that lived way before 6000 years ago. Lucy the Australopithecus, Homo habilis, Homo erectus, Homo heidelbergensis, and Homo sapiens.
There are so many similarities between us and other animals, it would be ignorant to believe we have no relation to them whatsoever. I believe in god too, but I also take an interest in biology, especially evolution.
Lelsi 2011/04/13 13:04
The fossil remains have never and nowhere in the world proved "transitional forms" in a gradual evolution of living organisms from primitive to more develpoed types.
Evolutionists are not yet able to explain even the formation of a single protein necessary for life. Calculations of possibilities, physical and chemical formulas have proved the impossibility of accidental genesis of life.
The fossil remains have never and nowhere in the world proved "transitional forms" in a gradual evolution of living organisms from primitive to more develpoed types.
Evolutionists are not yet able to explain even the formation of a single protein necessary for life. Calculations of possibilities, physical and chemical formulas have proved the impossibility of accidental genesis of life.
Undiscover 2011/04/19 19:57
darwins theory is a waste !! a long time ago, his theory was provd wrong !! until now no theory hav prove evolutn !! fossils & homologous organs hav sm wat able 2 prove evolutn !! Nd also...until now no 1 theory is able 2 prove how life came on earth, except dat experiment of synthesis of proteins !!
darwins theory is a waste !! a long time ago, his theory was provd wrong !! until now no theory hav prove evolutn !! fossils & homologous organs hav sm wat able 2 prove evolutn !! Nd also...until now no 1 theory is able 2 prove how life came on earth, except dat experiment of synthesis of proteins !!
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