I believe that plants evolve, and some other life forms, but when it comes to human beings, that's where it stops. Humans are not the same as animals, because we have what is known as a soul, or spirit. Animals don't. They have pure instinct. We could not have evolved from any animal. Also, look at the sun. It is still there in the sky. That same sun that warmed the faces and lit the days of Adam, Eve and Moses, still burns, is still there and still warms our faces and lights our days. It would be some trick to see science make one of those and suspend it in the sky. I'd also be interested in seeing primordial ooze do this trick as well.
2007-01-03 05:40:25
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answer #1
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answered by classyjazzcreations 5
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If you really want to learn about science, why do you post in the R&S section?
Anyway, here are some hypotheses about abiogenesis. And it's *not* a scientific fact that life can't be created from non life; quite the contrary.
Spontaneous Generation
Classical notions of abiogenesis, now more precisely known as spontaneous generation, held that complex, living organisms are generated by decaying organic substances, e.g. that mice spontaneously appear in stored grain or maggots spontaneously appear in meat.
According to Aristotle it was a readily observable truth that aphids arise from the dew which falls on plants, fleas from putrid matter, mice from dirty hay, and so forth. In the 17th century such assumptions started to be questioned; such as that by Sir Thomas Browne in his Pseudodoxia Epidemica, subtitled Enquiries into Very many Received Tenets, and Commonly Presumed Truths, of 1646, an attack on false beliefs and "vulgar errors." His conclusions were not widely accepted, e.g. his contemporary, Alexander Ross wrote: "To question this (i.e., spontaneous generation) is to question reason, sense and experience. If he doubts of this let him go to Egypt, and there he will find the fields swarming with mice, begot of the mud of Nylus, to the great calamity of the inhabitants."
However, experimental scientists continued to decrease the conditions within which the spontaneous generation of complex organisms could be observed. The first step was taken by the Italian Francesco Redi, who, in 1668, proved that no maggots appeared in meat when flies were prevented from laying eggs. From the seventeenth century onwards it was gradually shown that, at least in the case of all the higher and readily visible organisms, the previous sentiment regarding spontaneous generation was false. The alternative seemed to be omne vivum ex ovo: that every living thing came from a pre-existing living thing.
Then in 1683 Antoni van Leeuwenhoek discovered bacteria, and it was soon found that however carefully organic matter might be protected by screens, or by being placed in stoppered receptacles, putrefaction set in, and was always accompanied by the appearance of myriad bacteria and other low organisms. As knowledge of microscopic forms of life increased, so the apparent realm of abiogenesis increased, and it became tempting to hypothesize that while abiogenesis might not take place for creatures visible to the naked eye, at the microscopic level, living organisms continually arose from inorganic matter.
In 1768 Lazzaro Spallanzani proved that microbes came from the air, and could be killed by boiling. Yet it was not until 1862 that Louis Pasteur performed a series of careful experiments which disproved that organisms such as bacteria and fungi appear in nutrient rich media of their own accord in non-living material and supported cell theory.
Three years earlier, Darwin's On the Origin of Species by Means of Natural Selection (published in 1859), had presented an argument that modern organisms had evolved, over immense periods of time, from simpler ancestral forms, that species changed over time in accordance with cell theory. Darwin himself declined to speculate on some implications of his theory - that at some point there may have existed an ur-organism with no prior ancestor and that such an organism may have come into existence, formed from non-living molecules.
Although Pasteur had demonstrated that modern organisms do not generate spontaneously in nonliving nutrients, science seemed to be moving in opposing directions. However, Pasteur's experiments were limited to a closed limited system for a very brief (geologically) time period of modern scientific experimentation, and not to time scales on millions or billions of years on the open surface of a planet. The ur-organism implication of Darwin's theories would have occurred in the deep geological past, the dawn of time on this planet, 3.87 billion years ago, and it had a billion years from the beginning of the planet to be formed.
Primordial Soup
In 1936 Aleksandr Ivanovich Oparin, in his "The Origin of Life on Earth", demonstrated that organic molecules could be created in an oxygen-less atmosphere, through the action of sunlight. These molecules, he suggested, combine in ever-more complex fashion until they are dissolved into a coacervate droplet. These droplets could then fuse with other droplets and break apart into two replicas of the original. This could be viewed as a primitive form of reproduction and metabolism. Favorable attributes such as increased durability in the structure would survive more often than nonfavorable attributes.
Around the same time J. B. S. Haldane suggested that the earth's pre-biotic oceans - very different from their modern counterparts - would have formed a "hot dilute soup" in which organic compounds, the building blocks of life, could have formed. This idea was called biopoiesis or biopoesis, the process of living matter evolving from self-replicating but nonliving molecules.
In 1953, taking their cue from Oparin and Haldane, the chemists Stanley L. Miller and Harold C. Urey carried out an experiment on the "primeval soup". Within two weeks a racemic mixture of a few amino acids, some of the building blocks of life, had formed from the highly reduced mixture of methane, ammonia, water vapor and hydrogen. While Miller and Urey did not actually create life, they demonstrated that more complex molecules — a few amino-acids — could emerge spontaneously from simpler chemicals. The environment was meant to simulate a primeval earth. It included an external energy source in the form of a spark, representing lightning, and an atmosphere largely devoid of oxygen. There was careful filtering in place to preserve the results from destruction.
Their experiments had different results from Pasteur's because they involved different conditions. Since that time there have been other experiments that continue to look into possible ways for life to have formed from non-living chemicals, e.g. the experiments conducted by Joan Oró in 1961.
2007-01-03 05:31:50
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answer #7
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answered by eldad9 6
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