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από OrderAndChaos » 09 Απρ 2019, 14:06
Λοιπόν, βρήκα στον σκληρό μου μια σειρά απο ξενόγλωσσα κείμενα σχετικά με την εξέλιξη (δεν θυμάμαι απο που τα έχω). Τα παραθέτω εδώ γιατί πιστεύω πως αξίζουν για όποιον θέλει να έχει μια γενική εικόνα για την θεωρία.
Eξέλιξη: Μια επιστημονική θεωρία.
Science is built on facts, much like a house being built of bricks. But a pile of bricks is not a house and a collection of facts is not science. They become science only after being assembled into a coherent explanation of observed phenomena that is a Scientific Theory. Any scientist will tell you that there is no such thing as "only a theory" because A THEORY IN SCIENCE IS THE HIGHEST DEGREE OF CERTAINTY POSSIBLE.
Every determination in science is provisional. In the criminal justice system it is said that everyone is innocent until proven guilty. In the course of a trial, evidence is presented and the jury makes a determination; "guilty" or "not guilty". It is supposed to convey finality. Only it doesn't. We know of far too many cases of wrongful convictions and even executions. That is why, in science NOTHING is ever considered "Proven". Science is a search for truth, and that search never ends.
Science makes determinations based on EVIDENCE and as evidence accumulates in support of an explanation for observed phenomena, the level of certainty increases to the point where the explanation is called a THEORY and regarded as TRUE (but never, ever, 'proven'). It remains TRUE so long as all available evidence is consistent with the theory. Should even one piece of evidence come to light that is NOT consistent with the theory, the theory must be revised or discarded.
The Theory of Evolution is perhaps the most thoroughly tested theory in science, yet if one fossil were to be discovered out of its predicted place in the fossil record, such as a pre-Cambrian fish or a mammal in the Carbonaceous, the theory would be in serious jeopardy.
The facts that build the Theory of Evolution are the vast diversity of life on earth, the hundreds of thousands of transitional fossils, the physiological and genetic similarities, protein redundancy, Endogenous Retroviruses, Pseudo-genes, the unique flora and fauna of isolated islands, and much, much more
Humans are primates The physical similarities between humans and monkeys/apes has been noted since ancient times. We have grasping hands with opposable thumbs, fingernails instead of claws and forward facing eyes, among other common attributes.
One hundred years before Darwin published his "Origin of Species", the Swedish naturalist Carolus Linnaeus (aka Carl von Linne) established a system of classification for living organisms that is still used today. In so doing, he classified humans as Genus Homo and Species sapiens (lower case 's') and placed us in the Order Primates, meaning first order.
Before Darwin arrived at his explanation for the vast diversity of life on this planet, the biblical explanation as commonly accepted without question and Linnaeus ostensibly believed in special creation. However, the resemblance between humans, and chimpanzees was so strong that he initially classified them with us in genus Homo.
Later naturalists refined that classification, placing humans with the other apes in the family Hominidae. With living species today we can use genetics to determine relationships between species, and amazingly Linnaeus was overwhelmingly correct in his assessments.
Our common ancestry with chimps/bonobos is attested to by far more than physical or genetic similarities. Within the genome of any species are not only genes, but pseudo genes; gene that were once active and producing a protein, but no longer due to a disabling mutation. The presence of non functional genes in any species does not fit well with a proposed "intelligent designer".
While there are perhaps an infinite number of mutations that could disable a gene, the fact of two species sharing the same pseudo gene disabled by exactly the same mutation is very strong evidence for common ancestry. One could , supposedly, argue that to be a mere coincidence, but the fact is that in the case of humans and chimps/bonobos there are thousands of such shared pseudo genes, each disabled by the same mutation. Many of those pseudo genes are shared not only with chimps and bonobos, but with other apes as well, again attesting to common ancestry, and still others shared with monkeys and other primates.
One gene, present in most mammals, called GULO enables the synthesis of vitamin C within their body.. That gene is present in the human body, but has been disabled by a mutation. It is a pseudo gene. Humans without fruits and vegetables in their diet get Scurvy, a problem that was most noticeable in the days of sailing ships and long sea voyages. It turns out that that pseudo gene, disabled by the same mutation, is present in the genomes of not just humans and apes, but all primates in the sub order Haplorhini which includes apes (including humans), Old World Monkeys, New World Monkeys and Tarsiers. It is a fully functioning gene in the genomes of the other primate sub order Strepsirrhini (Lemurs and Lorises), indicating that the ancestral disabling mutation took place at the time the two lines diverged, perhaps 55 million years ago.
If the thousands of pseudo genes attesting to common ancestry are not sufficiently convincing, there are also the 16,000 or so viral sequences (Endogenous Retroviruses or ERV's) acquired from ancestral infections that comprise 8% of the human genome as well as those of other vertebrates. When retroviruses infect a cell, they commandeer the replicating machinery of the host cell, inserting a DNA copy of their RNA into the host genome at a random location. When this happens to sperm or egg cells, that viral sequence can be passed to successive generations with the viral sequence trapped at its original location. The same viral sequence (ERV) found at the same location in multiple species is prima facie evidence of common ancestry. Each of these pseudo genes and ERV's originated independently of each other, and each is a separate line of evidence for common ancestry.