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Journal of Theoretical Biology
Volume 266, Issue 4, 21 October 2010, Pages 569–572
Biological evidence against the panspermia theory
Massimo Di Giulio
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The following idea is analysed. Given that evolution on Earth seems to have passed through protocellular evolutionary stages of progenotes, this would appear to be incompatible with the panspermia theory because this observation would imply that the infection bringing life to the Earth started in these protocells, for which a low or null infective power is generally expected.
Progenote; tRNA split genes; Biosynthetic pathways on tRNAs; Evolutionary transitions; Coevolution theory of the genetic code
1. The panspermia theory
The panspermia theory, that is the possibility that life arrived on our planet transported by meteorites (lithopanspermia), was suggested in 1865 by the German physicist Hermann E. Richter (Raulin-Cerceau et al., 1998). In 1871, Lord Kelvin supported the same thesis that germs transported by meteorites might have infected the Earth (Thomson, 1871). In 1908, Arrhenius maintained that micro-organisms might have reached the Earth by means of an acceleration produced by stellar radiation pressure (radiopanspermia). A third possibility has also been explored, directed panspermia, which suggests that micro-organisms were deliberately transmitted to Earth by intelligent beings present on another planet (Crick and Orgel, 1973). There is some evidence supporting panspermia and some observations that might favour it. For instance, Gold (1992) maintains that if life were only restricted to the surface of planetary bodies then panspermia would be highly unlikely because there would not have been any protection against the harmful effects of cosmic rays. He, instead, claims that panspermia is a much more realistic possibility if there had been abundant life in the depths of planetary bodies and, therefore, there would have been a potential protection of micro-organisms offered by the rock for an interplanetary journey of life (Gold, 1992). Crick and Orgel (1973) cite the enrichment of molybdenum instead of chromium and nickel in current organisms as possible evidence of panspermia, since the existence of an organism ought not to depend on an extremely rare element. This suggestion has been criticised (Gualtieri, 1977). Planetary microcosms models of asteroids and meteorites also suggest that protoplanetary nebulae might support and disperse microorganisms (Mautner, 2002). Wickramasinghe (2004) has been one of the great supporters of the panspermia theory and has gathered considerable evidence in its favour (Wallis et al., 1992 and Sommer and Wickramasinghe, 2005). However, it seems to me that alongside the evidence presented by Wickramasinghe (2004), some of which seems truly weak, there is the view of Crick (1993) which seems to suggest that the implausibility of the RNA world might imply that life was born not on our planet but on a planet where there might have been conditions that were particularly favourable for the evolution of RNA and much less adverse than those that seem...
“Biologicaltheories of crime focus on the physiological, biochemical, neurological, and genetic factors that influence criminal behavior. However, such theories also stress the complex link between a person's biology and the broad span of social or environmental factors that sociological theories examine” (Denno, 2009).
Biological factors that contribute to crime are something neurological or chemical related, which is not to be confused with a genetic factor that is inherited from one parent. For example if a person has a predisposed gene that they got from the father side of the family. The father and grandfather were serial murderers and therefore the child is. Biological factors are different in that they are more internal. A good example is a person that has been in a bad car accident where they were thrown through the windshield and as a result suffered massive head trauma. His or her ability to reason thoroughly has been skewered and the portion of the brain that controls reason and morality are now affected or damaged. This person now commits criminal acts, acts violently towards others and has been detained by authorities on three separate occasions.
The injury is a contributor for this person’s action if previous review or research showed they had symptoms prior. We must also consider the biochemical aspects that affect...
...BiologicalTheories of Aging
Human Growth and Development
Aging is a biological phenomenon all the living things are undergoing. We are not sure about anything in the world except the aging. We are approaching getting nearer to the death from the time of the birth onwards. No living thing in the world has the ability to defeat death as it occurs sometimes naturally and sometimes accidently. Aging has different dimensions like physical, psychological, and social. There are many biologicaltheories with respect to aging. Simple Deterioration, Non-programmed Aging and Programmed Aging, Autoimmunity theory, Free radial theory, Telomerase Theory of Aging etc are some of them. This paper briefly explains some of the biologicaltheories of aging mentioned above.
Aging: Simple Deterioration Theory/ Wear and tear theory
Simple Deterioration Theory argues that Aging is the accumulative result of universal deteriorative processes such as oxidation, molecular damage, wear and tear, or accumulation of adverse byproducts (Goldsmith, p.3). Even though man and machine are two entirely different things, both of them have certain similarities in their functioning. No machine is able to function more than particular period of time because of the wear and tear due to continuous...
...Panspermia: A theory of survival of life on earth
Earth is 4.5 billion year old as supported by radiometric dating, and it’s history tells us some disturbing tales of survival of life on earth. For first half of its lifetime large asteroids were bombarding the planet every few million years, and then most violent impacts vaporized the oceans and melted the surface rock. Each such impact would have sterilized the planet for thousands of year. A few thousand years after such an impact, vapours would condense and earth would again become habitable. Surprisingly, if this is true then on the other side we know from the fossil records that bacteria were evolving in the same period. Then the question arises, how were bacteria evolving in the period if their kind became extinct after every few million years? Whether it was some devil’s curse or some self-fulfilling prophecy? However, answer lies in Panspermia.
So what is Panspermia? Panspermia is the speculation that life exists all through the Universe; disseminated by meteoroids, space rocks, comets, planetoids and furthermore by shuttle as unintended tainting by microorganisms. Moreover, Panspermia is a theory suggesting that minute life structures that can survive the impacts of space, such as, extremophiles, get caught in debris that launches out into space after crashes in the middle of planets and little solar system bodies...
...Evidence for and against secularisation
-evidence that religious practice is declining:
-in the UK membership of Christian Churches has declined since the 70s, however membership levels of Buddhist, Hindu, Jewish and Muslim religions has increased
-attendances of services has declined in Christian Churches
-civil marriage services have increased, religious marriages and baptisms have declined.
Wilson looked at these figures and argues that secularisation is happening
-levels of disengagement- church moving away from the state- high levels of disengagement shows that secularisation is happening, in Britain there has been disengagement over the last 200 years, the Monarch is no longer the active leader of the Church of England, but not complete disengagement as there are Bishops in the House of Lords and the Queen is a symbolic leader of the CofE, and there is compulsory religious education in secondary state schools. However in France they are totally disengaged they are not even allowed to wear religious symbols to school and they are not taught R.S, could be argued that France is secularised. However in Iran there is a Theocracy- so total engagement and therefore they are not secularised.
-millions have dropped out of mainstream religions over the last few years, although people are joining NRM the net movement is decreasing.
Secularisation from within- Herberg religious organisation have become less...
...Biologicaltheories of crime causation adhere to the principle that many behavioral predispositions, including aggression and criminality are constitutionally or physiologically influenced and inherited of the first basic principles of biologicaltheories is the mind and locus of personality which is the organ brain. The brain is the organ of behavior. We have the basic determinants of human behavior passed on from generation to generation. Human behavior and traits are genetically based to a considerable degree. Gender and racial differences in rates and type of criminality may be at least partially resulting of biological differences between sexes and between racially distinct groups. Much of human conduct is fundamentally rooted in instinctive behavior responses. Bi-logical roots of human conduct have become increasing disguised. Some human behavior is the result of biological propensities inherited from more primitive developmental stages in the evolutionary process. There is the interplay of hereditary, biology and the social environment provides the consideration of crime. I think it will help understand the action better and who might have these specific biological traits but as for a full understanding of criminality it will not help because there is a lot more to consider then just biology alone. The types of crimes related to aggression, rape, murder more...
...Two important personality theories are the biologicaltheory and the humanistic theory. The biologicaltheory is based on the premise that all people inherit their characteristics from their family. This theory basically contends that people do not have control over their behaviors because they are genetically pre-determined. The humanistic theory, on the other hand, is based on the premise that each person has free will to control their actions. This theory does not go along with the idea that behaviors are pre-determined by genetics, but chosen by the individual. These two theories have created debates between psychologists for many yearsHans j. Eysenck, Ph.D., D.Sc., who developed the biologicaltheory, is one of the world's most cited psychologist. He is a pioneer in the use of behavior therapy as well as research in personality theory and measurements. The biologicaltheory has to do with his findings that individual differences in personality are biology based. This was based on his theory that there are three dimensions of personality (super factors). These dimensions of personality were extraversion-introversion, neuroticism, and psychoticism. Eysenck also went a step farther in pointing out the results of many studies indicating that genetics...
Dispositional vs. BiologicalTheory
September 15, 2014
Dispositional vs. BiologicalTheory
Dispositional personality theories are quite different from biological personality theories. The two will be compared and dissected in this article. The Big Five Personality Test will also be analyzed and how it is used to study personality will be examined.
Dispositional personality theories contend that each person per certain stable, long lasting dispositions. These dispositions make a person display certain emotions, attitudes, and behaviors. These dispositions appear in many different kinds of situations, which lends the belief that people behave in predictable ways even when they are in different situations. The theory also states that each person has a different set of dispositions, or that their sets of dispositions have different strengths which assembles a unique pattern.
There are two different types of dispositional theories, type and trait theories. Type theories assign people to different categories. These categories depend on the individual’s temperament. Hippocrates and Galen suggest temperament is based on body fluids (which sounds a bit outlandish). Blood is said to represent the sanguine temperament. This is a person who is warmhearted, optimistic, and...
...BiologicalTheories and Criminal Behavior
Biologicaltheories address deviant behavior as a relationship between biological factors, and social norms in respect to crime. The theories address behavior of an individual based upon his or her biological impact. Schmalleger, (2008) points out a connection to social environments and the impact upon human behavior. The connection has validity because of human thoughts and activities are constantly flowing through the brain providing an impact relating to behavior. Researchers base biologicaltheories on flaws relating to heredity, dysfunction of the brain’s neurotransmitters, injuries, trauma, or abnormalities involving the brain affecting behavior (Raine, 2002).
Brain development is a biologicaltheory providing information connecting damage of the frontal lobes located in the brain’s cerebrum to criminal behavior. The brain is similar to a computer sending messages to the body and when the messages cannot be delivered it is because of a dysfunction that has occurred in the brain. The frontal lobes and the limbic system are two of the major areas of the brain involving behavior. The frontal lobes are responsible for reasoning, problem solving, and emotions (Allen & Harper, 2010). The limbic system contains electrical circuitry controlling emotions and motivation (Allen &...