Evolution
...
1.2.2 Mutation
1.3 Differential
survival of traits
1.3.1 Natural selection
... do not affect the organism's chances of
survival in its natural environment and can accumulate ... very large scale mutation.
Differential
survival of traits
While mutation can create new ...
Human
... societies, ritual is considered essential for
survival as it wins the favor of the spirits of one's ... that they form, both for individual and group
survival and for the preservation and development of ... variability
environmentalism
space and
survival
world population , world hunger
human ...
Molecular evolution
... do not affect the organism's chances of
survival in its natural environment and can accumulate ...
There are four known processes that affect the
survival of a characteristic; or, more specifically, the ... and fertility. Differential mortality is the
survival rate of individuals before their reproductive ....
Natural selection
... well particular traits of organisms can serve the
survival and reproduction of the organism; organisms ... in such conditions, or in any circumstance where
survival is determined by ecology more than by the ... the offspring which manifest it better suited to
survival or to successful reproduction, that offspring and ...
Apoptosis
... all tissue in multicellular animals depends on continuous receipt of
survival signals. In the case of T cells, as they develop and mature in the thymus, the
survival signal depends on their capability to engage foreign antigen. Those that ...
Cancer
... higher cancer rates than black infants for most cancer types. Relative
survival for infants is very good for neuroblastoma, Wilms' tumor and ... JG, Linet M, Tamra T, Young JL, Bunin GR (eds). Cancer Incidence and
survival among Children and Adolescents: United States SEER Program 1975-1995, ...
Edward's syndrome
... of these infants are able to overcome these initial difficulties.
The
survival rate for Edward's Syndrome is still incredibly low. Only 5 - 10% of ... withheld from these children, it is also difficult to determine what the
survival rate or prognosis would be for the condition if they were treated with the ...
Gene
... with the same gene, the death of an individual may enhance the overall
survival of the gene. This is the basis of the selfish gene view, popularized by ... answer to the question "what is the meaning of life?" may be "the
survival and perpetuation of ribonucleic acids and their associated proteins".
...
Muller's ratchet
... or its host may have an advantageous mutation -- that will lead to their
survival despite the deleterious mutation. Because there is no possibility for ... a good copy of the gene. If the other mutation is advantageous, their
survival means that the deleterious mutation persists. These deleterious mutations ...
Red Queen
... yet they bear no offspring directly and generally contribute little to the
survival of offspring. In addition, males and females must find each other to mate, and sexual selection often favors traits that reduce the
survival of organisms. Thus, sex is highly inefficient.
One possible explanation ...
Antibiotic
... be much less than that of the original population, since they have descended from those few organisms which survived the original treatment. This
survival often results from an inheritable resistance to the compound, which was infrequent in the original population but is now much more frequent in the ...
Reproduction
... to reproduce; on the other hand, animals with many offspring do not need to spend parental energy on nurturing, allowing more energy to be devoted to
survival and more breeding.
These two strategies are known as K-selection (few offspring) and r-selection (many offspring). Which strategy is favoured ...
Ernst Haeckel
... that have not been found and almost certainly did not exist. His concept of recapitulation has been disproven. Haeckel did not support Darwin's "
survival of the fittest ", rather believing in a Lamarckian inheritance of acquired characteristics. On top of picking several wrong concepts to champion, ...
Genetic drift
... in populations
Drift can have profound and often bizarre effects on the evolutionary history of a population. These effects may be at odds with the
survival of the population.
In a population bottleneck , where the population suddenly contracts to a small size and then grows again to a large ...
Insulin
... in some forms of diabetes mellitus . Patients with Type 1 diabetes mellitus depend on exogenous insulin (injected subcutaneously) for their
survival because of an absolute deficiency of the hormone; patients with Type 2 diabetes mellitus have either relatively low insulin production or insulin ...
Life
... example, see kin selection for information about one way by which non-reproducing individuals can still enhance the spread of their genes and the
survival of their species.)
Note also that the two cases of fire and stars fitting the definition of life can be simply remedied by defining metabolism in a ...
Malaria
... dehydrogenase deficiency (G6PD). It protects against malaria caused by Plasmodium falciparum as the presence of this enzyme is critical to
survival of these parasites within red blood cells.
It is thought that humans have been affected by malaria for about 50,000 years, and several human genes ...
Metapopulation
... emphasis the importance of connectivity between seemingly isolated populations. Although no one population may be able to guarantee the long-term
survival of a given species, the combined effect of many populations may be able to do this.
The most important contributer to metapopulation theory is ...
Mutational meltdown
... W. Gabriel (1993). The mutational meltdown in asexual populations. J. Hered. 84: 339-344.
M. Lynch and W. Gabriel (1990). Mutation load and the
survival of small populations. Evolution 44: 1725-1737.
...
Nutrition
... supply of preserved food seemed to boost the sailor’s resistance to the illness, and fewer died. The existence of parts of food essential for
survival had been discovered. Other so-called vitamins were discovered through the effect of their absence on people’s health, and increasingly the role ...
Origin of life
... in our solar system would lend significant credence to this theory. He also noted that a trickle of food from a deep, unreachable, source promotes
survival because life arising in a puddle of organic material is likely to consume all of its food and become extinct.
"Primitive" extraterrestrial life ...
Reproduction
... to reproduce; on the other hand, animals with many offspring do not need to spend parental energy on nurturing, allowing more energy to be devoted to
survival and more breeding.
These two strategies are known as K-selection (few offspring) and r-selection (many offspring). Which strategy is favoured ...
Y chromosome
... mistakes - mutations - occur throughout all chromosomes, and the existence of some high-accuracy repair mechanism is known to be necessary for the
survival of the chromosome, and thus the species carrying the chromosome.
The primary repair mechanism is dependent upon the fact that all people receive ...