-
Welcome to Religious Forums, a friendly forum to discuss all religions in a friendly surrounding.
Your voice is missing! You will need to register to get access to the following site features:- Reply to discussions and create your own threads.
- Our modern chat room. No add-ons or extensions required, just login and start chatting!
- Access to private conversations with other members.
We hope to see you as a part of our community soon!
Survival of the Fittest?
- Thread starter Sunstone
- Start date
Halcyon
Lord of the Badgers
To quote from one of my text books;
"Fitness. For a start, relative lifetime reproductive success, which includes the probability of survival to reproduce. In certain situations, other measures are more appropriate. The most important modifications to the definition include the inclusion in the definition of the effects of age-specific reproduction, and of fluctuations of density dependance. "
Ref; Evolution (an introduction) by S. C. Sterns and R. F. Hoekstra.
"Fitness. For a start, relative lifetime reproductive success, which includes the probability of survival to reproduce. In certain situations, other measures are more appropriate. The most important modifications to the definition include the inclusion in the definition of the effects of age-specific reproduction, and of fluctuations of density dependance. "
Ref; Evolution (an introduction) by S. C. Sterns and R. F. Hoekstra.
From http://en.wikipedia.org/wiki/Survival_of_the_fittest
Survival of the fittest is a phrase which is a shorthand for a concept relating to competition for survival or predominance. Originally applied to economics by Herbert Spencer, Spencer drew parallels with Charles Darwin's theories of evolution by what Darwin termed natural selection. The phrase is essentially a metaphor and is often felt to be unhelpful - biologists almost exclusively use natural selection in preference. Some have argued that it is a tautology, since if "fitness" is measured in terms of survival, the phrase becomes "survival of the survivors". Others argue that it is not a tautology, but a biological definition of "fitness".
Natural selection is the process by which variants displaying favorable or deleterious traits end up producing more or fewer progeny relative to other individuals of the same population. Biological variants within a population tend to produce more or less progeny relative to other variants in the same population, if they happen to perform/function better or worse than the other variants. When the causes of the superior performances are heritable and become enriched in the next generation so that more variants of the superior type are observed in the next generation, one speaks of adaptive evolution by natural selection. Evolution, therefore, can involve changes not driven by natural selection; and natural selection is not sufficient for evolutionary change to take place, let alone for adaptive evolutionary change (since the latter requires that the selected traits be heritable). In general, however, adaptive evolution requires natural selection because the possibility that favorable traits become more frequent across generations due to random fluctuations in trait occurrence, is negligible (see genetic drift).
It would seem therefore that 'adaptive evolution' is also a factor.
Survival of the fittest is a phrase which is a shorthand for a concept relating to competition for survival or predominance. Originally applied to economics by Herbert Spencer, Spencer drew parallels with Charles Darwin's theories of evolution by what Darwin termed natural selection. The phrase is essentially a metaphor and is often felt to be unhelpful - biologists almost exclusively use natural selection in preference. Some have argued that it is a tautology, since if "fitness" is measured in terms of survival, the phrase becomes "survival of the survivors". Others argue that it is not a tautology, but a biological definition of "fitness".
Natural selection is the process by which variants displaying favorable or deleterious traits end up producing more or fewer progeny relative to other individuals of the same population. Biological variants within a population tend to produce more or less progeny relative to other variants in the same population, if they happen to perform/function better or worse than the other variants. When the causes of the superior performances are heritable and become enriched in the next generation so that more variants of the superior type are observed in the next generation, one speaks of adaptive evolution by natural selection. Evolution, therefore, can involve changes not driven by natural selection; and natural selection is not sufficient for evolutionary change to take place, let alone for adaptive evolutionary change (since the latter requires that the selected traits be heritable). In general, however, adaptive evolution requires natural selection because the possibility that favorable traits become more frequent across generations due to random fluctuations in trait occurrence, is negligible (see genetic drift).
It would seem therefore that 'adaptive evolution' is also a factor.