Item 3
1 THE EVOLUTION OF LIVING
1.1 old theory about the origin of species
Fixism or creationism
is a theory proposed qe qe species do not change, but qe remain unchanged over time.
animal or plant species would be immutable, and can not be any change in them, and qe no kinship among them. (Karl von Linné)
Catastrophism
Cuvier, interpret the fossil qe qe was discovered in certain locations corresponded to remnants of organisms qe existido.Para had to explain this diversity, was qe develop the theory of ... . According to this theory, there was a catastrophe qe destroy existing species, so qe subsequent emergence of a creation of new species.
1.2 Evolution: Evolutionary theories
Transformism
Monet, Chevalier de Lamarck, with his comments came to conclusions quite contrary to fijismo.Se qe realized species traits seemed to change over the tiempo.Por qe, Lamarck's hypothesis is called transformations, noting qe species evolve to become each other.
is based on two points:
1. Function creates the organ.'s bodies have been trying to adapt to environmental conditions in viven.Desarrollo qe.
2. Adqiridos characters are inherited. adqiridos series of modifications are inherited by an individual throughout his life by his descendants.
Giraffe.
Darwin-Wallace
is based on the following principles:
1.Elevada reproductive capacity of living beings. The limitation of resources provides a struggle for existence
(racing, food, reproduce)
2.Variabilidad populations. Due to heritable characteristics of individuals, there is great variability between them.
Natural 3.Select. In a population, between individuals arises a struggle for survival, eliminating the most unfavorable and the fittest survive.
4.Especies evolve.'s Qe survive form the next generation and thus the changes are transmitted from generation to generation.
The theory of the evolution of Darwin-Wallace creates a bond of kinship between all living things.
Neo-Darwinism
stemmed from a synthesis between the selection theory of Darwin and Mendel's genetics. (Dobzhansky).
evolution is due to two fundamental facts:
1.Existencia a population genetic variability. ie, a large number of different genotypes, caused by mutations and genetic recombination during sexual reproduction.
2.Actuacion of natural selection and evolutionary basis. Tends to eliminate the population of genotypes less advantageous and allows for better adapted individuals.
1.3 New theory of evolution
Neutralism
natural selection is not pure chance but does qe qe varien the populations in which a particular mutated gene can be dispersed without any selective advantage.
(Motoo Kimura)
Rated or balancing between theory saltationism
qe poses the absence of intermediate steps in the fossil record is not due to incomplete qe, qe but sometimes evolution occurs in leaps. (Stephen Gould).