what is darwins theory of evolution?

Answer 1

1) All life is related and has descended from a common ancestor.
2)Natural selection (survival of the fittest)- those who have better adaptations (are better adapted to the environment/ who have advantages over others) survive and reproduce, continuing their species. Stronger ones survive, weaker ones die off.
3) Evolution is a slow and gradual process.

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Answer 2

Darwin's theory is called natural selection. His theory is based on these ideas:
1. Organisms have more offspring than can possibly survive.
2. Offspring have variations--they are not all alike.
3. There's always competition for resources, for mates, for living space, to avoid being eaten, ...
4. The individuals that happen to have a variation that helps them survive when others do not are the ones who will get to reproduce the next generation. Their offspring are more likely to have the same favorable variation.
5. After many generations, the favorable variation is common in the population.

Answer 3

There is phenotype (physical appearance) and genotype (genetic make-up) of every species. However, even within a species, there is variation on phenotypic attributes. In humans, for example there is a variation on height, skin color, and much more.

What Darwin's theory on evolution suggests is that nature evolves species of animals by "selecting" the members in the particular species most fit to "survive and reproduce" in their environment. In reverse, through natural causes, nature kills those who are not fit to survive and reproduce in the respective environment. When this occurs, nature focuses on the phenotype of a species, not the genotype.

So, for illustration, if in our natural environment, being a midget had detrimental affects in being able to survive and reproduce, natural selection would take its course because those people would die and only the taller people would survive.

DO not confuse natural selection with super-natural causes; it is pure reasoning. If members of a species are vulnerable to being attacked and killed by another species, those members will naturally be defeated while the other members of the species live on. When the surviving members of the species group reproduce, their offspring will generally have their phenotypic attributes while the phenotypic attributes of the other members will be less common.

However, this gets very complicated when you bring into consideration "dominant alleles" and "recessive alleles." Alleles are what create the genotypic make-up of a species, and through reproduction both dominant and recessive alleles are passed on. Usually, an animal’s phenotype will reflect dominant alleles. However, recessive alleles will always show up at one point or another. From this, you can conclude that only if the phenotype that natural selection does not support is a reflection of dominant alleles will it be able to disappear over time. If it is a recessive allele that the phenotype reflects, however, the phenotypic attributes associated with that allele will always come up time and again and natural selection will kill that species-member.

Answer 4

Darwin presented his theory of evolution in his 1859 book "The Origin of Species." His basic idea was that of natural selection, which means that the organisms that are better fitted for survival will survive and will reproduce, and that organisms that are not well fit for their environments will eventually die out or adapt.

Answer 5

As many more individuals of each species are born than can possibly survive; and as, consequently, there is a frequently recurring struggle for existence, it follows that any being, if it vary however slightly in any manner profitable to itself, under the complex and sometimes varying conditions of life, will have a better chance of surviving, and thus be naturally selected. From the strong principle of inheritance, any selected variety will tend to propagate its new and modified form.

Answer 6

The theory of evolution by natural selection. Variation, leading to the differential survival of organisms over time. You may get much longer answers, but this about sums it up. Go here.

http://www.talkorigins.org
and here

http://www.aboutdarwin.com

Answer 7

random genetic variations and mutations which may cause one species to survive over another, and such variation may prove advantageous