Chain 3

From Chains of Reason

Life on Earth evolved by natural selection.

Link 1

Premise 1

There is slight, random variation in the hereditary traits of the members of any species of plant or animal.

Premise 2

A plant or animal's prospects of surviving and reproducing are affected by the nature of its traits.

Conclusion

Of the slight, random variations in hereditary traits among the members of any species of plant or animal, some will be more conducive to survival and reproduction than others. »

Link 2

Premise 1

 » Of the slight, random variations in hereditary traits among the members of any species of plant or animal, some will be more conducive to survival and reproduction than others.

Premise 2

In the competition between members of any species of plant or animal for finite resources and mates, the more conducive an hereditary trait variation is to survival and reproduction the more likely it is to pass into the next generation, and at the expense of those variations of the same trait which are less conducive to survival and reproduction.

Conclusion

Of the slight, random variations in hereditary traits among the members of any species of plant or animal, some will tend, in a non-random way, to become increasingly common in the population with each new generation, at the expense of other variations of the same trait. »

Link 3

Premise 1

 » Of the slight, random variations in hereditary traits among the members of any species of plant or animal, some will tend, in a non-random way, to become increasingly common in the population with each new generation, at the expense of other variations of the same trait.

Premise 2

The constant occurrence of slight, random mutations within each generation of any species of plant or animal ensures that there is a constant supply of new slight, random variation in the hereditary traits of the members of each species.

Conclusion

Any species of plant or animal can evolve over generations from less complex forms as the result of the non-random establishment, and accumulation, in the population of slight, random variations in hereditary traits among the members of the species. »

Link 4

Premise 1

 » Any species of plant or animal can evolve over generations from less complex forms as the result of the non-random establishment, and accumulation, in the population of slight, random variations in hereditary traits among the members of the species.

Premise 2

Evidence from fossils indicate that today’s species of plants and animals have evolved over geological time from less complex forms.

Conclusion

Today’s species of plants and animals have evolved over geological time from less complex forms as the result of the non-random establishment, and accumulation, in the population of slight, random variations in hereditary traits among the members of each species. »

Link 5

Premise 1

 » Today’s species of plants and animals have evolved over geological time from less complex forms as the result of the non-random establishment, and accumulation, in the population of slight, random variations in hereditary traits among the members of each species.

Premise 2

According to the theory of evolution by natural selection, today’s species of plants and animals have evolved over geological time from less complex forms as the result of the non-random establishment, and accumulation, in the population of slight, random variations in hereditary traits among the members of each species.

Conclusion

Life on Earth evolved by natural selection.

• see also: [show][hide]

External links

• Natural selection - Wikipedia article
• Evolution - Wikipedia article