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The fundamental statement of '''natural selection''' is that heritable traits which are beneficial will tend to become more numerous in successive generations, while heritable traits which are harmful will tend to become more scarce. The traits are defined to be beneficial if they become more numerous in successive generations. This principle is general, and applies to any system of individuals which reproduce; it is most commonly applied to systems of living organisms.  

The fundamental statement of '''natural selection''' is that heritable traits which are beneficial will tend to become more numerous in successive generations, while heritable traits which are harmful will tend to become more scarce. The traits are defined to be beneficial if they become more numerous in successive generations. This principle is general, and applies to any system of individuals which reproduce; it is most commonly applied to systems of living organisms.  

It is sometimes summarized by the slogan, ''survival of the fittest'', where the "fittest" are the organisms which leave the most offspring. This means that "fitness" is determined by the environment; for example, a penguin is very good at producing offspring when it lives in Antarctica, but wouldn't be so good if it lived in the Sahara.  

It is sometimes summarized by the slogan, ''survival of the fittest'', where the "fittest" are the organisms which leave the most offspring. This means that "fitness" is determined by the environment; for example, a penguin is very good at producing offspring when it lives in Antarctica, but wouldn't be so good if it lived in the Sahara.  

Natural selection is often thought of as being synonymous with [[Theory of evolution|evolution]],<ref>For example, a draft [[New Zealand]] science curriculum confuses the two.  Lamb, Andrew, [http://www.creationontheweb.com/content/view/5047/ Evaluating an evolutionary science curriculum], 14th April, 2007 (Creation Ministries International).</ref> although they are distinct concepts, and most [[creationism|creationists]] accept that natural selection is a real, observed, process.

Natural selection is often thought of as being synonymous with [[Theory of evolution|evolution]],<ref>For example, a draft [[New Zealand]] science curriculum confuses the two.  Lamb, Andrew, [http://www.creationontheweb.com/content/view/5047/ Evaluating an evolutionary science curriculum], 14th April, 2007 (Creation Ministries International).</ref> although they are distinct concepts.

 

Microevolution and natural selection are accepted to occur by all creationists,<ref name="nat">Numbers RL. Ironic Heresy: How Young-Earth Creationists Came to Embrace Rapid Microevolution by Means of Natural Selection. In: Lustig A, Richards RJ, Ruse M, eds. Darwinian Heresies. Cambridge University Press; 2004:84-100.</ref> but macroevolution and the limits of natural selection is what is usually disputed.<ref>[https://answersingenesis.org/evolution/?srsltid=AfmBOopLgbKLuo1T0WUtyPAE_oC6BsxXISw-TLyKw37AXTXDbMH77y-v Evolution - Answers in Genesis]</ref><ref name="nat" />

 

Alfred Russel Wallace, a naturalist, was the co-discoverer of natural selection along with [[Charles Darwin]]. Wallace eventually came to believe that nature exhibited design and purpose with evolution.<ref>Alfred Russel Wallace. 1911. [https://archive.org/details/worldoflifemanif00walliala The World of Life: A Manifestation of Creative Power, Directive Mind and Ultimate Purpose]</ref>  His works on natural selection were around in the 1850s and some works on the uniqueness of man occurred in the 1860s.<ref name="wallacenat">Alfred Russel Wallace. [https://wallace-online.org/converted/pdf/1895_NaturalSelection_S725%5B2d%5D.pdf Natural Selection and Tropical Nature: Essays on Descriptive and Theoretical Biology] important works on natural selection: "The Law which has Regulated the Introduction of New Species" (1855) and of course "On the Tendency of Varieties to Depart Indefinitely from the Original Type" (1858); on the the limits on natural selection and man see "Limits of Natural Selection as Applied to Man" (1869)</ref> His views challenge the Darwinist view of evolution and allow for a an overlap between design, intelligence, purpose with natural selection and evolution.<ref>Flannery, M.A. Alfred Russel Wallace’s Intelligent Evolution and Natural Theology. Religions 2020, 11, 316. https://doi.org/10.3390/rel11060316</ref><ref>Flannery, Michael A. 2011. Alfred Russel Wallace’s Theory of Intelligent Evolution: How Wallace’s World of Life Challenged Darwinism, rev ed. Riesel: Erasmus Press</ref>

 

 

The theory of natural selection was published by naturalist [[Darwin, Charles|Charles Darwin]] in his book ''[[The Origin of Species|On The Origin of Species by Means of Natural Selection or The Preservation of Favored Races in the Struggle for Life]]'' (1859) and also by Alfred Russel Wallace in his paper ''On the Tendency of Species to form Varieties; and on the Perpetuation of Varieties and Species by Natural Means of Selection'' (1858). Charles Lyell and Joseph Dalton Hooker decided on a joint publication at the Linnean Society of London in 1858 of Wallace's paper together with an extract from Darwin's 1844 essay and his letter to Asa Gray and summarized:<ref>Charles Darwin, Alfred Wallace, On the Tendency of Species to form Varieties; and on the Perpetuation of Varieties and Species by Natural Means of Selection, Zoological Journal of the Linnean Society, Volume 3, Issue 9, August 1858, Pages 45–62, https://doi.org/10.1111/j.1096-3642.1858.tb02500.x</ref><ref>[https://www.biodiversitylibrary.org/page/2311239#page/127/mode/1up 1858 Online link to Summary by Joseph Hooker and Charles Lyell]]</ref>

 

The gentlemen having, independently and unknown to one another, conceived the same very ingenious theory to account for the appearance and perpetuation of varieties and of specific forms on our planet, and both fairly claim the merit of being original thinkers in this important line of inquiry; but neither of them having published his views, though Mr. Darwin has for many years past been repeatedly urged by us to do so, and both authors having now unreservedly placed their papers in our hands, we think it would best promote the interests of science that a selection from them should be laid before the Linnean Society. Taken in the order of their dates, they consist of:—

 

 

 

 

* [http://www.equip.org/articles/is-darwinism-atheistic- Is Darwinism Atheistic? An Examination of the Beliefs and Practices of Charles Darwin]

</ref> Darwin was a [[weak atheism|weak atheist]]/[[agnosticism|agnostic]] (see: [http://www.conservapedia.com/Charles_Darwin#Religious_Views_of_Charles_Darwin religious views of Charles Darwin) ].<ref>

* [http://www.creation.com/content/view/1877 Darwin's real message: have you missed it?]

* Barrett, Paul H. ''Darwin on Man'' 1974:276

*[http://creation.com/charles-darwins-illegitimate-brainchild Darwin’s Illegitimate Brainchild: If You Thought Darwin’s Origin Was Original, Think Again! by Russell Grigg]

*[http://www.bradburyac.mistral.co.uk/dar0.html Charles Darwin - The Truth]</ref> Darwin's theory attempted to explain the origin of the various kinds of plants and animals via the process of ''[[natural selection]]'' or "survival of the fittest".

 

One major difference between Darwin and Wallace is that Wallace argued that nature exhibited design and purpose with natural selection and evolution.<ref>Alfred Russel Wallace. 1911. [https://archive.org/details/worldoflifemanif00wallialaThe World of Life: A Manifestation of Creative Power, Directive Mind and Ultimate Purpose]</ref> Wallace's view of evolution allowed for a an overlap between design, intelligence, purpose with natural selection and evolution.<ref name="intelligent evolution" />

==General Requirements==

==General Requirements==

==Variation and Randomness==

==Variation and Randomness==

Natural selection becomes interesting when there is the possibility of random variation in the [[duplication]] of individuals--in other words, when an individual is copied, the copy may be slightly different from the original.  It is important to note that, as stated above, the ''mechanism'' for this variation is not explained or even taken into account by natural selection.  All that matters is that there is ''some'' process that produces variation.  In this case, some of the offspring of an individual will be better (where "better" is defined as "more likely to successfully reproduce"--one can think of it as scoring higher on an evaluation) and some will be worse.  The higher-scoring offspring will soon come to dominate the population, and over successive generations the average score will also rise.

Natural selection becomes interesting when there is the possibility of random variation in the [[duplication]] of individuals—in other words, when an individual is copied, the copy may be slightly different from the original.  It is important to note that, as stated above, the ''mechanism'' for this variation is not explained or even taken into account by natural selection.  All that matters is that there is ''some'' process that produces variation.  In this case, some of the offspring of an individual will be better (where "better" is defined as "more likely to successfully reproduce"—one can think of it as scoring higher on an evaluation) and some will be worse.  The higher-scoring offspring will soon come to dominate the population, and over successive generations the average score will also rise.

==Role in Life Sciences==

==Role in Life Sciences==

Here is an example of how an engineer might use an algorithm that is analogous to the combination of mutation and natural selection in the evolution of organisms.

Here is an example of how an engineer might use an algorithm that is analogous to the combination of mutation and natural selection in the evolution of organisms.

An engineer starts with 10,000 different sets of plans for a hydroelectric dam.  His dam must complete two basic tasks: it must hold back a lake with minimal flooding of the surrounding area, and it must maximize power generation.  The intrinsic worth of a dam is determined by how well it completes these tasks; a dam which produces 100 kW of electricity while only raising water levels 2 feet is superior to one which produces 10 kW of electricity while raising water levels 5 feet.

An engineer starts with 10,000 different sets of plans for a hydroelectric dam.  His dam must complete two basic tasks: it must hold back a lake with minimal flooding of the surrounding area, and it must maximize power generation.  The intrinsic worth of a dam is determined by how well it completes these tasks; a dam which produces 100&nbsp;kW of electricity while only raising water levels 2 feet is superior to one which produces 10&nbsp;kW of electricity while raising water levels 5 feet.

In our simplified example, let us assume that the design of a dam is based on just a few numerical parameters: height, width, thickness, concrete mixture, hydroelectric turbine size, curvature, etc.  After evaluating all the plans, the engineer picks the 100 best and discards the rest.  He then copies each of these plans 100 times.  When copying, the engineer randomly introduces minor differences: say he rolls a die each time he copies a design parameter; if he rolls a six, he then changes that parameter by 1%, flipping a coin to determine if he will increase or decrease the parameter.

In our simplified example, let us assume that the design of a dam is based on just a few numerical parameters: height, width, thickness, concrete mixture, hydroelectric turbine size, curvature, etc.  After evaluating all the plans, the engineer picks the 100 best and discards the rest.  He then copies each of these plans 100 times.  When copying, the engineer randomly introduces minor differences: say he rolls a die each time he copies a design parameter; if he rolls a six, he then changes that parameter by 1%, flipping a coin to determine if he will increase or decrease the parameter.

Once he has finished copying, he will have 10,000 more plans, most of them very similar to the original 100 but with some small differences.  He then evaluates these 10,000 plans again, picks the best 100, and copies them again, introducing random "errors" in the same way.  After completing this process several thousand times, the engineer has 10,000 plans, all of which perform excellently.  He picks the best of them and thus has an excellent design, without ever doing any real "design" himself.

Once he has finished copying, he will have 10,000 more plans, most of them very similar to the original 100 but with some small differences.  He then evaluates these 10,000 plans again, picks the best 100, and copies them again, introducing random "errors" in the same way.  After completing this process several thousand times, the engineer has 10,000 plans, all of which perform excellently.  He picks the best of them and thus has an excellent design, without ever doing any real "design" himself.

Note that this engineer need not be conscious of the overall goal--he is just applying a simple algorithm over and over.  Indeed, the engineer need not be conscious of anything at all--his task could be performed automatically and without sentience or intelligence.  Note also that the final plan may be very different from any of the original plans.

Note that this engineer need not be conscious of the overall goal—he is just applying a simple algorithm over and over.  Indeed, the engineer need not be conscious of anything at all—his task could be performed automatically and without sentience or intelligence.  Note also that the final plan may be very different from any of the original plans.

==Local and Non-Local Improvement==  

==Local and Non-Local Improvement==

The above section illustrates how natural selection and random variation can combine to create improved individuals.  However, it is important to note that there is no long-term planning involved in natural selection.  This means that all changes must be locally beneficial in order to survive.  Essentially, no improvement can take place if a deterioration must take place first.  In order for a change to propagate to future "generations" of individuals, it must not be significantly harmful to ''any'' generation.

The above section illustrates how natural selection and random variation can combine to create improved individuals.  However, it is important to note that there is no long-term planning involved in natural selection.  This means that all changes must be locally beneficial in order to survive.  Essentially, no improvement can take place if a deterioration must take place first.  In order for a change to propagate to future "generations" of individuals, it must not be significantly harmful to ''any'' generation.

==References==

==References==

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[[Category:Biology]]

[[Category:Biology]]

[[Category:Genetics]]

[[Category:Genetics]]

[[Category:Evolution]]

[[Category:Evolution]]