The Struggle For The Struggle For ExistenceExistence

The Revolutionary idea of The Revolutionary idea of Evolution in determining Evolution in determining

species diversificationspecies diversification

History of Evolution

Lamarck published a theory of evolution in 1809 Lamarck thought that species arose continually

from nonliving sources. These species were initially very primitive, but increased in complexity over time due to some inherent tendency.

This type of evolution is called orthogenesis.

Orthogenesis continued

an organism's acclimation to the environment could be passed on to its offspring; species never go extinct

for example, he thought proto-giraffes stretched their necks to reach higher twigs. This caused their offspring to be born with longer necks.

This proposed mechanism of evolution is called the inheritance of acquired characteristics

Who might like this idea for structuring society?

Darwin ObservedDarwin Observed

Variability exists within a given speciesVariability exists within a given species

Variant traits may be passed on/inheritedVariant traits may be passed on/inherited

In this "struggle for existence", variants In this "struggle for existence", variants that were slightly better suited to the that were slightly better suited to the environment would be more likely to environment would be more likely to survive survive

This does *NOT* mean “Survival of the This does *NOT* mean “Survival of the Fittest”Fittest”

Big Damn Digital Post It NoteBig Damn Digital Post It Note

Darwin Never Said

Survival of the Fittest

Variation of Traits passed on to population

Populations Evolve; Not Individuals A population is a collection of individuals

which have some distribution of traits:

““I have called this principle, by which each slight I have called this principle, by which each slight variation, if useful, is preserved, by the term variation, if useful, is preserved, by the term Natural SelectionNatural SelectionIt is not the strongest of the species that survives, It is not the strongest of the species that survives, nor the most intelligent, but the one most nor the most intelligent, but the one most responsive to changeresponsive to changeIntelligence is based on how efficient a species Intelligence is based on how efficient a species became at doing the things they need to survivebecame at doing the things they need to surviveIn the survival of individuals and species, during In the survival of individuals and species, during the constantly-recurring struggle for existence, we the constantly-recurring struggle for existence, we see a powerful and ever-acting form of selection.”see a powerful and ever-acting form of selection.”

Darwin’s Says

One MoreOne More

I think it inevitably follows, that as new I think it inevitably follows, that as new species in the course of time are formed species in the course of time are formed through natural selection, others will through natural selection, others will become rarer and rarer, and finally extinct. become rarer and rarer, and finally extinct. The forms which stand in closest The forms which stand in closest competition with those undergoing competition with those undergoing modification and improvement will naturally modification and improvement will naturally suffer most.suffer most.

Final Exam QuestionsFinal Exam Questions

Is Natural Selection inconsistent Is Natural Selection inconsistent with the idea of the Mechanical with the idea of the Mechanical Universe? (what would Descartes Universe? (what would Descartes Say?)Say?)

Darwin – Origin of Darwin – Origin of Species -1859Species -1859

Mechanism for Evolution is Natural Mechanism for Evolution is Natural Selection Selection

New variants continually arose within New variants continually arose within populations populations Darwin observes this but Darwin observes this but does not understand what mechanism does not understand what mechanism causes thiscauses this

Numerous instances of selecting the Numerous instances of selecting the variant (due to higher survival variant (due to higher survival probability) probability) slowlyslowly leads to species leads to species modification/diversificationmodification/diversification

Favorable Variations Drive Favorable Variations Drive EvolutionEvolution

Darwin: If certain variants will be Darwin: If certain variants will be preserved over time over other preserved over time over other variants then that population will variants then that population will change over time in their change over time in their composition. This is evolution by composition. This is evolution by natural selection.natural selection.

But Darwin does not understand how But Darwin does not understand how the variations of traits are generated the variations of traits are generated in the first placein the first place

Natural Selection Random pairings of Gene Pool/traits (Darwin

does not know this) Each pairing has a different survival

probability within some Ecosystem If ecosystem is stable the end results is a

distribution of most probable values (slow vs fast rabbits)

This statistical process takes a large number of generations to manifest itself

Statistical types of selection

In complex creatures, the variation of traits may be quite large make it much harder to discern the average set of traits from one individual creature.

Selection as “Deficiency Correction” advancement of the mean The most common action of natural

selection is to remove unfit variants as they arise (randomly) via mutation. In other words, natural selection usually prevents unfit genes from increasing in frequency in the gene pool.

Advancement of the Mean is dangerous and erroneous concept

Evolution is not an optimization process – there is never enough time for that – so why do we pretend that is natural optimization instead of natural selection?– Supports the Social Darwinist Agenda that society

can be engineered – Takes nature out of statistical equilibrium if it can

optimize to produce the Master Race

Each Black Dot in each distribution represent individuals that die out before passing on their genes

Stabilization: Extreme ends of the distribution are disfavored. Moves every individual closer to the average state.

Directional: What you think is evolution – removes the deficient

Disruptive: Individuals with average traits are disfavored. Better leads to species diversification.

Mutations will affect largest number of individuals (i.e. average). Leads to development of new species and arguably is the process that happens on Earth

Darwin Abused: Survival of the Darwin Abused: Survival of the FittestFittest

Hebert Spencer: This survival of the fittest, which I have here sought to express in mechanical terms, is that which Mr. Darwin has called "natural selection” or the preservation of favored races in the struggle for life

Social Engineering will now use this new scientific theory of evolution via adaptation as the scientific basis on which to engineer society.

The Aberrated View of The Aberrated View of SpencerSpencer

Spencer quickly adapted Darwinian ideas to Spencer quickly adapted Darwinian ideas to his own ethical theories. The concept of his own ethical theories. The concept of adaptation allowed him to claim that the adaptation allowed him to claim that the rich and powerfulrich and powerful were better were better adaptedadapted to to the social and economic climate of the time, the social and economic climate of the time, and the concept of natural selection allowed and the concept of natural selection allowed him to argue that it was him to argue that it was natural, normal, natural, normal, and proper for the strong to thrive at and proper for the strong to thrive at the expense of the weakthe expense of the weak. After all, he . After all, he claimed, that is exactly what occurs in claimed, that is exactly what occurs in naturenature every day. every day.

Social DarwinismSocial Darwinism

Not only was survival of the fittest natural, but it Not only was survival of the fittest natural, but it was also morally correct. was also morally correct.

it was morally incorrect to assist those weaker it was morally incorrect to assist those weaker than oneself, since that would be promoting the than oneself, since that would be promoting the survival and possible reproduction of someone survival and possible reproduction of someone who was fundamentally unfit. who was fundamentally unfit.

The American eugenics movement was relatively The American eugenics movement was relatively popular between about 1910-1930, during which popular between about 1910-1930, during which 24 states passed sterilization laws and Congress 24 states passed sterilization laws and Congress passed a law restricting immigration from certain passed a law restricting immigration from certain areas deemed to be unfit areas deemed to be unfit

Summary

Evolution requires genetic variation Genetic variation is caused by gene mutation Mutation is continuously occurring within a

species Natural selection operates on this variation These variations are largely random Most adaptable variations survive independent

of their “Fitness”