Monday, 20 June 2016

The "Evolution" of Darwin

The Evolution of Darwin

Darwin with Modification
Hence, both in space and time, we seem to be brought somewhat near to that great fact
– that mystery of mysteries – the first appearance of new beings on this earth.
Charles Darwin
Darwin
With Modification
In respect of the man and in honor of his publication of the book on his theory… Darwin did not call his theory, the theory of "evolution".  I don’t have problem using the word evolution is if it is being meant as the historical evidence of change over time. I use it in this way myself. You may think this is nit-picking, but sometimes the words we use distort people’s perception in unintended ways. By the way, I also have issues with the way the phrase “Survival of the Fittest” and even "Natural Selection" is used by some people. But that’s a whole other post in itself. See: Logic, Science and Theory

On the Origin of Species
by Means of Natural Selection

The only place where Charles Darwin uses the word “evolved” is in the last word of the last sentence of the last paragraph of the last chapter in The Origin Of Species. He knew the word, but clearly didn't use it for his theory. The word evolution, defines an unfolding, a directional development. Yet, Darwin never suggested there was a direction (or evolution) toward perfection or an ideal design. He only observed inherited change in the individuals of populations, over several generations. Explaining this process of change in populations and species over time,

Darwin's own words for his theory were Descent With Modification.
Descent
With Modification

The fact is, these words embody Darwin's insight more accurately than the popular word evolution. Darwin's theory postulates that there is no direction for change except that determined by the favorability or unfavorability brought on by the conditions and circumstances in nature. That the selection is natural, not chosen and as Darwin noted, over time, nature is always changing. Nature, the conditions in which you live determines success or failure for a form of life. To be preserved to go on into the future or perish. The changing conditions in nature drives the changes in the all the forms of life we see. So, these may be better words to keep this in mind and avoid misunderstanding what he meant.
Darwin had the idea for his theory in 1838 but did not publish his book for close to 20 years. It was first published on Thursday 24 November 1859. It is down to speculation as to why. However what is clear was that it took courage. In his time and society, especially with him to have studied Theology in his younger days, he must have know what reaction to expect when implications of what he was saying where known publicly. Courage to stand fast to the facts and evidence that led to his insight and the conviction (in the sense of a belief, held as proven) that led him to publish. He is to be admired as much for this courage, as the results of his work.

In his day, and with the available science, Darwin may not have been quite able to nail down the actual process of inheritance. He was pretty close in his guess that some "gemule" is passed on by both parents to the offspring. Although, it clear that even without the benefit of genetics, he did appear to have a powerful notion of the how inherited modifications of the descendants leads to diversity and speciation by a natural selection. A clear explanation for the variety seen in natural history. What is also clear...

Charles Darwin,
had an insight that greatly advanced our understanding of life.
THE 5 CONDITIONS IN WHICH NATURAL SELECTION TAKES PLACE

1. Life is not easy.
No matter the means to survive, you have to hustle to live.

Clearly, all the resources for living are not of infinite availability or supply. This creates a condition that Darwin called a struggle for existence. One must struggle in varying degrees with the conditions of the environment, such as heat, cold and the weather, as well as in varying degrees there are situations where one struggles in competition with other beings. However, there can be advantages in cooperating as well.

You must put forth some effort in order to live, eat and reproduce.
2. Bad Stuff happens. 
In order to maintain continuity of the lineage there must be an excess of offspring produced to offset natural and unexpected loss.

Life is a struggle and not everybody survives this struggle with enough offspring to continue their line.

Death, it happens. Predators, competition, old age and illness are vulnerabilities that could be more immediately fatal to the mal-adapted. And death comes not only to the ones unsuitable to the conditions. Sometimes it happens through no fault or defect or deficiency. Natural disasters like volcanoes, don't always seem to be so fussy who's in the way. There are no guarantees that even those in harmony or suitable to the living conditions are going to avoid failure to reproduce into the future due to stochastic events. Asteroids and dinosaurs.

Therefore, those that reproduce in greater number than needed solely to replace the individuals will likely have better chances of having offspring surviving into the future.

Life is not a sure thing but death is. No one survives forever.
3. Variation happens.
Whether reproduction is asexual or sexual, variation inevitably exists in the population.


The offspring from reproduction have a constitution and appearance that is similar but not identical in every way to the parent.

Variation in asexual organisms that produce clones and sexual organisms can be the result of copy error, point mutations, environmental mutagens and more.

In sexual creatures, the offspring are a new recombination of genes from both parents. Variation in genetic composition and/or phenotype can occur by factors in the environment before (developmental), before/after birth of the offspring (epigenetics) and of course during (lifetime conditions).

Variation exists in the offspring, they are not exact copies.
4. Stuff gets handed down.
Offspring get their genes and the recombined traits of those genes from their parents.

Whether sexual or asexual, parents contribute to the genes of their progeny. In sexual reproduction, a mix or recombination of the parental genes are present in the descendants and are passed then passed on, recombined, passed on. Genes that make certain traits possible can and may be there in the offspring in a dominant state that is always expressed or a recessive state where expression depends being diploid with another recessive allele. Mind you, they will in some measure be present in the offspring of their relatives and in the population. A type of fitness that is known as inclusive fitness.

Offspring traits and variations are inherited from the parent(s).
5. Good stuff happens. 
Some traits will be adaptive and enhance the individual's ability to survive and reproduce.

All things being even, sooner or later, a small advantage improves the individual's chances of contributing to posterity. Some of the variations will have a quality that assists in the struggle of life, others assist in covert ways. Nonetheless if there is any opportunity which gives even the most minute advantage in reproduction of the individual's traits, that's an "evolutionary" good thing.

Inherited variation will sometimes be better suited to ecology.
Suggested 
Further Reading:




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