How Does Use and Disuse Influence Evolution in Darwin's Theory?

[nautica]

THE ORIGIN OF SPECIES
By Charles Darwin

See attached

Nautica

 

[selfAdjoint]

Very nice and ingeneous review.

 

[nautica]

Thanks

 

[Mentat]

Very well done, nautica...I really appreciated (among many other things) the reference to the only time that Darwin even used the term "evolve", though it has become the name of the theory itself.

One question though, I may have skimmed a little, so I don't know for sure: was Lamarkian evolution mentioned? Was this dealt with in "On the Origin of Species"?

 

[nautica]

Chapter 4 - Natural Selction, or Survival of the Fittest.


"But it may be objected that if all organic beings thus tend to rise in the scale, how is it that throughout the world a multitude of the lowest forms still exist; and how is it that in each great class some forms are far more highly developed than others? Why have not the more highly developed forms everywhere supplanted and exterminated the lower? Lamarck, who believed in an innate and inevitable tendency towards perfection in all organic beings, seems to have felt this difficulty so strongly, that he was led to suppose that new and simple forms are continually being produced by spontaneous generation. Science has not as yet proved the truth of this belief, whatever the future may reveal. On our theory the continued existence of lowly organisms offers no difficulty; for natural selection, or the survival of the fittest, does not necessarily include progressive development- it only takes advantage of such variations as arise and are beneficial to each creature under its complex relations of life."

Chapter 8 - Instinct

"For peculiar habits confined to the workers or sterile females, however long they might be followed, could not possibly affect the males and fertile females, which alone leave descendants. I am surprised that no one has hitherto advanced this demonstrative case of neuter insects, against the well-known doctrine of inherited habit, as advanced by Lamarck."

Chapter 14 - Mutual Affinities

"Analogical Resemblances.- We can understand, on the above views, the very important distinction between real affinities and analogical or adaptive resemblances. Lamarck first called attention to this subject, and he has been ably followed by Macleay and others. The resemblance in the shape of the body and in the fin-like anterior limbs between dugongs and whales, and between these two orders of mammals and fishes, are analogical."


These were the only times I found his ideas mentioned.

Nautica

 

[nautica]

“The evidence that accidental mutilations can be inherited is at present not decisive, but the remarkable cases observed by Brown-Sequard in guinea-pigs, of the inherited effects of operations, should make us cautious in denying this tendency.”

An interesting note that I have recently found out. This statement was not included in the first edition of Darwins book in 1859, but did appear in the later editions and most importantly his 6th edition, which is the one in circulation.

After researching, I found where Brown-Sequard visited and gave lectures to the Royal Society, which Darwin was a member, in 1859. It appears that Mr. Darwin was impressed enough to include this in his final edition.

Nautica

 

[Nec]

Good job, Boy!

 

[nautica]

Back to the Larmarckian question.

Although those were the only specific times in which Mr. Darwin mentioned Lamarck, Mr. Darwin does attribute, at least in part, use and disuse to variations within an organism. But he does say that the accumulations of the variations is due to "Natural Selection".

He also goes on to say that use and disuse is only a very small cause of variation and most variation is due to either spontaneous changes or through latent characters. The later, of which he felt was the most important, are characters or traits that were once useful in an organism, then went dormant and for some reason have resurfaced.

And, of course, we now know that it is the spontaneous changes (Mutations) that allow natural selection to work.

Nautica