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Tuesday, November 30, 2010

"Geo" Things - Everything We Don't Know (Chapters 9, 10, 11, and 12)

Hello, again! Just thought I'd note that we're over halfway through the book! Time flies when you're summarizing!

The next few chapters are about GEOlogical records and GEOgraphical distribution. It's also about all the things we are ignorant of - such as all the fossils we have missing and all of the details of the past (migration, ice ages, etc) that we fail to consider.

Darwin spends two whole chapters discussing fossils. In chapter 9 "On the Imperfection of the Geological Record," he asserts in many more words than necessary that even though we do not see intermediate species in fossils, the theory of Natural Selection still stands. We just have a really lame fossil record. I find this point well emphasized, since it is included in the name of the chapter, a name of a section of the chapter (On the poorness of our Paleontological collections), and throughout the chapter itself. I'm convinced!

Chapter 10 beings,

"Let us now see whether the several facts and rules relating to the geological succession of organic beings, better accord with the common view of the immutability of species, or with that of their slow and gradual modification, through descent and natural selection" (312).

In other words - Let's see if fossils prove my point or special creation?

Since this is Darwin's book, I think it would be safe to assume that the following chapter will prove his point.

One of the most interesting points, that is somewhat obvious but that I never stopped to think about is that once a species is gone it never comes back. "When a species has once disappeared from the face of the earth, we have reason to believe that the same identical form never reappears" (313). I've always known that once an species is extinct it is gone forever. But I think of it differently when considering Natural Selection. Closely related species still exist, so now I would think that variations could "bring" back the same species. But extinction is just as final as it always was.

To further support his theory, Darwin mentions that extinct species are always less related to extant (living) species the longer ago they went extinct. He then suggests, "Let us see how far these several facts and inferences accord with the theory of descent with modification" (331). Oh, Darwin. You just love setting yourself up for a win, don't you? According to descent with modification, each generation consists of small changes that accumulate to make big changes. The longer the time, the more the change. So, yes, this fact does support Darwin's theory. Surprise!

Just an interesting fact, which you should not remember on your next Biology exam, because part of it was discredited:

Darwin mentions that, according to Agassiz, "ancient animals resemble to a certain extent the embryos of recent animals of the same classes" (338). In other words, embryos look more similar to their ancestors than the full grown animal does. The reason I like this theory is because of one of the names for it (this is the discredited part): Ontogeny recapitulates phylogeny. Say that three times fast. Or just use it in any argument and your opponent will assume you know what you're talking about. It means that the developments from zygote to birth replicate the evolution of the species. This is not true. But it is interesting!

Now, chapter 11 "Geographical Distribution" and chapter 12 "Geographical Distribution - continued"

Essentially, Darwin says that all member of a species originated from one ancestor. But to prove this, he must explain how members of the same species ended up in different places...otherwise they would each have been created in the new geographical spot, which would kind of mess up Darwin's theory. Darwin's answer is basically that the make up of the earth wasn't always the way it is now...some places were more reachable than they seem (islands were closer together, etc) and that the one species did, in fact, migrate from one place. The opposite is also true - the places that are truly harder to reach have less common species with places around the world, because species could not migrate to them. He also shows, through many experiments, that plants can do the same by being transported via water (water itself, and fish) and air (birds).

Here is a true eccentricity of Darwin. Not even a mini one. A real one. But it happens to not be explained in the book, so just take my word for it. Darwin and his son would do experiments on dead birds...putting seeds inside them and having the dead bird float inside a bowl or their tub for a certain length of time to see if a seed would survive in the water in a dead bird. That's not my idea of a fun experiment, but, you know, to each his own.

Darwin's last sentence of Chapter 11 is the following:

"The various beings thus left stranded may be compared with savage races of man, driven up and surviving in the mountain-fastnesses of almost every land, which serve as a record, full of interest to us, of the former inhabitants of the surrounding lowlands" (382).

What I want to point out here, is one of the few mentions of the human race. Here, Darwin equates "savage" men, or uncivilized ones, I would assume, to animals that migrate in order to survive and then remain separate from other species. Now, I'm a firm opposer of Social Darwinism, and I don't believe that Darwin intended his theory to be used as justification for subjugating other humans. However, he does mention the "savage man" a couple of times, and I always make note of it, just because it makes a clear statement about how people of his time thought. Darwin clearly was a man who thought out of the box, and yet he still compares "savage" humans to other species, as if they were not even human at all.

Chapter 11 and Chapter 12 are definitely connected, and I've somewhat blended my summary of the two together. Just FYI, chapter 12 is more focused on islands, which makes it special and different from chapter 11!!

I'm a fan of the gardener metaphor in chapter 12:

"Nature, like a careful gardener, thus takes her seeds from a bed of a particular nature, and drops them in another equally well fitted for them" (388).

In other words, plants and animals can survive in more than one area. Short, but sweet, right? It's just a pretty sentence.

Another one liner is a sarcastic one that Darwin asks when discussing how bats seem to be one of the only mammals that occur on islands:

"Why, it may be asked, has the supposed creative force produced bats and no other mammals on remote islands?" (394).

The answer is: It (the creative force) hasn't. (Detailed answer: bats are one of the only mammals that can transport itself across the ocean, and therefore migrate to the islands. They were not created there specially.)

And just in case none of this made sense to you, as per usual, Darwin summarizes both chapter 11 and 12 at the end of this chapter. (But don't tell anyone that I told you.)

Until next time!

Monday, November 29, 2010

Why you should not believe my theory (Chapters 6, 7, and 8)

These three chapters detail all of the reasons that you might think Darwin's theory does not make sense. Luckily, he does not elaborate on them just to confuse you, he explains why you can still believe his theory. Although he does mention more than once that "if it could be proved that any part of the structure of any one species had been formed for the exclusive good of another species" (201), or for no apparent reason, or detrimentally, or just for funsies, "it would annihilate my theory" (201). Darwin either is good at looking ahead at other people's arguments against him, or he just loves killing his own theory. Before going into specifics, I will briefly explain the difficulties. If you do not care for that part, skim down to the "Wondrous Things!" section.

The difficulties are:

Chapter 6 - Difficulties on Theory
1. We don't see any transitional varieties (now or in fossils)! Answer: Fossil record is too imperfect to depend on, and transitional varieties do not exist anymore, because they were replaced by the new varieties! That is the point of Natural Selection!
2. How can complex and "perfect" organs, such as the eye, come about if there is no final purpose to Natural Selection? Answer: Each slight modification was beneficial for the organism, not just the final result. Over a long period of time, it evolved into this specific complex organ.
3. Why do useless organs exist if each organ varies to benefit the organism? Answer: Once upon a time, the "useless" organ was important, or even vital. Natural Selection cannot "delete" an organ just because it is not as useful anymore. These things take time.

Chapter 7 - Instinct.
Instinct causes a problem for Natural Selection because of a) lack of transitional forms, b) its complexity, c) isn't instinct learned? it's not inherited!, d) what about altruism (acts that do not benefit the organism itself)?
Problems a and b we answered in the last chapter. c) Instinct is, in fact, inherited. It could not possibly be learned over and over. Nor could it be learned by one generation and then inherited by the following generations. Just like other variations, instinctual habits accumulate over time. d) altruistic acts are not always altruistic. They could benefit kin (kin selection) or the group (group selection).

Chapter 8 - Hybridism.
The inability to inter-cross species is endowed by the Creator to prevent mixing of species, so that they should all remain identifiable.
Answer: Some species can cross and some hybrids (the offspring of the crosses) are fertile, whereas some organisms of the same species cannot cross or produce fertile offspring. These exceptions to the rule make it clear that a Creator did not specifically make this rule. Sterility is "incidental on other acquired differences" (245).

Okay!
On to....

"Wondrous Things!!"
Back to Chapter 7 and the ridiculous complexities in nature. Instead of discussing how they add or detract from Darwin's theory, I just want to point out these complexities so that we can think about them and appreciate them (if we're in the mood).

Slaves in Nature
Apparently, there are ant-slaves. The sterile female ants are raised to work for their community. In some cases, the males and fertile females do not work at all. In other cases, the "masters" collect food and materials for the nest. The ants we think of as common - the big, black ants - those are all infertile, female slave ants. The masters are red and about half the size of the slave ants. Maybe it's just me, but I think that is pretty insane. The slaves even carry the masters in their mouths when they migrate. The slaves raise the children and the masters capture other slaves. You have to wonder how closely related we might be to ants after all.

Bee Hives
I've always been fascinated by bees making hives, or bees doing dances to indicate pollen, and all of those crazy instincts. But I had no idea how particular the cell-making of the hives was. The bee has to excrete the exact amount of wax that will create a cell wall the most efficiently. There is not wasting of wax - the walls are the perfect thickness. Even the perfect shape of the cell, the hexagon, allows sharing of cell walls and saves wax. They must be a green-friendly community. It is hard for me to learn about these complexities and attribute it all to instincts, and not intelligence. But that just shows the power of Nature and of Natural Selection - these were not just ingenious ideas that the bees came up with one day. The instincts developed over time because they were beneficial to the bees. You make a good point there, Darwin.


There are other things to be said about these chapters, such as the confusing differences between crosses (the parents), hybrids (offspring of two species), and mongrels (offspring of two varieties), the amazing-ness of the eye (light reflects and gets interpreted and there are lots of nerves and crazy scientific things) and the throat (the glottis closes so you don't choke while you're drinking!), and electric organs (like in eels), AND the mention of HUMANS ("I might have adduced for this same purpose the differences between the races of man, which are so strongly marked...some little light can apparently be thrown on the origin of these differences, chiefly through sexual selection" [199].), I think I'll just end with the "Wondrous Things!!" because they are so wondrous. Next time you see ants or bees or any other animal that you never stopped to appreciate before...think about it.

Sunday, November 28, 2010

Variation...again? The answers for the question we can't answer. (Chapter 5)

Chapter 5 "Laws of Variation" begins,

"I have hitherto sometimes spoken as if the variations...had been due to chance. This, of course, is a wholly incorrect expression" (131).

1. Yes, Darwin is discussing variations again.
2. Darwin gives possible explanations for why variations occur, and then goes on to say, "Not in one case out of a hundred can we pretend to assign any reason why this or that part differs" (167).

But, never mind that. Even if we cannot decide why each organism has varied the way it has, it comes in handy to know the possible causes of the variation. So, now that we have a working theory of Natural Selection, we are returning to the 'raw material' of variations and exploring its causes.

As for the content of the chapter, Darwin is pretty straight forward in this one. So I will point out the headings of the sections and explain what he means by them (except the two headings that are self-explanatory, as you will see):

--(beginning of the chapter - no heading)
The changes or disturbances in the parents' reproductive systems is the main cause for change in the offspring.
--Effects of Use and Disuse
Use of an attribute of an organism strengthens that attribute, and disuse of an attribute diminishes it. If an organism has no need for an organ or a limb, it may, over time, vary to have a diminished version of that organ or limb (or none at all).
--Acclimatisation
"The degree of adaptation of species to the climates under which they live is often overrated" (139). We often think of parts of a species being attributed to its climate, ie. polar bears' fur. But actually, the climate is only part of the equation, and polar bears have their specific kind of fur for many reasons that we cannot pinpoint.
--Correlation of Growth
Sometimes when one variation occurs, another occurs in the same animal that correlates to it. Especially as an embryo, where certain parts of the body are homologous, those parts might vary together.
--"A part developed in any species in an extraordinary degree or manner, in comparison with the same part in allied species, tends to be highly variable" (150).
Yes, that is a title. It means that if a species develops a part abnormally (compared to other similar species), that part is extremely variable. This would not apply to the wings of bats developing, for example, because other bats have wings as well (150).
--"Distinct species present analogous variations; and a variety of one species often assumes some of the characters of an allied species, or reverts to some of the characters of an early progenitor" (159).
Different species can vary in similar ways and can also revert back to characteristics of an ancestor.

The rest is examples and evidence. Important stuff, I know, but I could not possibly rewrite the whole book here. So, if you are interested in that part, check out Chapter 5 of The Origin.


Darwin ends the chapter on a strong note once again, driving home the fact that all of this does relate to and support his theory:
"...it is the steady accumulation, through natural selection, of such differences, when beneficial to the individual, that gives rise to all the more important modifications of structure, by which the innumerable beings on the face of this earth are enables to struggle with each other, and the best adapted to survive" (170).

Tune in next time for...The Difficulties! (cue ominous music)

Saturday, November 27, 2010

...Itttt's Natural Selection (part II) (end of 3, Chapter 4)

Ok, so the ridiculousness of that sentence on page 79 can be explained as follows:

In Victorian England, as Darwin wrote The Origin, the popular view of Nature was one of love, harmony, and beauty. And then Darwin writes about all of the competition and destruction that occurs in Nature. In order to keep his readers happy, he ends the chapter (remember the importance and the first and last sentences of the chapters?) on a happy, albeit cheesy, note.

The last chapter for today is Chapter 4 "Natural Selection". His chapter titles are almost as creative as my post titles, right?

What I found interesting about this chapter was that it is really the crux of Darwin's theory, and yet it receives no extra attention, it has no asterisk next to the title saying *THIS IS IMPORTANT. It just falls straight in with the rest of the chapters. Of course, Darwin spent the last three chapters explaining domestic variation and natural variation and the struggle for existence, all so that he could explain natural selection. So it seems that chapter 4 is a logical place to put it. And perhaps Darwin did not want to direct the attention of his critics straight to his most valuable chapter. I just think it could have used a little more pomp and circumstance.

Chapter 4 is one of the longest in the books, and so you might expect that I would have a lot of commentary on it. However, most of the chapter contains examples of natural selection, numbers, calculations, and a chart. These scientific and mathematical sections were too much for my literary mind to comprehend, so I actually have less to say than the chapter might demand.

What I will comment on, however, is the metaphor at the end of the chapter. Darwin explains the lineage of organisms as if it was a tree. All limbs, branches, twigs, and buds of a tree are connected by the trunk. They are all related, some more than others, and they all compete with each other to survive (129). Darwin ends the chapter, returning to the beautiful images of Nature that he began in chapter 3:

"As buds give rise by growth to fresh buds, and these, if vigorous, branch out and overtop on all sides many a feebler branch, so by generation I believe it has been with the great Tree of Life, which fills with its dead and broken branches the crust of the earth, and covers the surface with its ever branching and beautiful ramifications" (130).

It's a Variety! It's a Species! Itttt's Natural Selection! (Chapters 2 and 3)

Chapter 2 "Variation Under Nature" begins:

"Before applying this principles arrived at in the last chapter to organic beings in a state of nature, we must briefly discuss whether these latter are subject to any variation" (44).

Conclusion: They are.

In chapter 2, Darwin discusses the differences between variations and species, and gets essentially no where. To be fair, he does mention that varieties are known to be able to interbreed while species cannot (49), but there are always exceptions to the rule, blurring the line.

While Darwin uses the terms "variety" and "species", he also says, "The terms variety, in comparison with mere individual differences, is also applied arbitrarily, and for mere convenience sake" (52). I love this quote because it shows Darwin's ability to put himself in rank with other scientists and naturalists, while simultaneously insulting them. At the same time, this quote sums up his point that it is hard to distinguish varieties from species and the labels often get confused.

Chapter 3 "Struggle for Existence"

Darwin goes 'all-out' in this chapter. The chapter is full of descriptions of Nature and its power, and Darwin emphasizes it all with metaphors, pretty words, and cheesy sentences.

Page 61 - "We see beautiful adaptations everywhere and in every part of the organic world."

AND
"Natural Selection, as we shall hereafter see, is a power incessantly ready for action,and is as immeasurably superior to man's feeble efforts, as the works of Nature are to those of Art." (No offense to painters, sculptors, musicians, etc.)

But he is not always nice about Nature; sometimes its power is more ominous:

"We behold the face of nature bright with gladness, we often see superabundance of food...we forget how largely these songsters, or their eggs, or their nestlings, are destroyed by birds and beasts of prey" (62).

Or sometimes he is more literary and confusingly metaphorical:

"The face of Nature may be compared to a yielding surface, with ten thousand sharp wedges packed close together and driven inwards by incessant blows, sometimes one wedge being struck, and then another with a greater force" (67).

I've polled my family members and peers and the clearest interpretation of this metaphor that I've heard is that, in nature, when one "wedge" is hit, it always effects another "wedge". That is, everything is connected and all organisms impact each other. In the context of the chapter, in which Darwin elaborates on a few checks in nature (means by which organisms keep the population of other organisms down), this interpretation seemed fitting. Make of it what you will. And feel free to comment with additional interpretations!

I would have to say, however, that my all-time favorite sentence in On the Origin of Species occurs at the very end of this chapter. The last sentence! In fact, I like it so much, I think I will have to end this post immediately after quoting it, just for the sake of impact. Then, I'll immediately post another one explaining it (and more!):

"When we reflect on this struggle, we may console ourselves with the full belief, that the war of nature is not incessant, that no fear is felt, that death is generally prompt, and that the vigorous, the healthy, and the happy survive and multiply" (79).

Friday, November 26, 2010

Pompous Prose (Introduction, Chapter 1)

"When on board the H.M.S. 'Beagle,' as naturalist, I was much struck with certain facts in the distribution of the inhabitants of South America, and in the geological relations of the present to the past inhabitants of that continent" (Darwin, 1).

The first sentence of Darwin's introduction immediately sets Darwin up as a credible source, as a naturalist, similar to other scientists of the time, and as someone who researched 'in the field' in South America. On the first page, he continues to mention himself 17 times ("I", "me", and "my" included) and tries to 'one-up' his arch nemesis, Alfred Russel Wallace. Okay, so maybe they are not arch enemies, but they did think of the same theory of natural selection, at the same time; Darwin spent 20 years thinking about it, Wallace spent only a few. Anyhow, Darwin writes, "It occurred to me, in 1837, that something might perhaps be made out on this question" (1). Certainly, Darwin mentioned the year of the conception of his theory to tell the public that he did, indeed, discover the theory before Wallace. I see it as the blessing and curse of scientific research: Many people are striving to discover the world and all of its intricacies, but they all compete with each other because once a discovery is made, it can never be discovered again.

Then, at the end of the introduction, Darwin confidently disregards the theory of special creation - that is, that each creature was intentionally created by God, not that the creatures came to be through natural laws. He writes, "the view which most naturalists entertain, and which I formerly entertained - namely, that each species has been independently created - is erroneous" (6). I love the word erroneous. Perhaps, in Darwin's time nothing was special about the word, but I see it as a complete 'shut-down' of the recipient of the label. Hence, it is completely, utterly, entirely false and untrue that each species was created separately. So says Darwin.

On to Chapter 1 - Variation Under Domestication! In Chapter 1, Darwin makes an effective comparison between domestic variation and natural variation. In order for Darwin's theory to work, variations must naturally occur and then certain ones must be naturally selected, causing evolution of species. Here, Darwin argues that people witness variation among their domestic animals, so why can't variations occur in nature? Sure, domestic animals are actively bred, and there is a "selector" deciding which variations stay and which go, but Darwin is always a proponent of the power of nature. Humans are nothing compared to its forces. (That's a slight paraphrase.)

My favorite part of Chapter 1 is the pigeons! Yes, Darwin goes on and on about pigeons. He has good reason though - everybody loves pigeons. In Victorian England, pigeons were bred by commoners. The idea of breeding pigeons was a familiar one and a hobby to many. Darwin also appeals to the lower class, and thereby a broad audience, by mentioning the significance of pigeons. Now all of the pigeon breeders feel important and start listening to Darwin's ideas. At least, that's one way to look at it.

Darwin is kind to all fellow men as he writes, but he is not afraid to put down the classic Greek philosophers. Part of Aristotle's view on nature was that every creation has a final cause, or a purpose. Darwin, however, disagrees. On page 37, still comparing natural selection to domestic selection, Darwin writes that gardeners never plan for the final plant they end up with. Along the way, they choose variations that they like, and continually improve the plant. Natural selection works the same way. The creation does not have a final purpose, as the great Aristotle might say, rather, according to Darwin, each variation is selected by nature because it is beneficial to the organism (not because the organism is striving for a goal).

Darwin ends Chapter 1 by asserting the power of nature and the power of his theory (pompous prose? I think so):

"Over all these causes of Change I am convinced that the accumulative action of Selection, whether applies methodically and more quickly, or unconsciously and more slowly, but more efficiently, is by far the predominant Power" (43).

Thursday, November 25, 2010

The Mechanics of the Blog

Dear Readers,

In this blog, I will be going through the first edition of On the Origin of Species by Charles Darwin and pointing out "the eccentricities of Darwin" through his writing. As I read The Origin I was surprisingly amused by the way Darwin would explain himself. He is blunt and subtle, serious and sarcastic, he is slightly pompous and yet he relates to the "commoners". He is modest and somewhat unsure, and yet, he never fails to point out the infallibility of his theory.

Darwin deliberately sets up the first and last sentences of his chapters, and because of this, I will begin and end many posts discussing these. I will guide you through The Origin so that you may use this blog as both a source of amusement and practicality, so that if you should read the The Origin you will know what to look for in the text.

I will discuss about two chapters per post, and within a week, we will have gone through the book in its entirety. Hope you enjoy!

Gabriella