RE: Refuting Darwin
That questions was dealt with in detail by Stebbins in his 1950 book.
Now he does not frame the question in the same way you do, but he investigates the sources of variation in plants and finds that there is A WHOLE LOT of unexpected variation out there. Evolutionary biologists at the time were really surprised at the amount of naturally occurring variation that Stebbens documents. This same type of work has been done for many other groups. The answer is always the same. There is a lot of variation in nature, and this variation is the raw stuff of evolution. So evolutionary biologists have approached your same question but from a different direction, and because they came at it from the angle of "well, just how much variation do we find out in nature?" they were able to provide an answer...
By the way, NO scientist takes the peppered moth example as proof. No scientist. We take it as a simple example that is used to explain the concept to 1st year students at an undergraduate level. The fact that there are problems with the example says a lot (!) more about textbook publishers than it does about evolution. There is a lot of bad things we could say about how science is taught in textbooks. I stopped using them in most of my classes. I got fed up with the way science is presented. Textbook publishers are out to make money. We should never forget that.
Prof of Biology in the U.S.
The modern version of The Theory of Evolution by Natural Selection, has itself evolved a bit since Darwin. (Modern scientists tend to avoid the phrase "survival of the fittest" due to the many misunderstandings it can lead to, and has.) Darwin's observations were amazing and spot on in so many ways, but it is true, he did not describe the actual mechanism of natural selection, only its effects, because Darwin did not have any knowledge of genetics. Gregor Mendel was working out the process of genetic inheritance in his garden of peas while Darwin was alive,
but the actual mechanism was not understood until an understanding of DNA came along in the 20th century. So, when you say:
"What most bothers me, however, is the assumption that the variations in form or color of the creatures involved occurred before their residence in favorable environments.'
It's a bit unfair. Darwin did not have tools to determine where the variations came from, but he made observations which showed that these variations did exist and were important. The modern theory of evolution by natural selection includes knowledge of genetic inheritance and knowledge of the biochemistry of DNA. Different species have varying amounts of variation between individuals present in their DNA.
Humans have a wide variation in many traits such as height and pigmentation. If a phenomenon came along that killed off people over a certain height, or people with too little melanin, humanity would survive, but for a period after that transition, the variation present in humans would be reduced. The key feature that leads to variation and the differentiation of species is that the replication of DNA is imperfect. There is always a chance of mutations happening during the reproduction process. The chance of a mutation is fairly low, otherwise species would just not be stable and would not persist. A large percentage of the mutations that do occur are detrimental and lead to failure of the organism (think miscarriages.) A small few of the mutations might actually be an advantage to the individual inheriting them, such as a slight change in beak shape that is better suited to the locally available food sources. These mutations will persist in the species. Much of the rest of the variation due to mutation is made up of unimportant changes. These can persist in the population as "genetic drift" where slight variations gradually accumulate in a species which are neither beneficial nor detrimental in the given environment. But if there is a shift in the environment of some sort, some of these pre-existing variations may actually become useful in the new environment. So, the source of the variations which lead to natural selection are either new mutations which by chance provide an advantage, or pre-existing but accidentally advantageous variations which are present due to the accumulation of variation from genetic drift over time.
For those British moths, the change in tree bark coloration happened fairly quickly in evolutionary terms. Insect generations are fairly short, so it would be possible for new mutated variations to build up relatively quickly, so it could have been some combination of pre-existing variation and new mutations which led to the coloration changes. For animals with longer generational cycles, the variations would need to be already present for adaptation to a quickly changing environment, but new mutations could be at play over the course of much slower environmental changes.
I hope that helps clarify,
Thanks for this good piece!!!
This doggerel of mine below is shorter:
While looking out upon my feeders,
The gathering there of feathered eaters,
Some words that Charlie Darwin spread,
Keep knocking hard within my head.
Could proof of natural selection,
Evade my honest mind’s detection?
Jays all blue and cardinals red,
Grackles black with bronzy head,
Finches’ golden sun-like dazzle!
Biologists! Behold this puzzle!
“Why sport such wings all drunk with color?”
Survival says, “You should be duller.”
But Goethe said it loud and clear,
What birds chirp forthright to our ear.
“Midst dark and light, the rainbow lies.
We flaunt our hues just for your eyes.
Camouflage is for the timid.
The Creator dares beyond all limit.”
I will see his paintings new again because of your post! The heart hears what the painter means when the poet acts as docent.….
Me imagino a Monet caminando por París, cruzándose con Lisel, mirándose ambos y sosteniendo esa mirada por unos eternos segundos.
thank you. One sentence was especially remarkable: "Steiner said that our higher being (the higher I) is in all that we meet outside and least within ourselves."
Cheers, Norbert Hanny
Thanks for making us aware of this important book!
7 Books, 4, 244 pages at least please. And then about 8 really well made films, preferably directed by Julie Taymor. Let me know when Mr Fox has completed, where I can purchase the hardbacks and see the first film. Thanks and Best wishes,
RE: If You Knew
Thank you. A moving poem which lonely people understand…
brilliant. I love it. More please
I just wanted to point to this resource as I believe the quality of translation is excellent and it is done for the love of it. There are free downloads in about 5 different formats:
I find receiving too many emails with single articles is not very helpful. I will try and log on to the SCR website every now and then to check for new editions as you suggest.
Thanks for your interesting work.
Thank you, and keep them coming. Did you notice your typo? " Mysery Centre" indeed. I don't read everything every time bcos of other pressures for a while, but fully intend to do so when life stops taking me by the ankles and swinging me around. I look forward to your presentations with great pleasure. Regards, Hilary. In Boston, Lincolnshire.
Glad you're sending out the 2-month compilation in addition to the weekly/bi-weekly installments.