So new species can't arrise suddenly...

Correct. Most new DNA is 'junk' DNA, an artifact of the imperfect replication process that most DNA based life exhibits.

It is most often due to an extra copy of a gene due to transcription error, or even an extra base pair created during strand slippage. Since most DNA is 'junk' DNA (i.e. doesn't code for anything) it usually doesn't do anything.

However, once in every N copies, the new gene DOES do something - and a random mutation containing new genetic information has been created.

Yes, and it happens all the time, even in human DNA.

Yes, for two reasons:

1) Most DNA is junk DNA. It doesn't do anything.

2) Once the error occurs, there are at least two mechanism that try to fix it. The first is proofreading, a process where the new strand is compared to the old strand, and if the incorrect amino acid has been paired with the template, it is replaced with the correct one. The second is mismatch repair, where deformed strands (i.e. ones with incorrect or too many amino acids in the new strand) are repaired. These mechanisms are themselves, of course, imperfect as well - which is why the genome sometimes grows and sometimes shrinks.

It is neither unimportant nor fragile. 99.99% of the time it can still operate with replication errors - which is very good news for us.

 

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James gave me a warning for 'trolling and meaningless content' and a ban threat on this post. Please note: "IMPO" (In My Professional/Philosophical Opinion) caveat.

 

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Arioch . . . Please Google: Casimir Effect . . . apparently NOT pseudoscience . . . then research its interactive effects on (~ similar scale) organic structures (e.g., neurons, etc.) NOTE: James R . . . NOT trolling, simply responding to Arioch's query.

 

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Conditions that permit rapid evolution of new species (no fertile offsprings when cross breed):
“From http://www.sciforums.com/showpost.php?p=2687668&postcount=1016 :

(1) Isolated gene pool, so new benefitial gene for that enviroment will not be too quickly lost among a wider population
(2) Very small gene pool so new beneficial gene can quickly spread through out the small gene pool.
(3) No Predators to eat the bearer of the new beneficial gene before it can be spread into later generations.
(4) Harsh conditions so that even a slight beneficial gene may make a difference in survival. For example creatures that only can digest bananas might have a genetic change that allowed them to digest grass, but if there are lots of bananas available and that is what the bearer of the grass digestion gene learned to eat, that gene, although potentially beneficial, will not offer much survival advantage, until the massive banana blight hits and 90% of the gene pool starves to death. I.e.
(5)Very harsh environment conditions make even small genetic advantage very big survival advantage. - Get it selected for.
(6) Harsh condition lasting for long periods, no just a passing drought etc. but for tens of thousands of generations with a significant fraction of the gene pool starving to death every generation due to over breeding.
(7) Being trapped in a tiny areas with no means of moving to where conditions are less harsh.

If all seven are strongly satisfied, then the rate of evolution can be speeded up by a factor of 100 (not a million years, but species evoluting in 10,000 years.)

It just so happened that from the end of the last ice age, about 8,000 years ago, all seven were very strongly in effect for the full 8,000 years and a new species did evolve, confirming these seven predictions of evolution theory. That species, called the preá, evolved from the guinea pig species that lives still unchanged on a much larger island only 8 Km away by boat. Not only do the preá, have quite a different appearance, size and facial features, (very tiny and flat –quite human like with no snout) etc. but the preá, cannot mate and produce fertile off springs with the guinea pig species they evolved from. – I.e. the preá, is a new species.

See photo of preá and read more on the preá here: http://www.sciforums.com/showpost.php?p=2682823&postcount=949
Note especially how the eyes have moved close together for better depth protection and the hair whorls on sides of the head where they once were.
Side looking eyes are the rule for all animals that are food for others, but this 360 degree vision does give them very poor depth perception. As there were no predator animals on the tiny island and many advantages to good depth perception the eyes of the preá became very close together and forward looking. In fact the preá are the only animals on the island as that term is normally used but there may be some earth worms or bugs etc.

While new bacterial organism can evolve in less than 24 hours, I think the no other mammal has become a new species as rapidly as the preá did.

PS to wellwisher Making all these changes that the preá did so rapidly no doubt increased entropy, but it is survial selection advantages that are selected for NOT lower entropy. Entropy plays ZERO role in evolution. Get off that stupid horse.

 

I know that the Casimir Effect is, I'm asking what "casimir effects", which is the phrase you used, are. I also know that the Casimir Effect takes place on the quantum level, below even the sub-atomic level, so that once you get something the size of a strand of DNA the various quantum effects have effectively cancelled each other out.

 

Arioch: Have a look at the 'scale' on which the Casimir Effect (CE, or 'effects') operates . . . generally (from our current experimental data) in the sub-micron (nanometer) to ca. 25 micron scale. THE Casimir Effect has been experimentally demonstrated and verified by Casimir and others (e.g., Lamoreaux) using mechanical nanometer-sized experimental devices. There is also verification that CE interacts with constructed nano-machines - and observable effects may be expected in development of the 'quantum computer'. There is now only preliminary research into verifying the Casimir Effect interactions with other (e.g., organic) media. Little (if anything) has been verified for CE, and possibly similar (or related) quantum mechanisms, regarding organic interactions (or moderating effects) at the micron and sub-micron molecular level. My intimation is that such quantum-effect interactions very likely DO occur and that such interactions may influence the behavior of molecular and organic processes. Don't ask me for proofs . . . I have none other than examining others' work . . . scan (Google) the literature . . .(e.g., have a look at "Quantum Consciousness"). I'll leave you with something I posted on another Thread: "To understand the infinitely large universe, one must comprehend the infinitesimaly small universe"

 

This isn't quite macroevolution, as what's happening is variance in a population here...but the fact that such a large complex animal can exhibit phenotypic change this fast I find interesting:
http://www2.chinadaily.com.cn/english/doc/2005-07/16/content_460623.htm
Phenotypic change in response to human predation.

 

First how do I get to their home page english version? I read http://usa.chinadaily.com.cn/ almost every day and would like the link to their home page - my attempts to find it only produced chinese.

your link states:
"It is not the result of natural evolution. Rather, it is a reluctant choice made in the face of a gun."

Which seems to imply that man is some how not part of nature. Man has been by far the most rapid cause of gene pool changes for at least 10,000 years, both in plants and animals. Also strange in their sentence is the idea that choice is part of evolutionary selection.

I also want to note that NOT killing has also made large phenotype change. I Don´t remember details well but in China (or Japan?), there was a famous warrier / warloard who had to cross a bay (of the sea). His boat capsized and with the weight of his armour, he drowned.

Crabs are often caught in the fishermen´s nets and most are kept for cooking, but some have ridges on the shell back and some of them reminded the fishermen of a face. In honor of the war loard, they are usually thrown back in the sea when removed from the net, instead of into the crab pot. This has been happening for several hundred years. Now some crabs have a very human like face on their back.

Of course not all the changes man has made in the biological gene pool have been extinction of species. Some have been modified to serves man´s desires. Like huge utters and milk production of cows, all sorts of varieties of dogs from the wolf, etc.

IMO this is all "natural selection" as man is part of nature. Darwinian survival of the more fit for the current enviromental changes, be those changes caused by man´s release of CO2, his desire for more productive chickens, or by ice ages, etc. makes no difference - it is "natural selection" at work. "Natural" really means "unavoidable" or "inevitable" and does not refer to the agent of the change - just that there is no choice - a stastically certainity at work coping with the changed enviroment when not all can survive.

 

He is part of nature, but what he makes is not natural. Twinkies are not natural food, for example.

Artificial selection, actually. Dogs are artificially bred for certain characteristic.

No, it doesn't. It means "part of the natural world." A wild forest would qualify; Manhattan would not.

 

There are roughly two ways, I think, to have observed macro evolution.

The most siginficative way is to infer close kinship between different species, say "A" and "B", from what we can safely assume to be evidences of biological kinship. It's usually like the sort of differences that happen within the species, only to a larger degree. Then, depending on your criterion for "macroevolution", you'll do that with how many species you think suffice to account for macroevolution. Somewhere between "A" and "G" or whatever. It's likely that the species between these two will have intermediate traits helping to understand how the differences between one another evolved. This can be further studied with fossil findinds and perhaps, more significatively, developmental experiments.

This is how the bulk of macroevolution has been observed, indirectly.

Direct observation will be more rare, in situations such as that of ring species, or some lab experiments on which perhaps they select for hybrid inviability/sterility or different patterns of sexual attraction in the case of animals. Or they may "stumble" with something that looks like that in nature (somewhat like ring species).

When this sort of thing happens, what it means is that, say, all the finches that hadn't genes for beaks of a given size range/color/whatever, have failed to produce offspring. Then the next generation would have only a "slice" (or "a slice less", depending of how much of the population went extinct) of the precedent beak size/color/whatever variation.

I don't think that such cases are that relevant to "macroevolution", only to natural selection, except when they may intersect in a very specific way such, all intermediate sized-beaks/colors dying, and the birds of the extremes of variation tending not to mate with the birds of the other extreme. Withot the intermediates forming a "reproductive bridge", they're different species by some criteria, and possible in the way of becoming different species, by more restrict criteria.

I guess that sometimes such an event could happen in a way where the "bridge" that disappears is making the "hybrid" offspring between "extremes" physiologically viable, rather than just behaviorally more likely. I don't know of any such case, but I guess that there may be examples on insects or "simpler organisms", more than with vertebrates or specifically mammals.



Something similar could happen anyway even with mammals/"advanced" organisms that's quite similar to it, I guess. If individuals that have had a chromosomal "fusion" aren't reproductively uncessful right away, disappearing from existence, they're essentially different biological species already. Hybridization is much more unlikely than reproduction with an organism with the same chromosomal arrangement.

Something like that eventually happened between our lineage and the lineage of the other hominids/apes. I think that the blog Pharyngula has a reasonable explanation of the issue:

http://scienceblogs.com/pharyngula/2006/09/luskins_ludicrous_genetics.php

Not that it's particularly good, I just don't quite recall of any other, and perhaps that's good by preemptively refuting some creationist claims.

 

Talk origins has a page on "observed instances of speciation", which may be taken as the same as "macroevolution" by some criteria:

http://www.talkorigins.org/faqs/faq-speciation.html

Regardless of the exact criteria, I think it's pertinent here.