Evolution in action

[MortenS]

MortenS: Do you have any information about flies bred on space stations?

 

I know they have brought Drosophila up in space on various occasions, but I have not looked for any results until now.

 

From the preliminary results I found accessible to me (a paper from 1968), it seems that the incidence of chromosome breakage and bridge formation between chromosomes where significantly higher in orbit than on ground, in flies that was irradiated both and in flies not irradiated.

 

Here is the article: http://www.pubmedcentral.gov/picrender.fcgi?tool=pmcentrez&blobtype=pdf&artid=225054

 

I also found some abstracts from various other experiments, but I do not have access to the journals.

 

Measuring Drosophila (fruit fly) activity during microgravity exposure.

Some results of the effect of space flight factors on Drosophila melanogaster.

The effects of microgravity on the character of progeny of Drosophila melanogaster.

 

Towards the establishment of a permanent colony of Drosophila in the International Space Station: hardware tests and adaptation of techniques.

 

Drosophila melanogaster and the future of 'evo-devo' biology in space. Challenges and problems in the path of an eventual colonization project outside the earth.

 

There are several other articles and reviews about this topic.

 

Search Pubmed with keywords such as diptera and microgravity, diptera space station, or diptera weightlessness and follow related articles links as you find interesting topics.

[joel]

>>Evolution has favored intelligence

 

??

 

What about all the bacteria, that have been breeding with 20 minute generation times for the past 3.5 billion years, and are the largest fraction of the earth's biomass? Are they geniuses?

 

Otherwise, I agree with your thought-provoking post. We're ready to let 'er rip when it comes to lateral transfer of genetic material.

[MortenS]

Morten,

That was a very nice little essay you posted of evolution being observed in the wild. I wonder if you'd mind me refering to it in a similar debate on another forum?

 

Be my guest!

[InfiniteNow]

>>Evolution has favored intelligence

 

??

 

What about all the bacteria, that have been breeding with 20 minute generation times for the past 3.5 billion years, and are the largest fraction of the earth's biomass? Are they geniuses?

 

Ah... perhaps it would be wise to reach a common understanding of "what is intelligence?" However, be cautious, intelligence does not at all necessitate genius.

 

 

Otherwise, I agree with your thought-provoking post. We're ready to let 'er rip when it comes to lateral transfer of genetic material.

Well thanks. :Waldo: I do what I can...

[ughaibu]

MortenS: Thanks.

[questor]

Morten, some interesting questions to me are:

1. why do we conclude that ape and man have a common ancestor, when no examples have been found? is it not possible these two species arose independently? if they did have a common ancestor, why has the ape not become more sophisticated, since his environment has been similar to man's?

and the time span has been the same?

2. since the genetic makeup of ape and man are so similar, why can't

they mate?

3. there have been many varieties of apelike creatures arising from the ape lineage ( chimps, lemurs, baboons), but only man arose from the human

lineage. why so?

4. if we can agree that Cro Magnon is '' modern man'', and made his appearance around 100,000 years ago, where is the fossil evidence of his progenitors? how did he so suddenly burst upon the scene?

 

''Summary

In a previous article101 I demonstrated the lack of suitable primitive ancestors for the australopithecines, for 'habilis' and for Homo erectus. In this paper I hope to have shown that the erectus-archaic-Neanderthal-modern man 'chain' is non-evolutionary; that is, that all these forms are simply varieties of human beings (see Figure 8).102 The question of time is irrelevant - it makes no difference whether the time involved is millions of years or only a few thousand. The morphological distinctions are very much insufficient to warrant placing these forms in separate categories which only serves the purpose of evolution - a theory to which so many scientists are committed as dogma. Once evolution is accepted as dogma, all evidence is interpreted in a subjective, rather than objective, manner. Creationists will continue to expose the weaknesses in the theory and to encourage further research and study into the origins of man. It is not simply a matter of blind adherence to religion; the evidence is available to all who honestly wish to study and evaluate it.

 

 

Figure 8. Skull outline of a 'progressive' Neanderthal. Authorities find it paradoxical that the more 'primitive' or classic forms appear in the fossil record before the more modern, 'progressive' types such as above.

 

The actual facts of the fossil record, that is the fossil materials themselves as against evolutionary interpretations of these materials, show indisputably that contrary to expectation the 'earliest' erectus skeleton (WT 15000 or the Turkana 'Boy') proves by its very existence that this human being was large like modern humans, and not small and ape-like. On the other hand fossil OH 62 proves that 'habilis', far from being Homo-like, was small and ape-like - these cases were the very opposite of what evolution theory predicted and expected.103 Even though the brain size of WT 15000 was smaller than most modern humans, it was still larger than quite a few people living today.''

 

LINK..http://www.answersingenesis.org/tj/v8/i1/erectus.asp

[InfiniteNow]

Sometimes it's like a blind man begging to be shown the light. No matter how brightly it shines at him, he still doesn't see it... and he keeps asking to be shown.

[Queso]

nice analogy, man.

[InfiniteNow]

nice analogy, man.

Thanks.

 

 

:hihi:

[MortenS]

Morten, some interesting questions to me are:

1. why do we conclude that ape and man have a common ancestor, when no examples have been found? is it not possible these two species arose independently? if they did have a common ancestor, why has the ape not become more sophisticated, since his environment has been similar to man's?

and the time span has been the same?

2. since the genetic makeup of ape and man are so similar, why can't

they mate?

3. there have been many varieties of apelike creatures arising from the ape lineage ( chimps, lemurs, baboons), but only man arose from the human

lineage. why so?

4. if we can agree that Cro Magnon is '' modern man'', and made his appearance around 100,000 years ago, where is the fossil evidence of his progenitors? how did he so suddenly burst upon the scene?

 

Let me see if I can try to answer your questions, questor

 

Point 1: Evidence for common ancestry between Homo sapiens and Pan sp. when there is lack of fossil evidence.

 

The main problem with fossils is that very few organisms fossilize. In addition, particular environments are not particulary suitable for the fossilization process, particulary not soil where bone tend to be broken down quickly, as it does in forests. Chimpanzees rarely travel out of forests to find themselves in environments more suitable to fossilization. So, the odds are stacked against finding fossils of chimpanzees.

 

In fact, the very first fossil of a chimpanzee got reported just last year, and it was about 540000 years old.

 

So, while there are thousands of fossils from hominids, there are just one fossil finding of chimpanzee, in form of chimpanzee teeth.

 

To prove the common ancestry of humans and chimps without fossil evidence, we have to look elsewhere.

 

Luckily, we have lots of other evidence for common ancestry, between human and chimpanzees (I will be happy to expand on any of these points if you need any details)

 

* karyotypes of chromosomes shows that the chimpanzee chromosome number 2p and 2q fused to form human chromosome number 2

* at least 7 retroviral inserts of the same viral DNA sequence in the same chromosome at the same locus in both humans and chimpanzees.

* Shared pseudogenes between humans and chimps. Pseudogenes are copies of functional genes, that have received a mutation that makes them non-coding. Humans and chimpanzees share several pseudogenes that are completely identical. Gene duplication is a rare event, so finding the same pseudogene with the same mutations in two species strongly support common ancestry.

* transposons: finding the same transposon in the same chromosomal location in two different species, strongly indicate a common ancestry, since transposons insert themselves randomly, and can only be transferred via inheritance.

 

Point 2

It is about 5 million years since the human lineage and the chimpanzee lineage split apart. In speciation processes it is common that hybrids eventually get reduced viability. The reduced viability of hybrids leads to natural selection favoring couples that are not producing hybrids. They can evolve behavioral, mechanic, and even chemical barriers to reproducing with each other.

 

As for humans and chimps, I have no idea whether they are capable of getting offspring together or not. Based on their time since divergence, I would guess that they are incapable to form reproductive offspring.

 

 

While there are rumours about such experiments being done in the past, it is difficult to get such results verified because of the obvious ethical minefields you step into if you want to 1. do this kind of research and 2. publish the results.

 

Point 3.

 

Actually, several lineages existed in the hominid lineage, and at times there were several hominid species coexisting. Unfortunately, every lineage but Homo sapiens sapiens died out. Homo neanderthalensis died out about 30000 years ago, and coexisted with Homo sapiens sapiens for about 100000 years at least. For 2 million years ago, Homo rudolfensis, Homo habilis and Australopithecus africanus coexisted on earth.

 

 

Point 4:

 

Incomplete fossil record perhaps?

 

Remember that fossils only will tell us at what times something was present on earth. Presence of a fossil in a strata is solid evidence for the existence of the organism in that period, but lack of a fossil in a strata is not necessarily solid evidence against the existence of it.

 

As for possible ancestors to Cro Magnon, what about Homo heidelbergensis or Homo erectus?

[questor]

Morten, it is good to converse with you. i am not an anthropologist or geneticist, although i worked in the medical field for 40 years. i think you have

good points here, but i will think you will agree that there are still areas of disagreement in the history of modern man's emergence. a few more questions:

1. how do you answer the Cambian question?

 

“There is another and allied difficulty, which is much more serious. I allude to the manner in which species belonging to several of the main divisions of the animal kingdom suddenly appear in the lowest known fossiliferous rocks.” (Darwin, The Origin of Species, p. 348),

 

“The abrupt manner in which whole groups of species suddenly appear in certain formations, has been urged by several palaeontologists—for instance, by Agassiz, Pictet, and Sedgwick—as a fatal objection to the belief in the transmutation of species. If numerous species, belonging to the same genera or families, have really started into life at once, the fact would be fatal to the theory of evolution through natural selection.” (Ibid., p. 344),

 

“To the question why we do not find rich fossiliferous deposits belonging to these assumed earliest periods prior to the Cambrian system, I can give no satisfactory answer.” (Ibid., p. 350),

 

“The case at present must remain inexplicable, and may be truly urged as a valid argument against the views here entertained.” (Ibid., p. 351),

 

“The most famous such burst, the Cambrian explosion, marks the inception of modern multicellular life. Within just a few million years, nearly every major kind of animal anatomy appears in the fossil record for the first time ... The Precambrian record is now sufficiently good that the old rationale about undiscovered sequences of smoothly transitional forms will no longer wash.” (Stephen Jay Gould, “An Asteroid to Die For,” Discover, October 1989, p. 65),

 

“And we find many of them [Cambrian fossils] already in an advanced state of evolution, the very first time they appear. It is as though they were just planted there, without any evolutionary history. Needless to say, this appearance of sudden planting has delighted creationists.” (Richard Dawkins, The Blind Watchmaker London: W.W. Norton & Company, 1987, p. 229),

 

“One of the major unsolved problems of geology and evolution is the occurrence of diversified, multicellular marine invertebrates in Lower Cambrian rocks on all the continents and their absence in rocks of greater age.” (I. Axelrod, “Early Cambrian Marine Fauna,” Science, Vol. 128, 4 July 1958, p. 7)

 

2. how many similarities in genetic chemistry lie between the pig and man,

or in other species and man. since genes are the pattern being used for the production of living things, are not there more similarities in gene chemistry across species than dissimilarities?

 

3. it seems that man was meant to be man and apes were meant to be

apes. after the split 6 million years ago, there is no evidence of the two species recombining even though the chance existed.

 

4. each branch of the tree has had 6 million years after the split. man advanced mentally and became a master of tools, technology, and thought.

in the same 6 million years the ape is still an ape. does this show good evolution?

[CraigD]

My complements to MortenS for his biological expertise, and questor for his good and civil manner. Gentle chiding to InfiniteNow and orbsycli for comparing Q to a blind man – name-calling, even of the mild sort, though it can feel satisfying, rarely furthers an educational discussion.:eek:

4. each branch of the tree has had 6 million years after the split. man advanced mentally and became a master of tools, technology, and thought.

in the same 6 million years the ape is still an ape. does this show good evolution?

Perhaps gene sequencing and bioinformatics will eventually be able to answer these questions with satisfying, quantifiable precision. For now, however, I think expert and dabbler alike can only speculate as to why we humans have written language, agriculture, nuclear energy and space travel, while our closes genetic cousins have a few hundred vocalizations and gestures, a knack for arranging broad leaves over their heads to deflect rain, and for stripping leaves from stick to dig ants from their mounds.

 

May different lines of speculation converge on the dramatic difference human and other primate aptitude for language. While a great ape can be taught human sign language, and develop an impressively large vocabulary and practical ability to communicate with it, these apes have not show signs of the human aptitude for syntax – consistently putting signs or words in a “right” order. Some studies have suggested that some bird species, such as parrots, have a better innate grasp of syntax than apes.

 

Even many severely mentally handicapped humans, who’s problem solving skills test below those of an ape, have language syntax skills much superior to the an ape’s. This is true also for rare “feral children”, who, by mishap or abuse, are not exposed and taught language. It’s evident that the difference between human and ape language ability is not so much one of “raw intelligence”, but some collection of specialized mental abilities related to language.

 

Speculation for why this is varies, and includes some wild, fringe ideas, such as angels breeding with, or “ancient astronauts” genetically meddling with, some pre-human hominid.

 

:hihi: A less wild line of speculation I find compelling is that, as ancient hominids gained their characteristic upright stance, with the resulting shift in the attachment of spine to skull and lengthening of the trachea. This longer trachea, with its larger larynx, resulted in an animal with better ability to vocalize than non-upright apes. This “improvement” – initially less significant than the vision and reach advantages of standing upright – resulted in a new range of behaviors – calling, singing, etc. – that could be selected for. Individuals and groups who made good advantage of this ability prospered and became genetically dominant in the population. Neurological structure for using this improved larynx by allowing the animal to produce distinct, repetitive sounds were reinforced, and became dominant. Eventually, this talent for repetitive sound-making became a language characterized by a critical dependence on word order (syntax).

 

This line of speculation also suggests an explanation for why some bird species much less similar to humans than the apes appear to have a better aptitude for syntax than the apes. These birds also have unusually capable larynxes, and brain structures that allow them to learn and produce distinct, repetitive sounds.

[coldcreation]

Wow, this thread rules.

 

I will read it fully, then try to jump in. I will first have to brush up on my biology (I was a bio major a while back).

 

Last time I jumped in I got my feathers snipped.

But they are slowly growing back.

 

My idea was that not only are mutations responsible for evolution, but will power (to a certain extent), and foremost action. Without action, and repetition of that action, little will change.

 

A finch dips his beak into a deep flower and can hardly get to the nectar. His actions eventually lead to a physical modification. His beak becomes longer and curved downward. Perhaps the neck too. (Note this is very different than a dog having his tail snipped)

 

I have to explore this further.

 

Now I will read the thread.

 

More soon.

[clapstyx]

For Gods sake does it really matter if if its Divine Evolution towards perfecting the long term survival probabilities of a species or not. The more useful questions that I think science should be asking is what is the logic behind the success of other species in their survival challenge here on Earth..so that we may understand that logic ourselves (even if it is divine) and build as much of that logic as we can into our own existence..hopefully allowing us to benefit from what has been proven over the long term against a measure of life and death in advance of our arrival to a point in time when we need to be formulating a long term survival strategy. Even if we start on it now we will argue about what is the best course of action for a hundred years and by then we are probably going to need it to kick in. Best to base it on the most certain logic we can, even if it happens to be that understanding the logic of symbiotic creation, means we wind up thinking like God once in a while. Isnt that the point of biology..to understand the bio logic. What is it about the crocodile that has allowed it to survive so much longer than all other reptiles..and is there anything in its habits that we can say "Yes that makes sense that a strategy to consume as little energy as possible might allow you to get safely through a period when resources are low".

 

How about we see a bit of human evolution for a change in the form of increased intelligence and consciousness such that one of us might become smart enough to solve the greatest problem that may confront our humanity.

[questor]

the example of the tibetan women shows what about evolution? it demonstrates adaptation, not evolution. are we to suppose that everytime a species needs a longer beak or a larger lung, evolution provides it? please don't use viruses as an example in arguments, they are chameleons of nature taking on host dna. if 98% of all earth life forms are now extinct, neither evolution or adaptation worked well for them. let's demonstrate a new species arising from an old one. wouldn't that really show ''evolve'' ment?

[Biochemist]

.I've been curious about lab experiments, and came across a fellow named Lenski who is putting selection pressures on e.coli cultures. He does genetic assays of his cultures as time goes by, and has observed mutations arising that eventually permiate the cultures. This is a demonstration of advantageous mutations that creationists so often claim is so unlikely as to be nearly impossible. As these are new fuctional genes, they can accurately be described as an addition of information to the organism's genome. Here's his home page, with references to the many papers he's published on his research over the last 20 years: http://www.msu.edu/~lenski/research.html

 

Joel-

 

This is indeed interesting research. I do think that you should keep an open mind to ideas, even if they are offered by a camp with whom you disagree. I generally do not agree with Creationists on much, but it does appear to be true that mutative increases in information load are rare. MortenS has offered examples where the argument can be asserted that genetic information load increases. I have a running dialoge with MortenS that is trying to tease out whether these examples are actually mutative.

 

One issue that I consistently notice in these examples is that authors often presume that "mutation" is the driver for genomic change, as Lenski did in your references. The disturbing element is that often these pleiotropic genetic changes recur when a high-turnover population is re-introduced to a similar stress. I frankly had a hard time assessing whether this was true in Lenski's cases above.

 

If the pleiotropic genetic changes can be reliably duplicated, it strongly suggests that they were not mutations. I have been advocating that there is circumstantial evidence that much of evolutionary progress (perhaps even speciation) is proscribed, not mutative. This would align with a small subset of theistic thinkers, but one ought to evaluate data objectively, not based on the potential impications.

[CraigD]

If the pleiotropic genetic changes can be reliably duplicated, it strongly suggests that they were not mutations. I have been advocating that there is circumstantial evidence that much of evolutionary progress (perhaps even speciation) is proscribed, not mutative. This would align with a small subset of theistic thinkers, but one ought to evaluate data objectively, not based on the potential impications.

I think Biochemist is stating an idea that offers a philosophical solution to the conflict between the teleological assumption (which I consider the parent meme of creationism), and scientific naturalism.

 

That the Creator created only the initial conditions of the universe (via a process only hinted at by current scientific grand theories such as string, brane, etc., which have yet to, and may never, provide adequate testable claims) and that all phenomena since that creation has been entirely natural, is compatible with a wide range of naturalistic and theistic worldviews encompassing most of humankind. It is, IMHO, a position that has served well to allowed Science and Religion to “just get along” as well as they have throughout history (which, despite occasional outbreaks of witch-burning, nihilism, and other woes, has been pretty good), and one reasonable people are well advised to accept now, as opposed to “fundamentalist” stances, either religious or scientific.

 

Note that the bolded assertion above is neither a scientific hypothesis nor a religious creed. It does not require rigorous proof or passionate belief. It is a pragmatic “shared value” that allows human society to function smoothly, allowing both Science and Religion to better achieve their goals.