Fruitflies and Speciation

B

Bridge

Registered Senior Member
Why can't scientists make fruitflies speciate into another insect? They have the shortest life span and have high reproductive rates. One scientist could study thousands of generations worth. Why have all the genetic manipulations to induce speciation failed?

I'm not sayin, I'm just sayin.
 
Forty years of solitude: life-history divergence and behavioural isolation between laboratory lines of Drosophila melanogaster
Boake CRB, McDonald K, Maitra S, Ganguly R
JOURNAL OF EVOLUTIONARY BIOLOGY
16 (1): 83-90 JAN 2003

Abstract:
The study of the early stages of speciation can benefit from examination of differences between populations of known history that have been separated for a short time, such as a few thousands of generations. We asked whether two lines of Drosophila melanogaster that were isolated more than 40 years ago have evolved differences in life-history characters, or have begun to evolve behavioural or postzygotic isolation. One line, which is resistant to DDT, showed lower egg production and a shorter lifespan than a susceptible line. These differences are not a pleiotropic effect of resistance because they are not attributable to the chromosome that contains the resistance factors. The two lines have begun to become behaviourally isolated. Again, the isolation is not attributable to genes on the chromosome that contains resistance factors. The lines show only prezygotic isolation; there is no evidence of reduced fitness of F1 or F2 hybrids. These lines and others like them, should be excellent subjects for analyses of genetic changes that could lead to speciation.

Author Keywords:
Drosophila melanogaster, fecundity, fertility, insecticide resistance, longevity, postzygotic isolation, prezygotic isolation, speciation
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maybe a few 1000 generations is not even enough for the fruitfly


and for yeast i already gave you a reference for speciation in the lab:
Science 2002 Nov 29;298(5599):1773-5
Hybrid speciation in experimental populations of yeast.

Greig D, Louis EJ, Borts RH, Travisano M.

The Galton Laboratory, Department of Biology, University College London, Gower Street, London WC1E 6BT, UK.

Most models of speciation require gradual change and geographic or ecological isolation for new species to arise. Homoploid hybrid speciation occurred readily between Saccharomyces cerevisiae and Saccharomyces paradoxus. Hybrids had high self-fertility (about 82%), low fertility when backcrossed to either parental species (about 7.5%), and vigorous growth under different thermal environments that favored one or the other of the parental species. Extensive karyotypic changes (tetrasomy) were observed in the hybrids, although genic incompatibilities accounted for 50% of the variation in self-fertility.
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but you refuse to believe this i believe, because it says hybrid and that is a dirty word in your dictionary.

speciation in stickelbacks:
Nature 411, 944 - 948 (2001); doi:10.1038/35082064

Divergent sexual selection enhances reproductive isolation in sticklebacks

JANETTE WENRICK BOUGHMAN


Sexual selection may facilitate speciation because it can cause rapid evolutionary diversification of male mating signals and female preferences. Divergence in these traits can then contribute to reproductive isolation1-3. The sensory drive hypothesis predicts that three mechanisms underlie divergence in sexually selected traits4: (1) habitat-specific transmission of male signals5-7; (2) adaptation of female perceptual sensitivity to local ecological conditions8; and (3) matching of male signals to female perceptual sensitivity4, 9. I test these mechanisms in threespine sticklebacks (Gasterosteus spp.) that live in different light environments. Here I show that female perceptual sensitivity to red light varies with the extent of redshift in the light environment, and contributes to divergent preferences. Male nuptial colour varies with environment and is tuned to female perceptual sensitivity. The extent of divergence among populations in both male signal colour and female preference for red is correlated with the extent of reproductive isolation in these recently diverged species. These results demonstrate that divergent sexual selection generated by sensory drive contributes to speciation.
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another interesting one on speciation:
Nature 409, 675 - 677 (2001)

Evolution: Infectious speciation

MICHAEL J. WADE



The bacterium Wolbachia has strange and wonderful effects on reproduction in its many invertebrate host species. In effect, the
creation of new species can now be added to the list.


For a new species to arise, a single population must somehow be split into two reproductively isolated populations that cannot interbreed. Such reproductive isolation usually stems from genetic incompatibility. It is easy to see how that arises when a geographical barrier divides one population of an organism into two, which then diverge genetically. On page 707 of this issue, however, Bordenstein, O'Hara and Werren1 show that in two species of parasitoid wasp it is microbial infection that is the barrier to gene exchange.
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and i was not even trying hard to find anything interesting on speciation...maybe you have more time
 
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Thanks, I might just do that since faith is an inherent component in both these matters.
 
Originally posted by Bridge
Thanks, I might just do that since faith is an inherent component in both these matters.
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you are probably wrong since I am very skeptic of all scientific data, since I produce scientific data myself.
 
The difference is that science is continually evaluating its ideals.

Organized religion doesn'st do this until forced too.
 
squirrel adaptation to climate change

http://archive.newscientist.com/secure/article/article.jsp?rp=1&id=mg17723832.300

a nice example of how fast things can change in evolution, even for mammals. In this case squirrels, or rats with furry tails as some people know them, seem to adapt quite rapidly to the changing climate.

and this quote is especially for neville, because he is interested in human evolution:
The findings add to a body of evidence that animal behaviour is changing in response to global warming. Genetic changes have been found in mosquitoes, for example. But it is unlikely that humans have started to evolve in response to climate change. "We have been able to overcome so many of the selective pressures that would normally be important,"
 
Bridge, a qoute from a theology forum:
"creationism is based on ideology and dogmatism, not on honest inquiry."
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This is the nicest thing I could say about creationism... anything else would be the blunt truth.
 
Fetus states:

>"creationism is based on ideology and dogmatism, not on honest inquiry."

This is the nicest thing I could say about creationism... anything else would be the blunt truth.<"

I guess I'd concur with that sentiment in limited and general terms. Whether one's worldview on the origins question is based on Young Earth Creationism, Old Earth Creationism, Theistic Evolution, Atheistic Evolution, Panspermia, etc., etc. (ie. the notion we popped out of an egg and that we're all riding through the heavens on the back of a giant tortoise), we all seeking answers to questions, some of us just aren't asking the right questions. :)

I personally think evolution is a good theory. It might even be the "correct" theory. I wouldn't bother me the least bit if tomorrow the headlines read, "The Secret to Life Revealed by Evolution" and they had the empirical evidence to back it up. That's fine by me and wouldn't change my faith at all.

The time I have invested in studying the origins debate has revealed to me that there is more than just science being debated on both sides of the creation vs. evolution spectrum. Both sides have some baggage their dragging along. The YECs might stick out like a sore thumb to you and I, but don't think that some of these pariahs haven't brought up valid issues. I may not believe in a 6,000 year old universe or random chemical evolution but I'm willing to listen and evaluate every arguement.

I intend to stay focused on facts and not hyperbole in this arena, always remembering the wisdom behind knowing that all truth, whether scientific or spiritual truth, ultimately comes from the same source.:)
 
I totally agree with that! I feel nothing is for certain and that stubbornness in the infallibility of a belief (either it be sciences or theology) is a sign of foolishness. Everything should be questioned and nothing is final or totally true.
 
i'm kind of confused by the initial question. i can cite quite a few papers on speciation of fruit flies. so...whaaa?:confused:
 
Originally posted by SwedishFish
i'm kind of confused by the initial question. i can cite quite a few papers on speciation of fruit flies. so...whaaa?:confused:
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it is not hard evidence enough according to his standards (which can never be met by science probably)...
 
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