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| 5/25 |
| 2008/6/9-12 [Science/Biology] UID:50196 Activity:nil |
6/9 Evolution in E. Coli observed in the lab:
http://preview.tinyurl.com/4kdx4b [new scientist]
\- The Finger of God! ... or at least the Middle Finger
to ID nutjobs.
\_ You mean God can't change His design on the fly? PMs in my
company do it all the time ...... -- grouching engineer
\_ Creationism holds that all things great and small were
created in their current forms without provision for
change.
\_ Some flavors do. Most creationists accept
micro-evolution, while rejecting macro-evolution. Some
accept both. "Young Earth" creationists believe the Earth
is no more than 6,000 years old. -emarkp
\_ you mean, "some creationists invented the concept of
'macro-evolution' as a way of maintaining the absurd
position that there is something fundamental to
object to in evolutionary theory." -tom
\_ Roughly, yes. Strictly they refer to
"macro-evolution" to mean speciation arising such
that the new species can't breed with another branch
of the evolutionary tree. So called
"micro-evolution" just means variations being
preferred inside the same species (the peppered moths
being the perfect example). -emarkp
\_ So do they think that lions and tigers have a
common ancestor? They can breed, but the
offspring generally can't.
\_ I'm not a spokesman of the ID community, and I
honestly don't know how they'd respond to that
question. -emarkp
\_ This is news why? There have been many observed examples
of evolution, and many observed examples of even speciation,
and ID-ers and creationists are happily ignoring all that
evidence. Why is this story special?
\_ we thought evolution took millions of years.. not days..
why did it take so long to create man from single celled
according to the new findings it should take at most
6 thousand years..
\_ I guess it's because as an organism becomes more complex, the
generation span becomes longer (around 25.2yrs in 2004 for US
humans ignoring age of fathers (http://www.csua.org/u/lqi
vs. minutes or hours or days for bacteria).
\_ The interesting thing to me is not the ID angle but the
way the researchers were able to figure out around which
generation the new mutation occured and how the research
shows that history dictates what abilities emerge.
\_ There is a group of ID people that can be reached by stories
like this. Some will ignore it, just like the global warming
believers. |
| 5/25 |
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| preview.tinyurl.com/4kdx4b -> www.newscientist.com/channel/life/dn14094-bacteria-make-major-evolutionary-shift-in-the-lab.html?feedId=online-news_rss20 Advertising A major evolutionary innovation has unfurled right in front of researchers' eyes. It's the first time evolution has been caught in the act of making such a rare and complex new trait. And because the species in question is a bacterium, scientists have been able to replay history to show how this evolutionary novelty grew from the accumulation of unpredictable, chance events. Richard Lenski of Michigan State University in East Lansing, US, took a single Escherichia coli bacterium and used its descendants to found 12 laboratory populations. The 12 have been growing ever since, gradually accumulating mutations and evolving for more than 44,000 generations, while Lenski watches what happens. Profound change Mostly, the patterns Lenski saw were similar in each separate population. All 12 evolved larger cells, for example, as well as faster growth rates on the glucose they were fed, and lower peak population densities. But sometime around the 31,500th generation, something dramatic happened in just one of the populations the bacteria suddenly acquired the ability to metabolise citrate, a second nutrient in their culture medium that E coli normally cannot use. Indeed, the inability to use citrate is one of the traits by which bacteriologists distinguish E coli from other species. The citrate-using mutants increased in population size and diversity. "It's the most profound change we have seen during the experiment. This was clearly something quite different for them, and it's outside what was normally considered the bounds of E coli as a species, which makes it especially interesting," says Lenski. By this time, Lenski calculated, enough bacterial cells had lived and died that all simple mutations must already have occurred several times over. That meant the "citrate-plus" trait must have been something special either it was a single mutation of an unusually improbable sort, a rare chromosome inversion, say, or else gaining the ability to use citrate required the accumulation of several mutations in sequence. To find out which, Lenski turned to his freezer, where he had saved samples of each population every 500 generations. These allowed him to replay history from any starting point he chose, by reviving the bacteria and letting evolution "replay" again. Would the same population evolve Cit+ again, he wondered, or would any of the 12 be equally likely to hit the jackpot? Evidence of evolution The replays showed that even when he looked at trillions of cells, only the original population re-evolved Cit+ and only when he started the replay from generation 20,000 or greater. Something, he concluded, must have happened around generation 20,000 that laid the groundwork for Cit+ to later evolve. Lenski and his colleagues are now working to identify just what that earlier change was, and how it made the Cit+ mutation possible more than 10,000 generations later. In the meantime, the experiment stands as proof that evolution does not always lead to the best possible outcome. Instead, a chance event can sometimes open evolutionary doors for one population that remain forever closed to other populations with different histories. Jerry Coyne, an evolutionary biologist at the University of Chicago. "The thing I like most is it says you can get these complex traits evolving by a combination of unlikely events," he says. Comment subject Comment No HTML except lower case italic tags or lower case bold tags, please: <i> or <b> Your name Your email We need your email in case we need to contact you about the comment. VIEW THREAD >> Creationists By Robin Blick Mon Jun 09 23:29:47 BST 2008 More proof, if any were needed, that Darwin is right, and the God squad wrong. the truth is to be found in the holy texts, and not laboratories. By Tom Mon Jun 09 23:50:27 BST 2008 It's amazing that Lenski has been running this experiment for 20 years, and how wonderful for him that his experiment has borne such interesting fruit. If he can identify the mutations that took place around gen 20,000 and how they laid the groundwork for the development of Cit+, it could be an insight as significant as Mendel's experiments with peas. If Lenski does it, he deserves a prize, maybe the Nobel itself, for insights into evolution. |
| www.csua.org/u/lqi -> www.census.gov/Press-Release/www/releases/archives/facts_for_features_special_editions/009747.html While the annual celebration spread around the country, Jarvis began lobbying politicians to set aside a day to honor mothers. She finally succeeded in 1914, when Congress designated the second Sunday in May as Mother's Day. htm> 25 Average number of children that women in Utah can expect to have in their lifetime. This state tops the nation in average number of births per woman. Rhode Island, Vermont, Massachusetts and the District of Columbia have the lowest average number -- 17 births. pdf> Mothers Remembered 21,667 Number of florist establishments nationwide in 2004. The 109,915 employees in floral shops across our nation will be especially busy preparing, selling and delivering floral arrangements for Mother's Day. html> The flowers bought for mom have a good chance of having been grown in California. Among the 36 surveyed states, California was the leading provider of cut flowers in 2005, accounting for 73 percent of domestic flower production ($289 million out of $397 million) in those states. docu mentID=1072> Months ahead of this widely observed day of recognition, many of the 13,057 employees of the 120 greeting-card publishing establishments in 2004 would have been busy creating Mother's Day greeting cards. html> Moms Who've Recently Given Birth 41 million Number of births in the United States in 2005. Of this number, 414,406 were to teens 15 to 19, and 111,190 to moms 40 or older. html> 729,040 Number of child care centers across the country in 2004. These include nearly 72,000 centers employing close to 780,000 workers and another 657,000 self-employed persons or other companies without paid employees. Many mothers turn to these centers to help juggle motherhood and career. html> Meals with Mommy 61% and 81% Percentages of children younger than 6 living with married parents who eat breakfast and dinner, respectively, with their mother every day. The corresponding percentages who eat with their father were 30 percent and 64 percent. html> Following is a list of observances typically covered by the Census Bureau's Facts for Features series: Black History Month (February) Valentine's Day (Feb. Patrick's Day (March 17) Asian/Pacific American Heritage Month (May) Older Americans Month (May) Mother's Day (May 13) Father's Day (June 17) The Fourth of July (July 4) Anniversary of Americans with Disabilities Act (July 26) Back to School (August) Labor Day (Sept. Questions or comments should be directed to the Census Bureau's Public Information Office: telephone: 301-763-3030; |