Almost all mutations which aren't silent and which aren't eliminated immediately are neither completely advantageous nor deleterious. ... Commonly, but not always, these mutations decrease the fitness of the bacteria, i.e., in environments where there are not antibiotics present, they don't reproduce as quickly as...
www.talkorigins.org/faqs/mutations.html www.talkorigins.org/faqs/mutations.html
Most mutations are neutral. Nachman and Crowell estimate around 3 deleterious mutations out of 175 per generation in humans (2000). Of those that have significant effect, most are harmful, but the fraction which are beneficial is higher than usually though.
www.talkorigins.org/indexcc/CB/CB101.html
Obviously mutations can indeed cause dramatic phenotype change from environmental pressures. Many experiments have been performed on fruit flies (Drosophila) where poisons and radiation induced mutations. However, the problem is that they are always deleterious.
creationwiki.org/Mutations creationwiki.org/Mutations
At 15% the computer says the other allele will almost always win - if our slightly deleterious allele gets no boost from being linked to a selected gene or spread by a popular sire. However, ... 2. We can explain to breeders that mutations will always be with us, and are not an indication of failure or bad breeding practice,
www.canine-genetics.com/Mutation.htm www.canine-genetics.com/Mutation.htm
The problem with it is that we have never been able to observe a positive mutation. Mutations are always deleterious (negative). A chromosome-damaged offspring is always less well adapted for life than the ancestor.
www.mazeministry.com/resources/books/hardcasetext/hardc... www.mazeministry.com/resources/books/hardcasetext/hardcase9.htm
; From: University of North Carolina School of Medicine; Gene mutations not always expressed as complete disease ... "Advanced molecular techniques provide a double-edged sword because they often detect sequence changes [mutations in genes] whose deleterious effects are by no means established," they write.
www.scienceblog.com/community/older/1999/D/199903921.ht... www.scienceblog.com/community/older/1999/D/199903921.html
Having a harmful effect; injurious: the deleterious effects of smoking. ... Wordsmith Words: deleterious ... Are mutations always deleterious?
www.answers.com/topic/deleterious www.answers.com/topic/deleterious
Orr, an associate professor of biology, likens Fisher's belief that major mutations are always deleterious to random tinkering with the innards of a television.
www.rochester.edu/pr/releases/bio/orr.htm
Mutations happen all the time, and yes, most are either deleterious or innocuous, that is to say, they don't produce any change. But, I'll give you ... I'm fed up with creationists saying mutations are always deleterious. Surely there must be at least on recorded example of a benign mutation (in the lab or something).
answers.yahoo.com/question/index?qid=20070913113824AAhc... answers.yahoo.com/question/index?qid=20070913113824AAhcFGn
Tim Wallace responds to Tom Schneider's critical ''summary'' of their exchange on thermodynamics and more. ... The most blatant attempt was to assume that mutations are always deleterious. This is a clear case of assuming what he wants to prove (that information gain is impossible because genetic sequences would always decay).
www.trueorigin.org/ca_tw_01.asp