- antibiotic resistance in bacteria
- new strains of the flu
- Multiple new strains of HIV in a person. In fact, the variation among strains of HIV within a single person exceeds the variation of the flu over several years by several order of magnitude!
- pesticide resitance in insects
- fungicide resistance in weeds
- Human bones becoming stronger (
High Bone Density Due to a Mutation in LDL-Receptor—Related Protein 5 | NEJM)
- Adaptation to High and Low Temperatures by E. coli.
quote:
A single clone of E. coli was cultured at 37 C (that is 37 degrees Celsius) for 2000 generations. A single clone was then extracted from this population and divided into replicates that were then cultured at either 32 C , 37 C, or 42 C for a total of another 2000 generations. Adaptation of the new lines was periodically measured by competing these selection lines against the ancestor population. By the end of the experiment, the lines cultured at 32 C were shown to be 10% fitter that the ancestor population (at 32 C), and the line cultured at 42 C was shown to be 20% more fit than the ancestor population. The replicate line that was cultured at 37 C showed little improvement over the ancestral line.
Bennett, A.F., Lenski, R.E., & Mittler, J.E. (1992). Evolutionary adaptation to temperature I. Fitness responses of Escherichia coli to changes in its thermal environment. Evolution, 46:16-30.
And my personal favorite, the story of
Chlorella Vulagris
quote:
Predation was a powerful selective force promoting increased morphological complexity in a unicellular prey held in constant environmental conditions. The green alga, Chlorella vulgaris, is a well-studied eukaryote, which has retained its normal unicellular form in cultures in our laboratories for thousands of generations. For the experiments reported here, steady-state unicellular C. vulgaris continuous cultures were inoculated with the predator Ochromonas vallescia, a phagotrophic flagellated protist ("flagellate"). Within less than 100 generations of the prey, a multicellular Chlorella growth form became dominant in the culture (subsequently repeated in other cultures). The prey Chlorella first formed globose clusters of tens to hundreds of cells. After about 10-20 generations in the presence of the phagotroph, eight-celled colonies predominated. These colonies retained the eight-celled form indefinitely in continuous culture and when plated onto agar. These self-replicating, stable colonies were virtually immune to predation by the flagellate, but small enough that each Chlorella cell was exposed directly to the nutrient medium. --Changes
quote:
this mutation provided Chlorella with resistance to predation at the cost of growth rate. Neonatal colonies are barely small enough for Ochromonas to engulf. After they have grown slightly they are to big to be eaten. In the presence of the predator, the colonial form of Chlorella displaces the unicellular form and persists. When the predator is not present, the unicellular form displaces the colonial form. This makes sense as the colonial form has less surface area exposed to the environment available for nutrient uptake than the unicellular form has.
quote:
Coloniality in Chlorella vulgaris
Boraas (1983) reported the induction of multicellularity in a strain of Chlorella pyrenoidosa (since reclassified as C. vulgaris) by predation. He was growing the unicellular green alga in the first stage of a two stage continuous culture system as for food for a flagellate predator, Ochromonas sp., that was growing in the second stage. Due to the failure of a pump, flagellates washed back into the first stage. Within five days a colonial form of the Chlorella appeared. It rapidly came to dominate the culture. The colony size ranged from 4 cells to 32 cells. Eventually it stabilized at 8 cells. This colonial form has persisted in culture for about a decade. The new form has been keyed out using a number of algal taxonomic keys. They key out now as being in the genus Coelosphaerium, which is in a different family from Chlorella. "
Boraas, M. E. 1983. Predator induced evolution in chemostat culture. EOS. Transactions of the American Geophysical Union. 64:1102
And I found all this within 10 minutes of surfing the net, and remembering some of my
high school biology classes. It astounds me that someone can reject one of the most well supported theories of the last hundred years without doing even 20 minutes of research, or educating oneself about the subject. Here is a nice quote which you would do well to remember:
quote:
Often a non-Christian knows something about the earth, the heavens, and the other parts of the world, about the motions and orbits of the stars and even their sizes and distances,... and this knowledge he holds with certainty from reason and experience. It is thus offensive and disgraceful for an unbeliever to hear a Christian talk nonsense about such things, claiming that what he is saying is based in Scripture. We should do all that we can to avoid such an embarrassing situation, which people see as ignorance in the Christian and laugh to scorn.
--St. Augustine
"Knowledge is Power" - Francis Bacon
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