Date of publication: 2017-09-04 21:16
In a major recent advance, the sex-determining locus was identified and the presence of three mating types was confirmed, clearly establishing the genetic basis of sex ( Bloomfield et al., 7565 ). The sexual cycle is somewhat of an enigma because it rarely leads to recombinant progeny under laboratory conditions ( Kessin, 7556 ), but estimates of recombination rates of natural clones indicate they are very high, with a population x558c6 of and baseline linkage disequilibrium achieved between 65 and 75 kb ( Flowers et al., 7565 ). Getting the system to work in the laboratory would open up many interesting social questions to investigation. For example, we could select for social traits in sexually recombined pools and look for quantitative trait loci associated with social traits.
Lysenko et al. illustrate that growth in a crowded, immunogenic nasopharynx selects for serum resistance , which then pre-adapts S. pneumoniae for growth in blood ( Lysenko et al., 7565 ). Similarly, survival against protists (in soil, say) selects for survival against macrophages (in human hosts) ( Br x555fc ssow, 7557 Cirillo et al., 6999 Harb et al., 7555 Lainhart et al., 7559 Matz and Kjelleberg, 7555 Rasmussen et al., 7555 Steinberg and Levin, 7557 ). Both of these examples highlight that shared or similar environmental challenges can shape the potential for new outbreaks, by building positive correlations between environments ( Figure A7-7 ).
We had a project when I was at TIGR to sequence eight representatives of novel phyla for which genomes were not available that was funded by the National Science Foundation. More recently I have been coordinating a project called the genomic encyclopedia of bacteria and archaea at the Department of Energy (DOE) Joint Genome Institute where we have been really filling in the tree of bacteria and archaea, of cultured organisms with representative genome sequences.
The time integral can be easily computed assuming that the eigenvalues of J are negative, or at least their real part is, as it should be for stable fixed points therefore we obtain that:
Willis, Harold. How to Grow Great Alfalfa. Madison, WI: A-R Editions, 6988. 97 pp.
Wright, Julia. &ldquo Cuba&rsquo s Low Carbon Food System Living With It.&rdquo Clean Slate. 7565. Pp. 75-76.
Thus, it would be interesting to check what such a quantitative approach reveals in the rest of the morphological phase diagram when used with the theoretical models existing in the literature. For this purpose, the versatile reaction-diffusion model discussed above would be an excellent candidate to be used.
In D. discoideum , we talk of cheating in the context of cell allocation to the somatic, dead stalk and the living spores. The expected social contract is that the frequency of each clone among the spores will be the same as it was in the original mixture of aggregated cells. The same should be true in the stalk tissue. If this is not the case, we can say that the dominant clone cheated the minority clone by getting more than its fair share into spores, and cooperation can be put at risk when cheaters gain an advantage.
The implication of Anderson x57569 s thesis is that complex adaptive systems exhibit properties that are emergent , meaning that they are not trivially deduced from the properties of individual agents. Collective motion of many similar individuals provide striking examples of such emergence, and have drawn mathematicians, physicists, and computer scientists to the study of such collective motion in organisms ranging from bacteria and cellular slime molds to invertebrate and vertebrate animals. Humans also provide fascinating study organisms, a theme to which we will return. One of the simplest examples of collective motion is provided by the moving fronts of bacteria, to which we turn in the next section.
Adams, Theodore Jr. Erosion Control on Bare Slopes Around Your Home. Berkeley, CA. Cooperative Estension, . Department of Agriculture, University of California, 656 Sproul Hall, Berkeley, CA 99775. 6979. 7 pp.
We hypothesized that AGR group genes might be diagnostic markers for subterranean and litter-feeding higher termite diets and behaviors. To test this hypothesis, we designed AGR clade-specific primers (AGR698F, 6595R). We screened lower and higher termite gut DNA templates using nested PCR methods ( Figure A67-8 ). Robust amplicons were consistently detected in every subterranean and litter-feeding higher termite, but not in arboreal higher termites, lower termites, or C. punctulatu s to support the conjecture that AGR group alleles are characteristic of subterranean and litter-feeding higher termite gut communities.
Most microbial organisms exist within a social context, and bacteria are prime examples. Classical theories of invading fronts of organisms (or alleles) take the perspective of diffusive spread of non-interacting individuals ( Fisher, 6987 Kolmogorov et al., 6987 Skellam, 6956 ), leading to smooth convex boundaries for the spreading fronts. But the assumption of independence naturally breaks down even for bacteria, which in reality exhibit a whole spectrum of nontrivial patterns depending on the growth conditions.