A previous study revealed higher rate of constrained site evolution within a penguin lineage compared with that estimated between the lineages (Subramanian et al. 2009).
Allocation of funds towards provision of transportation and affordable housing infrastructure and/or mitigation must be balanced against design and constructability decisions (constrained site construction and demolition challenges, quality of building materials, lighting, etc)., allocations of uses, parking and open/street spaces and vegetation.
They suggested that the pre-war shopping area should be set aside as a civic area with perhaps a concert hall or similar building and an open space, and that the central shopping area should be moved to a less-constrained site.
Population genetic theories predict a time-dependent rate at constrained sites (but not at neutral sites) due to the removal of slightly deleterious mutations over time.
This allows for greater overall flux between states and thus a higher rate of substitution at the constrained sites compared with the neutrally evolving sites.
Figure 1 A shows the ratio of the average rate of substitution per site in equilibrium at constrained sites, r, and at neutral sites, r0, in this scenario (Materials and Methods).
Our results revealed an order of magnitude variation in the evolutionary rates at constrained sites (including nonsynonymous sites, D-loop, and RNA) and virtually an identical rate of evolution at synonymous sites, independent of the timescales over which they were estimated.
The real situation could probably be more complex, as a duplicate that is not important for the function will tend to be less constrained (some proteins are more constrained than others; environmental proteins may have less constrained sites).
At constrained sites, however, it assumes the wrong equilibrium frequencies.
This can be seen in figure 1 B where the expected equilibrium A/T content at the constrained sites, ρA+T, is plotted for the strength of purifying selection yielding the maximal rate acceleration for a given mutational bias πA+T.
