Month: September 2022

GRADUAL PHYLOGENY. “The model parameters fitted to observed patterns show a substantial phylogenetic signal, indicating that the processes governing evolutionary change in shell patterns are, to some extent, gradual across the phylogeny.” https://lnkd.in/dwfZQzE View in LinkedIn

First magical snowdrops of the year. View in LinkedIn

SHELL PATTERNINGS. “Our analyses have allowed us to estimate the shell pigmentation patterns of ancestral species, identify lineages in which one or more parameters have evolved rapidly, and measure the degree to which different parameters correlate with the phylogeny.” https://lnkd.in/dwfZQzE View in LinkedIn

DISCONNECT OVER GENERATIONS. “A unique feature of our results is that the inferred pigmentation patterns of ancestors may be quite different from the patterns of their descendants.” https://lnkd.in/dwfZQzE View in LinkedIn

STEPWISE PATTERNINGS. “The patterns generated by the neural-network model are not necessarily smooth functions of the parameter values. Instead, they can vary discontinuously when parameter values move into a different bifurcation region that produces qualitatively different patterns.” https://lnkd.in/dwfZQzE View in LinkedIn

BINARY OUTCOMES. “The role of bifurcation boundaries in evolution was recognized in earlier studies of limb morphogenesis. This feature of our results is quite different from what is usually found when inferring ancestral states of continuously variable characters. A well known limitation of methods for estimating ancestral states is that it is impossible for estimates to fall outside the range of the living species analyzed.” https://lnkd.in/dwfZQzE View in LinkedIn

BIFURCATION BOUNDARIES. “This limitation does not apply to pigmentation patterns. Although the same averaging procedure is being used on each parameter of the neural-network model, it is possible, and even likely, that a set of estimated parameters will be in a region of parameter space not inhabited by any living species.” https://lnkd.in/dwfZQzE View in LinkedIn

NON-HOMOGENEOUS EDDIES. “The sensitivity of the neural network to perturbations means that small, gradual evolutionary shifts in one or a few parameters of the neural network can shift a shell from one pattern regime into an entirely dissimilar one.” https://lnkd.in/dwfZQzE View in LinkedIn

PHYLOGENETIC SIGNAL. “We found phylogenetic signal in the continuous parameters of the primary neural network and in the presence/absence of a hidden network, suggesting that the model reasonably approximates the developmental processes underlying pigmentation patterns in the Conus species we considered. In contrast, various features of the pigmentation patterns, such as the presence of stripes and dots, do not have significant phylogenetic signal.” https://lnkd.in/dwfZQzE View in LinkedIn

UV LIGHT HISTORIES. “Unlike their modern relatives, the 4.8-6.6 million-year-old fossil cone shells often appear white and without a pattern when viewed in regular visible light. By placing these fossils under ultraviolet (UV) light, the organic matter remaining in the shells fluoresces, revealing the original coloration patterns of the once living animals. However, it remains unclear which compounds in the shell matrix are emitting light when exposed to UV rays.” https://lnkd.in/dUkV8Fr View in LinkedIn