Interesting Evolution and Anthropology News

There is a bunch of interesting news relating to evolution and anthropology.

Ed Yong discusses and interesting new study, published in PNAS, on coloration in lizards at White Sands, New Mexico. I have touched on the subject in a previous post. The paper can be found here for those who have access.

A new type of biological antifreeze has been found in an Alaskan beetle. Unlike previous types, this is not a protein it is composed of a sugar and a fatty acid. From Science Daily:

A possible advantage of this novel molecule comes from it having the same fatty acid that cells membranes do. This similarity, says Barnes, may allow the molecule to become part of a cell wall and protect the cell from internal ice crystal formation. Antifreeze molecules made of proteins may not fit into cell membranes.

Also from Science Daily is an interesting item on orchids that use flowers that look or smell like females to aide pollination:

Schiestl and his team observed populations of 31 orchid species with varying pollination strategies in Italy and Western Australia. They measured the amount of pollen that was taken from each orchid, and the amount of pollen that made it to its intended destination — another orchid of the same species.

They found that populations of sexually deceptive orchids had higher “pollen transport efficiency” than the species with multiple pollinators. In other words, a higher percentage of the pollen that was taken from sexually deceptive orchids actually made it to another orchid of the same species. The orchids with multiple pollinators had more pollen taken from their flowers, but more of that pollen was lost — dropped to the ground or deposited in flowers of the wrong
species.

The paper is here for those who have access.

PLoS has an interesting research paper on cichlid visual pigments. Here is the abstract:

A major goal of evolutionary biology is to unravel the molecular genetic mechanisms that underlie functional diversification and adaptation. We investigated how changes in gene regulation and coding sequence contribute to sensory diversification in two replicate radiations of cichlid fishes. In the clear waters of Lake Malawi, differential opsin expression generates diverse visual systems, with sensitivities extending from the ultraviolet to the red regions of the spectrum. These sensitivities fall into three distinct clusters and are correlated with foraging habits. In the turbid waters of Lake Victoria, visual sensitivity is constrained to longer wavelengths, and opsin expression is correlated with ambient light. In addition to regulatory changes, we found that the opsins coding for the shortest- and longest-wavelength visual pigments have elevated numbers of potentially functional substitutions. Thus, we present a model of sensory evolution in which both molecular genetic mechanisms work in concert. Changes in gene expression generate large shifts in visual pigment sensitivity across the collective opsin spectral range, but changes in coding sequence appear to fine-tune visual pigment sensitivity at the short- and long-wavelength ends of this range, where differential opsin expression can no longer extend visual pigment sensitivity.

Finally, there is an interesting paper in PNAS on the eruption of the first permanent mandibular molar in gorillas and orangutans – well a gorilla and a orangutan so there is no way of determining how much variation there is in eruption times.

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