Trees of Life

17 Apr 2020

ASt ... researchers challenge the accuracy of methods that analyse trees of life. The paper is published in Nature (April 2020). Two scientists argue that long used approaches for reconstructing trees of life are 'deeply flawed'. The findings cast 'serious doubt' over thousands of earlier studies that use phylogenetic trees of extent data to reconstruct the diversification history of taxa - especially those taxa where fossils are rare. In addition, they add, where correlates have been made between environmental factors such as changing global temperatures and species extinction rates. The authors are evolutionary biologists so nothing dramatic is being suggested. Sounds good though.

At ... evolutionary biologists again. Bees point to new evolutionary answers - but do they. How do you explain how new species arise and evolve to occupy niche environments within Gaia (mother nature). Bees found on Fiji (in the highlands) seem to provide evidence that they have evolved into many species - in spite of the fact they cannot readily adapt to different habitats. Don't get too excited.

At ... the mahogany tree family dates back to the last hurrah of the dinosaurs. Or, to put it another way, mahogany trees were around during the Late Cretaceous era (just prior to the K/T boundary event). In other words, the fruit of mahogany trees (fossilised) were found in sediments just before the K/T boundary event. The fossil clue to the mahogany family of trees was found in rocks just off Vancouver Island. It was collected by a local fossil hunter and eventually fell into the hands of scientists who were surprised that mahogany trees were contemporary with the dinosaurs. This finding comes on the heels of other surprising finds and may just tell us something about the first story - how the trees of life are constructed. The dinosaur age is more famous for its gingkos and tree ferns (and fern species in general). Next they'll be telling us there were oak trees too. You never know.

One other point. Nowadays mahogany trees grow in Amazonia - in the tropics. The implication here is that Vancouver Island was once very close to the equator. No wonder there were trees growing on Ellesmere Island in Arctic Canada.