Biology news

Mass Extinctions and Evolution

Again, at www.wired.com/wiredscience/2010/09/mass-extinction-dynamics/ this story is a repeat - but worth repeating. A reappraisal of the fossil record, it is thought, reveals that global mass extinction events are not actually short term diversions along life's uniformitarian course but such events send life careering down wholly new avenues.

Panspermia - some cold water

At http://lifeunbounded.blogspot.com/2010/08/panspermis-paradox.html is a post on panspermia, 'The Panspermia Paradox' (August 19th) ... the notion of panspermia, the transfer of viable organisms between planets and even star systems is discussed from what appears to be a neutral position. Planetary surface material such as dust grains and rocks is continually being shipped around moons and rocky planets in the solar system or ejected by comets and asteroids.

Kangaroos

At www.physorg.com/print200126874.html there is a claim that the evolution of kangaroos was intricately tied to Australian climate change - but suitably confined to millions of years ago rather than anything to do with modern greenhouse gas emissions. The Zoological Journal of the Linnean Society (August 2010) claims the appearance of kangaroos, wallabies, and similar animals occurred millions of years ago when they foraged on soft leaved forest growing plants.

Bacteria is complicated stuff, don't you just know ...

At www.physorg.com/print198148074.html we learn that bacteria is proving to be more complex than scientists have thought previously - just another surprise nature has sprung on the considered opinion of a scientific discipline. A paper in Molecular Microbiology describes an example of that complexity as a molecular reaction inside the cell involving proteins. It modifies and thuse affects the function of those proteins - including the mechanism responsible for turning genes on and off.

Plant genes

www.physorg.com/print197739400.html is a story about how it is thought the wild grass teosinte developed into corn (maize). Experiments in domestication have shown it is possible that domestic plants took fewer than 20 generations to take place - a very short space of time. This appears to contradict the archaeology and this article is a bit of a fight-back by palaeo-botanists against geneticists.

Studies of Fossils

www.physorg.com/print195831471.html June 15th ... reports on attempts to extract further information from fossilised creatures - the behaviour of ancient life forms. I don't know if there is sleight of hand involved here but instead of using fossils as a means of classifying and cataloguing the diversity of life in the past scientists are looking at the possibility of discovering clues about behaviour from that frozen moment of death. Insects caught in amber is one example given.

Shimmering Butterflies

I was watching BBCs 'Springwatch' a couple of days ago and Chris Packham mentioned that the colours of butterflies are produced not by pigments but by a special geometric formation of cells, that shimmer and give the illusion of colour.

The Iowa Cicada

At www.physorg.com/print194880259.html ... there is a story about the rare appearance of the cicada, an insect, in Iowa - that is supposed to appear at 17 year intervals. Why?

Termites in the Savannah Belt

At www.sciencedaily.com/releases/2010/05/100525171229.htm a paper published by PLoS Biology says that termites are typically viewed as pests and as threats to agricultural and livestock production - and termite mounds are often destroyed. However, it has been found it can take centuries to build up a single termite mound and field research in Kenya has found they form a network of uniformly distrubuted mounds across the savannah environment.

Oxygen and Evolution

At www.physorg.com/print192714427.html - the journal Astrobiology has a paper that suggests the evolution of complex life forms may have had a kickstart a couple of billion years ago when geological events caused large quantities of phosphorous to wash into the oceans. In turn, this caused vast algal blooms that pumped extra oxygen into the environment which allowed larger more complex organisms to thrive.