Evolution

The coffee plant has a newly sequenced genome and that can tell scientists what they really want to know about: the evolution of caffeine.

The sequences and positions of genes in the coffee plant show that they evolved independently from genes with similar functions in tea and chocolate, which also make caffeine. Coffee did not inherit caffeine-linked genes from a common ancestor, but instead developed the genes on its own.

Why Coffee?


In 1986, an expedition off the South-East coast of Australia near Tasmania, from depths of between 400 and 1,000 metres, brought up some jelly-like creatures, which were seen to be unusual and immediately preserved in ethanol. Now they have been examined, and assigned to a new genus Dendrogramma (from their resemblance to a tree diagram), with two species D. enigmatica and D. discoides.

Most living mammals are nocturnal and it has long been thought that the transition to nocturnality occurred at about the same time as mammals evolved, around 200 million years ago. That hypothesis was based on features such as the large brains of mammals (good for processing information from senses like hearing, touch, and smell) and the details of light-sensitive chemicals in the eyes of mammals.

It turns out that nocturnal activity might have a much older origin among ancient mammal relatives, called synapsids.


Why wild animals genetically changed into domesticated forms has long been a mystery, covered by the blanket artificial selection reasoning.

A new paper in Science says that many genes controlling the development of the brain and the nervous system were particularly important for rabbit domestication. 


Although separated by hundreds of millions of years of evolution, flies, worms, and humans share ancient patterns of gene expression and it's all in our genomic data.

Three related studies in Nature, tell a similar story: even though humans, worms, and flies bear little obvious similarity to each other, evolution used remarkably similar molecular toolkits to shape them.

There are dramatic differences between species in genomic regions populated by pseudogenes, molecular fossils of working genes, according to Yale authors in Proceedings of the National Academy of Sciences.


Organisms in a symbiotic relationship will often shed genes as they come to rely on the other organism for crucial functions but researchers have uncovered an unusual event in which a bacterium that lives in a type of cicada split into two species - doubling the number of organisms required for the symbiosis to survive.


If you capture a hummingbird on high-speed video and slow it down, their wings thrum like helicopter blades as they hover near food. Their hearts beat 20 times a second and their tongues dart 17 times a second to slurp from a feeding station.


Humans don't want to live above the West Antarctic ice sheet but microbes can certainly live below it, according to a new study. Even half a mile below it.

The waters and sediments of a lake 2,600 feet beneath the surface of the West Antarctic ice sheet support "viable microbial ecosystems", according to recent results. Given that more than 400 subglacial lakes and numerous rivers and streams are thought to exist beneath the Antarctic ice sheet, such ecosystems may be widespread and may influence the chemical and biological composition of the Southern Ocean, the vast and biologically productive sea that encircles the continent.



The small body size associated with the African pygmy phenotype is probably a selective adaptation for rainforest hunter-gatherers, according to a new study, but since all African pygmy phenotypes do not have the same genetic underpinning it is likely a more recent adaptation than previously thought, according to a new paper in the Proceedings of the National Academies of Science.

 A phenotype is the outward expression of genetic makeup and while two individuals with the same phenotype may look alike, their genes may differ substantially. The pygmy phenotype exists in many parts of Africa, Southeast Asia, the Philippines and perhaps South America and is usually associated with rainforest hunter-gathers rather than people who farm.