Evolution


By Sarah King, Genetic Literacy Project

Since the discovery in 2004 of Homo floresiensis, an ancient hominid nicknamed “Flo” and also “hobbit”, after the diminutive villagers from J.R.R. Tolkien’s Lord of the Rings trilogy, due to her small size relative to modern humans, much debate has been raised over the origins of the species.

Scientists have documented the rapid evolution of a native lizard species as a result of pressure from an invading lizard species introduced from Cuba. 

After contact with the invasive species, the native lizards began perching higher in trees, and, generation after generation, their feet evolved to become better at gripping the thinner, smoother branches found higher up. It only took about 20 generations - 15 years - but even within a few months, native lizards had begun shifting to higher perches and as time passed their toe pads had become larger, with more sticky scales on their feet.


Though Ebola tends to occur in waves, the filoviruses family to which Ebola and its lethal relative Marburg belong, are at least 16 million years old.

Filoviruses likely existed in the Miocene Epoch, and at that time, the evolutionary lines leading to Ebola and Marburg had already diverged, according to a paper inl PeerJ. It was once believed that the viruses only came into being some 10,000 years ago, coinciding with the rise of agriculture but now it is believed to have developed at the time when great apes arose.


How did life originate? And can scientists create life? These questions have always occupied philosophers and scientists interested in the origin of life, and they impact technology of the future also.

If we can create artificial living systems, we may not only understand the origin of life - we can also revolutionize the future of technology.

Protocells are the simplest, most primitive living systems, you can think of. The oldest ancestor of life on Earth was a protocell, and when we see, what it eventually managed to evolve into, we understand why science is so fascinated with protocells. If science can create an artificial protocell, we get a very basic ingredient for creating more advanced artificial life.


It seems counter-intuitive that in order to survive best as a species, not everything can live forever, but some cells in our bodies are fated to die, and a Mission Impossible-style auto-destruct program insures they do.

This elaborate cell death program, known as apoptosis, got a little more insight with a study on the evolution of caspase-8, a key cell death initiator molecule that was first identified in humans. By performing the most extensive evolutionary analysis of the Casp8 protein to date, 
Sakamaki et. al.,
write in Molecular Biology and Evolution


An interesting experiment published in Science placed baker's yeast ( Saccharomyces cerevisiae) in separate identical bioworlds. Then, at the same time, historical contingency events would happen, just like they have on earth - and only the fittest survived.

Evolution tells us that there are things besides natural selection going on - there are mutations and genetic drift. If we boiled up some primordial soup today, a few billion years from now the planet would be a lot different due to that randomness.

Or not.

Parasitic bacteria were the first cousins of mitochondria, the energy factories in our cells – and first acted as energy parasites in those cells before becoming beneficial, according to a University of Virginia study that used next-generation DNA sequencing technologies to decode the genomes of 18 bacteria that are close relatives of mitochondria.


What's not red and about the size of your thumb?

Tomatoes, before ancient scientists set out to make them patabale.  This genomic history of tomato breeding, based on sequencing of 360 varieties of the tomato plant, has vaulted beyond the first tomato genome sequence completed just two years ago. It will lend insight into science for people who believe genetic modification only began happening during the Clinton administration.

Analysis of the genome sequences of these 360 varieties and wild strains shows which regions of the genome were under selection during domestication and breeding. The study identified two independent sets of genes responsible for making the fruit of modern commercial tomatoes 100 times larger than their wild ancestors.



A female neriid fly (right) laying eggs, while her mate fights off a rival male. Angela Crean and Russell Bonduriansky. Credit: Author provided

By Angela Crean and Russell Bonduriansky

The evolution of new traits with novel functions has long been studied by evolutionary biology and a new study of the color markings of cichlid fish has shed some new light on it.

Swiss scientists writing in Nature Communications show what triggered these evolutionary innovations, namely: a mobile genetic element in the regulatory region of a color gene.