Endless and Beautiful

Biology: evolution, development, genetics, molecular.

[exploringthebranches-blog]

Why it's time to lay the selfish gene to rest – David Dobbs – Aeon

For decades, the selfish gene metaphor let us view evolution with new clarity. Is it now blinding us?

Regulatory networks challenge the selfish-gene model first because they include DNA elements not conventionally defined as genes. More important, some researchers believe these networks challenge the selfish-gene model because they often seem to behave not like selfish entities balancing their separate agendas, in selfish-gene style, but like managerial teams regulating the behaviour of individual genes for the interest of the organism.

[smilesandvials]

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[exploringthebranches-blog]

Sex redefined

The idea of two sexes is simplistic. Biologists now think there is a wider spectrum than that.

[currentsinbiology]

Sex differences and vulnerability: how the male-female divide affects health

Carole Jahme interviews controversial evolutionary psychologist Professor David Geary on the implications of sex differences and hard-wired gender disparity. Video: Oscar Dunbar

[earthlynation-blog]

Dyeing Dart Frog

[exploringthebranches-blog]

A collaborative effort to create provides information about biodiversity, the characteristics of different groups of organisms, and their evolutionary history. 

[exploringthebranches-blog]

Simply complex: The origin of our body axes

One fundamental question in biology is what constitutes the basic type of the animal body plan and how did all the more complex forms, including that of humans, evolve from it. At the simplest level, this body plan can be described by the three axes. These three axes -- the familiar X, Y and Z axes from geometry -- are the anterior-posterior axis, which determines the position of the mouth in front and the anus at the rear, the dorsal-ventral axis, which in vertebrates separates the front of the body from the back, and the left-right axis, which creates a mirror-like symmetry of our extremities and left-right asymmetry of the organs.

[amolecularmatter-blog]

Ancient Viral DNA in the Human Genome

Traces of ancient viruses, which infected our ancestors millions of years ago, are more widespread throughout our modern-day genomes than was previously thought.

The new research sheds light on the origins of a large proportion of our genetic material, much of which is still not understood. Only about 1.5% of human genes code for a useful protein product, that we’ve discovered; half of the rest is labeled “junk DNA” - although new research indicates it has a variety of purposes - while the other half was introduced by viruses or parasites, like the ancient ones studied here.

The senior author on the study (published in the Proceedings of National Academy of Sciences), Dr. Robert Belshaw from Oxford University’s Zoology Department, said: “This is the story of an epidemic within every animal’s genome, a story which has been going on for 100 million years and which continues today.

"Much of the dark matter in our genome plays by its own rules, in the same way as an epidemic of an infectious disease but operating over millions of years.

Learning the rules of this ancient game will help us understand their role in health and disease.”

Not only do these viruses exist within our genomes, but some of are even helpful, Dr. Belshaw insists. Protein syncytin, for example - derived from a virus - helps develop the human placenta.

The study believes that unlocking the secrets of these viruses is essential to understanding the full complexity of the human genome.

Image: SEM image of Influenza A virus.

[exploringthebranches-blog]

The Last Great Ape (2007) -- NOVA

One of our closest living relatives is the Bonobo. Unlike chimps, known for their violent behavior, Bonobos are far more peaceful and resolve conflict in an unusual way: by having sex. Much like humans Bonobos have sex not just to procreate but also for pleasure and politics. Discovery of these gentle apes has fascinated scientists and led them to question our origins and the roots of human nature.

[currentsinbiology]

Naked Ambition (Scientific American)

Native to the Horn of Africa, this small rodent (Heterocephalus glaber) is neither a mole nor a rat; it is actually more closely related to porcupines and guinea pigs. The animal’s pale-pink, wrinkled skin is nearly hairless, the better to slip through those narrow burrows. But there is yet another more compelling fact: in all the thousands of naked mole rats that have lived and died in research labs and zoos over the past several decades, not a single instance of spontaneous cancer has been recorded1.

Researchers have found it tough to induce cancer in naked mole rats. Working in culture, they have infected cells from the creatures with a genetically engineered virus that contains a pair of oncogenes, or cancer-promoting genes, that reliably turns mouse cells malignant2,3. “This common oncogenic cocktail had no effect on the naked-mole-rat cells,” says Rochelle Buffenstein, a physiologist at the University of Texas, San Antonio, and a pioneer of naked-mole-rat research. “They did not become tumorigenic, they didn’t rapidly proliferate, they didn’t invade tissues.”

[exploringthebranches-blog]

Eric and Jim go over the basics of doing a frozen section. Crew: Eric Miller and Jim Geimer (presentation), Mike Nguyen (filming), Jean Oak (editing)

Tutorial and notes on embedding tissue and sectioning using a cryomicrotome. Note that in this video, they do not use an anti-rolling glass to secure their section.