Now Playing Tracks

Education on the value of free speech and the other freedoms reserved by the Bill of Rights, about what happens when you don’t have them, and about how to exercise and protect them, should be an essential prerequisite for being an American citizen — or indeed a citizen of any nation, the more so to the degree that such rights remain unprotected. If we can’t think for ourselves, if we’re unwilling to question authority, then we’re just putty in the hands of those in power. But if the citizens are educated and form their own opinions, then those in power work for us. In every country, we should be teaching our children the scientific method and the reasons for a Bill of Rights. With it comes a certain decency, humility and community spirit. In the demon-haunted world that we inhabit by virtue of being human, this may be all that stands between us and the enveloping darkness.
Carl Sagan — Ch.21 Real Patriots Ask Questions, The Demon-Haunted World : Science as a Candle in the Dark (1995)






Occupy Pragmatism

Download the poster pack


Spot on!

Thinking about not voting this year? It’s the Supreme Court, stupid.

Reblogging for massive importance

Sames thing goes for: Equal rights, fair pay, healthcare, women’s health and the environment etc etc… Just imagine the sate of the SCOTUS if today’s republicans get to appoint even ONE judge, let alone 3.


Viral Conception

How the origin of mammals could be written in our genome … by viruses.

Every human being starts the same way, with a sperm and egg becoming one, 23 chromosomes from each parent contributing the genetic instructions that will one day make, well … you. But the genes, the actual DNA that writes for proteins, make up only about one one-hundredth of all the DNA in those 46 chromosomes.

A full 8% of the DNA in your genome, though, are the remains of ancient viruses. A certain type of virus called a “retrovirus” is capable of inserting its genome into its host, literally writing itself into your DNA. This is the family that HIV belongs to. If a retrovirus infects an egg and inserts its genome, it can get passed down to the next generation. We are full of these remnants, as inactive but still recognizable fossils of past infections.

Dr. Samuel Pfaff and his team were trying to come up with a list of genes that were turned on in a developing mouse embryo, just after sperm and egg had come together. In its earliest stages, an embryo’s cells can become any tissue (one of the ideas behind stem cell therapies). What genes make this possible?

It turns out that for over 100 genes, the switches (called “promoters”) that turned them on came from a very unlikely place: viruses. WHAT?! We know that these genes must be activated in order for an embryo to correctly develop, but the switches that control them come from ancient viral infections! The genes themselves? Purely mouse. 

What an odd paradox of evolution!! We need these genes on at a very precise moment, and off a short while after that. If any of it goes wrong, no baby mouse. So evolution selects these viral sequences to be the control mechanism. Could an ancient infection have been the key to the very existence of mammals?

Carl Zimmer has more at The Loom.

We make Tumblr themes