Death Star dinosaur aliens could rule galaxy

No way could a T-Rex fly a spaceship.

Their little arms couldn't reach the controls. What a ridiculous idea.

super-dinosaurs with iPads

If they have iPads, they will NOT be super-dinosaurs

Why not want to meet one?

Saying that you wouldn't want to meet a space wanderin' dino is so reptilist.

Just because they had big teeth and claws, it doesn't mean they haven't found peace and a desire to get on with other life forms.

"The dinosaurs are still with us, you just can't see them". You can. The sky if full of the blighters.

Relying on monsters from outer space to make your theory work:

So old school.

The "we're all left-handed" because of a single seeding event from a source that contains an even distribution requires something much like a limited gene pool to work. In order to have an ecosystem develop an almost exclusive distribution of one type from a starting source that has an even distribution requires a VERY small sample, as with a 50% distribution, every additional lichen/bacteria has a chance of being the wrong type. I have never been able to have more than a few coins turn up the same way in successive coin tosses. That's the nature of 50/50 odds.

In other words, the only way this theory would work is if one meteorite with less than a dozen bacterium/whatever started the whole thing. With a starting sample that small, it is about indistinguishable from having originated on its own from one happy left-handed start via lightning strike in a bowl of primordial soup.

If external seeding is a factor, and seeding would actually work so easily (one thing to plant, and entirely another to harvest...), and life in the universe has an equal chance of originating in either handedness, then seeded planets most likely would have a distribution of both types, a billion years being a short time for the living species we're able to comprehend, the universe being that big, and time in a geological/astronomic sense being an entirely different thing and all.

I'd think that a greater rarity of life-origination events and some functional benefit from leftedness makes a far more likely explanation. Seeding events where right-handed seeds are destroyed in transit/atmospheric entry would also fit the model, and I should wonder if seeding, handedness, and origination are not three different things -- seeding may be simple 'cross pollination' that drives a more rapid evolutionary cycle using compatible seeds, and the mechanism preferring handedness being as yet unexplained.

Its God's sinister plot to populate the universe, I tell ya!

Yeah, I know. IGMC.

May I be the first

To invite one of our remaining dino descendants for dinner.....

There is only one conclusion

Dinosaur ex machina

'dile Rockin'

I for one welcome our reptilian overlords.

Dinosaurs in flying saucers??

AWESOME!!! The only thing that would be cooler is Dinosaurs in X-Wings.....

Dinosaurs, but nice

The success of humans is dependent on the ability to cooperate. Sophisticated technology requires many hands and minds to work together with a reduced tendency to exploit, threaten, kill and/or eat their neighbors. Of course, it's an ongoing battle between exploiting your fellows as resources or partnering up to get the big stuff done because the many biological payoffs are with the exploit and cheat strategy.

In the end, it's the dinosaurs/newts/whatever that have evolved the cooperation genes along with brains that will be able to build spaceships. I doubt they'll think we are just a new type of breakfast.

DNA Damage

Life on earth might have been originated on Mars but cosmic radiation would destroy the DNA in the millions of years it would take for a rock to travel between solar systems.

Chirality and symmetry breaking

There's no mystery at the chemical level. L-amino acids form polymers (proteins) with other L-amino acids, and D-amino acids with other D-amino acids. These chains then fold up into spirals and sheets. Spontaneous bonding between L- and D- amino-acids is chemically unfavorable, because the molecules don't fit together properly.

So, if the first self-replicator was L-based, that would have fixed life (or pre-life) on the L-form, and soon the D-acids in the environment were reprocessed by it/them into small non-chiral molecules (i.e. used as food). Once the L-basis of life was established, it could never change. L-based life can't assemble things out of D-bases, but it can and does use them as fuel when they arise spontaneously.

The deep question is why was the first self-replicator to use amino-acid polymers based on the L-form? The answer may be that symmetry was broken at random. The pencil balanced on its point had to fall one way or the other. If so, and if we can ever find any other life to study, there's a 50% chance it'll be based on D-amino acids.

However, there's a much deeper broken symmetry that is itself chiral. The weak nuclear force. Because of this, the binding energy of L-amino acids is very slightly greater than that of D-amino acids. In a mixture formed by inorganic chemistry from achiral precursor molecules, there will be about 100 more L-molecules per mole than D (i.e. 1 part in 6.10^21). Was this enough to tip the balance? Is L-based life universal, thanks to a physical symmetry that broke almost immediately after the big bang itself? Can we ever know?

Back to trivia. In a few cases some living organisms manufacture an L- molecule and others the same molecule in D-form. What's the difference between lemon flavour and lime flavour? One is L-, the other is D-limonene! Why is 7-up "Limon" flavoured? Because in a chemistry lab, it's far easier to cook up a racemic (50/50) mixture, and that's what your fizzy water is flavoured with.

The real problem with the coverage of this piece

Was, I think, quite well highlighted in this response

http://www.wired.com/underwire/2012/04/alt-text-science-sensationalism/

It makes me wonder whether next month's issue will include a fairy cake recipe for those who want to build a Total Perspective Vortex in their backyard.