Daily Archives: September 12, 2008

Room for Improvement

Being human, we are always trying to find a way to improve our condition. We’re never satisfied with the status quo.

One very important metric for improvement is life span.

lifespan graph.gif

I found the above graph in a paper by Marvin Minsky. It shows that only about 20% of people lived to see age 45 in ancient Rome. By 1900, 20% of people lived to just above age 70. By 1960 20% made it to age 85.

Check out that last “all diseases cured” curve. If we cure all diseases (all diseases, that is, except aging itself) 20% will make it to 95. So if you’re part of that lucky 1 in 5, curing all disease would give you only 10 years more than you would have had in 1960. And the maximum life span hasn’t increased at all.

When Why Dinosaurs Ruled the Earth

What allowed dinosaurs to be the dominant form of life on earth for all those millions of years? Would you believe they just got lucky?

The closest competitors to the dinosaurs during the Triassic period (about 251 to 199 million years ago) were the crurotarsans, the ancestors of today’s crocodiles.

Both dinosaurs and crurotarsans evolved and filled some of the same ecological niches after a massive extinction event at the end of the Permian period some 250 million years ago. Both groups also survived a later extinction event about 228 million years ago.

The researchers found no difference in the rates of evolution of the two groups. If dinosaurs were out-competing the crurotarsans, they should have been evolving faster.

Crurotarsans also had a much higher disparity – in other words, they were exploring a wider range of body types, diets and lifestyles. Again, this should have given them a leg up on the dinosaurs.

So why did the dinosaurs survive that second mass extinction event, while the crurotarsans (except for a few lineages of crocodiles) disappeared?

“We don’t know the answer to that,” Brusatte said, “but we suspect that it was nothing more than luck, plain and simple.”

Personally, I find the “luck” explanation less than satisfying. There must have been a real difference between the two groups that allowed one to survive the extinction event. You can say that the dinosaurs were “lucky” to have that trait — or set of traits — or you can describe those traits as an evolutionary advantage against at least that particular kind of extinction event.

I guess unless one argues that the dinosaurs deliberately developed a resistance to that kind of event — and I’m certainly not saying that — the two arguments mean the same thing. Looks like some pretty important things really do come down to luck.

When Why Dinosaurs Ruled the Earth

What allowed dinosaurs to be the dominant form of life on earth for all those millions of years? Would you believe they just got lucky?

The closest competitors to the dinosaurs during the Triassic period (about 251 to 199 million years ago) were the crurotarsans, the ancestors of today’s crocodiles.

Both dinosaurs and crurotarsans evolved and filled some of the same ecological niches after a massive extinction event at the end of the Permian period some 250 million years ago. Both groups also survived a later extinction event about 228 million years ago.

The researchers found no difference in the rates of evolution of the two groups. If dinosaurs were out-competing the crurotarsans, they should have been evolving faster.

Crurotarsans also had a much higher disparity – in other words, they were exploring a wider range of body types, diets and lifestyles. Again, this should have given them a leg up on the dinosaurs.

So why did the dinosaurs survive that second mass extinction event, while the crurotarsans (except for a few lineages of crocodiles) disappeared?

“We don’t know the answer to that,” Brusatte said, “but we suspect that it was nothing more than luck, plain and simple.”

Personally, I find the “luck” explanation less than satisfying. There must have been a real difference between the two groups that allowed one to survive the extinction event. You can say that the dinosaurs were “lucky” to have that trait — or set of traits — or you can describe those traits as an evolutionary advantage against at least that particular kind of extinction event.

I guess unless one argues that the dinosaurs deliberately developed a resistance to that kind of event — and I’m certainly not saying that — the two arguments mean the same thing. Looks like some pretty important things really do come down to luck.

Kathy on the LHC

Speculist contributor Kathy Hanson (who also blogs at Beyond Words) has been involved in the long, slow process of selling out to the mainstream media over the past few years. Stephen and I totally approve of this, of course, as we are constantly trying to pimp out FastForward Radio to some big media outlet — so far with less success than Kathy has had.

Anyhow, her she is with some thoughts on the Large Hadron Collider.

A shot was heard around the world on Wednesday. But no bullets or guns were used. The projectile was a beam of photons fired through the Large Hadron Collider’s 17-mile ring of tunnel. And the only noise involved was the cheering of elated scientists, including two graduate students from Iowa State University, celebrating how well the complicated systems worked for the first firing of the most powerful particle accelerator ever built.

Kathy reports that her current gig has her focusing a lot on hard science stories, so we’re looking forward to more of these.