Evolution may serve as danger to living organisms

10/15/08 - Judith Swift will remember Tuesday, Oct. 14, 2008 for the rest of her life. And so will the audience at the Fall 2008 Honors Colloquium.Charles Darwin's theory of evolution has one flaw - that it can happen very quickly, as proven by diseases - and it will be required of about 25 percent of the world's mammal population to survive, said Dr. Stephen Palumbi, a professor at Stanford University.

At last night's Honors Colloquium, Palumbi said organisms with shorter generations and large populations will be the most likely to survive climate change, and organisms with large generations and smaller populations will be most prone to extinction.

"There is an alternative for species who can't [survive on their own], and that's us," Palumbi said. "For those species in particular, it is time now to find habitats for them to survive for the next 50 or 60 years."

After the speech, Palumbi said even human life will be subject to climate change, but its demographic will help prevent extinction.

"We have a prett†y big population size, we're spread in all kinds of environments, and the 6 billion of us, we're a lot less on the chopping block than anyone else in the mammalian world," Palumbi said.

Palumbi began his lecture with a list of antibiotics, beginning with penicillin. Penicillin, Palumbi said, was commercially available in 1943, and the first resistance to the drug was reported in 1947. A new antibiotic was invented, which created "evolutionary pressure" on the disease, creating resistance, and eventually the need for an even stronger drug.

In 2000, a drug called linezolid was invented, which was a stronger drug acting as a sequel to Penicillin, Palumbi said. It was available in 2004, and two years later, the first resistance to the drug was reported. Palumbi called the cycle an "arms race," and now there is a race to develop a new drug of last resort.

"You do not want to be on the drug of last resort," Palumbi said. "Why? Because where do you go from there? This was a set of developments we can see in the pages of every medical journal."

The diseases malaria and tuberculosis were in a similar situation. Drug-resistant case reports of malaria are on the rise on the coasts of central Africa and Southeast Asia. As a treatment becomes more successful, Palumbi said, its use becomes more widespread, and so does the resistance to the treatment.

And the speediness of evolution has been suggested by behaviors of even larger organisms. Insects have also become more resistant to insecticides, to the point where Palumbi said it is "impossible" to treat some insects with pesticides alone.

Some salmon have evolved into a torpedo-like shape to fit through the holes of nets of hunters, Palumbi said, and those salmon are, "eaten mostly in restaurants where they assure you it's wildly caught salmon served to you at those prices."

About 80 to 90 percent of adult fish that swim up-stream are caught, Palumbi said.

Animal behavior has also changed, as a result of human-related factors. Palumbi said whale hunting in southern California has driven the humpback whale to Hawaii.

The rapid evolution found in salmon and diseases may be needed for species of coral and other mammals.

Palumbi said warming trends during the last 10,000 years show the Earth warming about .07 degrees Celsius per century, and warming is predicted to be about .7 degrees Celsius this current century, or about 10 times faster.

"What it tells us is if organisms are going to adapt to their environment, they're going to have to evolve about 10 times faster, and that may well overstep," their abilities, Palumbi said.

Palumbi said coral is in danger because it contains a certain chemical, called symbiont, which allows it to photosynthesize. In warmer water, coral releases all its symbionts and dies.

But Palumbi said some coral in Hawaii is able to survive at water temperatures; the exact reason is unknown, but it could be a genetic change.

Birds in England have also demonstrated migratorial deviations as a result of climate change.

Humans, Palumbi said, also demonstrate change, but on a genetic level. He cited a genetic for lactose tolerance, which is more pronounced in Northern Europeans.

"A lot of the change that's happening is behavior based, but we're also seeing some hard-wire change," Palumbi said.

Some of that hard-wire change will be visible in Rhode Island. Palumbi said sea levels may rise, and organisms that live in marshes will simply move to where the shallows are, but housing developments or highways may inhibit them.

Palumbi finished the lecture by saying that evolution happens faster than Charles Darwin thought, and global climate change will demand evolutionary change, rapid adjustment or extinction.

"If we don't want extinction to happen, we have to do something about it, and we have to do something about it now," Palumbi said.