Archive for the ‘Chelicerata’ Category

Information is important. With information each of us as individuals, and our society as a whole, can learn about the world. With information, we can all make decisions that make sense. With information, we can all discuss ideas.

Without information none of that is possible. Without information, we are, at best, at the mercy of our current, limited knowledge, and our base instincts. Without information we are, at worst, at the mercy of the limited knowledge and instincts of someone else.

This is why the gag order, and insistence that all reports and data be pre-screened before release to the public, issued by the President to the EPA are so concerning to me, and I think should be so concerning everyone else. This is exactly the kind of action that limits access to, and spread of, information. It will only hamper all of our abilities to operate as rational, critically thinking individuals. It is the kind of action that is put in place to control what we, as citizens, know and when we know it. This is censorship and it has no place in science or a free society.



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Western Fence Lizard (Sceloporus occidentalis). Photo courtesy of Jocelyn Knight.

There is a small lizard that lives all across the western USA that has a superpower! The lizard is the Western Fence Lizard (Sceloporus occidentalis) and the superpower is that it can kill Lyme Disease. This is not a new story, by any means, but it is a great one. It is also a reminder that there are amazing things to discover in our back yards, and that we gain amazing benefits from unlikely parts of the natural world.

So, the story is this. A person in Connecticut is about 100 times more likely to get Lyme Disease than a person in California. Why is this true? This was a puzzle for scientists and public health specialists.


Female Black-legged Deer Tick (Ixodes scapularis). Photo courtesy of Innovative Pest Management.

Many possible ideas have been examined. Is it because there are more ticks in Connecticut? No, there are lots of ticks in both states. Well, only certain species of tick can carry Lyme Disease, so maybe those species occur in Connecticut but not California. No, the species of tick, members of the genus Ixodes, occur in both states. Ok, where do the ticks get Lyme Disease from, maybe the reservoir for the disease is only found on the east coast, but not the west. Nope, the disease is commonly found in many species of mammal, deer particularly, and these animals are found all across North America. Well, maybe people in the two states are not getting bitten at the same rates for some reason. No, the numbers of bits per 100,000 individuals is about the same. But, for some reason, when a person is bitten by a tick in California they very rarely get Lyme Disease.

It turns out that this is because most ticks in California (and I am talking about the members of the genus Ixodes that can carry Lyme Disease, here) don’t actually carry Lyme Disease very often. They can, but they generally don’t.

An entomologist at the University of California, Berkeley (Robert Lane, Ph.D.) figured out why they don’t back in the late 1990s. It turns out that one of the common hosts of ticks in the western USA are Western Fence Lizards and Western Fence Lizard blood contains a protein that kills the Lyme Disease causing organism (a bacteria called Borrelia). In lab tests, Borrelia bacteria that was placed in mouse blood would survived for about three days, but Borrelia bacteria that was place in Western Fence Lizard blood died in one hour! (On a bit of a side note, when I was a kid my family and I actually did some field collecting for this project. When we went hiking in the east bay hills, we would save the ticks we found on ourselves or the dog and take them in to UCB.)

So what happens is that any time a tick bites a Western Fence Lizard, the blood that the tick drinks kills off all the Borrelia in its system. If that tick then goes on to bite you, it has no Borrelia to pass on to you and you do not get Lyme Disease. Pretty cool, right? One of the big, unanswered questions is what protein, exactly, in Western Fence Lizard blood is so lethal to Borrelia?

So, next time you see a Western Fence Lizard say thanks for the Lyme Disease protection. The next time you find a tick on you, don’t panic because it probably has been drinking blood from a Western Fence Lizard and so has no Lyme Disease to give you, unless you are back east in which case you should probably watch for possible Lyme Disease symptoms.

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