This post is a continuation of speaker summaries and my review of SkeptiCamp Kentucky 2012.
Space elevators – Bob Malcolm
Bob Malcom’s talk was about space elevators–how they would work in principle and how they could be used to make space exploration cheaper and more efficient. Space elevators work by using a line suspended by a platform in geostationary orbit.
Bob then discussed how heavy elements are created in supernova explosion. Most of those elements in the earth are probably in the center of the earth, but some of these elements on the surface came from meteorites. One argument for space elevators is that they can be used to help mine asteroids. NASA, Google and Japan have plans to mine asteroids. Even now, calls have been sent out by those who are planning such trips to find people who are willing to spend the rest of their lives of Mars.
Parasites – Melody Ward
Melody is fascinated with parasites, not just for the gross factor, but for their amazing and crazy adaptations to their hosts.
Several examples are given, such as the pain killer and anticoagulants in leeches used to prevent detection, disinfect the blood (to keep the food good for itself, but it also helps prevent infection), and prevent the blood from clotting.
The tapeworm has different life cycles for living in vector and in host.
Sacculina is a barnacle that paritisitizes a crab. It uses the crab female to protect and groom it’s eggs, and then controls the male crab to make it act like a female to build and groom an egg sack.
Cymothoa exigua actual replaces a body part of its host. It kills the tongue of the host by sucking the blood out of it until it falls off and then the parasite becomes the tongue.
Next are nest parasites, such as the brown-headed cowbird. They lay their heads in another bird’s nest. The impostor egg is easy to point out because it is black speckled. However the host bird still cares for it with the others. This is an important adaptive behavior for the species because cowbirds are adapted to follow cattle herds and they cannot take their nests with them.
Coocoo birds, another nest parasite, will actually push the other eggs out of the nest before they hatch. Also will push out the other chicks if they are small.
Leafcutter ants and the Phorid fly. Fly lays it’s egg inside the ant. The flies have been used for fire and control. Leafcutter ants use guards to protect against the flies.
Parasites are especially interesting from an evolutionary perspective when you see the ways in which they are constantly needing to adapt to their hosts, as their hosts adapt to fight them off. The Red queen hypothesis states that parasites and hosts have to continue to adapt (keep running) just to stay at an equilibrium with each other.
Parasites have also played an important role in our own evolution. Sickle cell anemia, for example, is a defense against malaria parasite. Chloroplasts in plant cells and mitochondria in animal cells were once parasitic bacteria that developed a symbiotic relationship with the cells of other organisms. (This is why mitochondria have their own DNA.) Retroviruses, which use parasitic genes which insert themselves into the host’s DNA, are inherited though the family line can can be used to trace a species’ ancestry. Autoimmune diseases which affect many of us such as allergies and arthritis evolved as a response to parasites.
One of the most interesting points made in Melody’s presentation is the way that parasites can be involved in the development of social behavior. There is a monkey that lives in an area where it could be a parasite called a screwworm in any opening in it’s skin. This prevents the monkeys from fighting since they don’t want to get scratches due to the risk of screworms, and leads to a much more peaceful environment than might have otherwise developed in the monkey colonies.
Review and Conclusion
There were more speakers after this, however, I was not feeling well on that day and opted to leave a bit early, I have only provided summaries of the speakers that got a chance to hear. The time that I spent there was a good time, I learned a lot, and I am looking forward to next year.