The second episode of CreatureCast is now online! Created by evolutionary biologist Casey Dunn and his students at Brown University, CreatureCast is a terrific Web video series about unusual animals and evolution. Sophia Tintori, a student whose research focuses on marine invertebrates called Siphonophorae, put together the first episode, about squid iridescence, and this one too. Professor Dunn says:
(Tintori) spoke with Cassandra Extavour about the evolution and development of multicellularity, and how the ability to contribute to the next generation of organisms is usually restricted to a small population of special cells. This topic is near and dear to the research we do in our lab. Among other things, we look at the division of labor, including the ability to reproduce, in siphonophores.CreatureCast Episode 2
Previously:
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Contagious Cancer
"Cancer differs ... from heart disease and cirrhosis and the other lethal forms of physiological breakdown; uncontrolled cell reproduction, not organ dilapidation, is the problem.
"Such uncontrolled reproduction begins when a single cell accumulates enough mutations to activate certain growth-promoting genes (scientists call them oncogenes) and to inactivate certain protections (tumor suppressor genes) that are built into the genetic program of every animal and plant. The cell ignores instructions to limit its self-replication, and soon it becomes many cells, all of them similarly demented, all bent on self-replication, all heedless of duty and proportion and the larger weal of the organism. That first cell is (almost always) a cell of the victim’s own body. So cancer is reinvented from scratch on a case-by-case basis, and this individuation, this personalization, may be one of the reasons that it seems so frightening and solitary. But what makes it even more solitary for its victims is the idea, secretly comforting to others, that cancer is never contagious. That idea is axiomatic, at least in the popular consciousness. Cancer is not an infectious disease. And the axiom is (usually) correct. But there are exceptions. Those exceptions point toward a broader reality that scientists have begun to explore: Cancers, like species, evolve. And one way they can evolve is toward the capacity to be transmitted between individuals.
Source: Harper's, via BoingBoing.
Cancer cells evolve in tumors
"Cancer cells in a tumor evolve due to natural selection. They compete fiercely for reproductive space inside the tumor, changing strategies to beat out other cancer cells and to triumph over chemotherapy."
- Science News, via BoingBoing
Love Sophia's visual explanations of complex natural events!! Makes me want more. Thanks for posting (and creating)them!