It has been a week of crazy writing–four pieces ranging from short to way too long. Hence little blogging. I apologize. I will reform. I will honor the blogger’s code. Monday. Continue reading “End of the Week: Radio news and web site restored”
Just a technical note, with shades of exasperation: After my web site got hacked earlier a couple months back, I changed ISP’s and spent a lot of time bringing it up to date. Now I’ve discovered that it’s not working again, because of some mysterious error. I’m getting help with it, but it may take a few days for everything to get back in place.
Originally published August 24, 2009. Copyright 2009 Carl Zimmer.
The Zimmer family takes over Bloggingheads. My brother Ben takes me on a journey through Word World. Check it out.
Originally published August 22, 2009. Copyright 2009 Carl Zimmer.
Science Magazine, August 20, 2009
We are, fundamentally, a fusion. As I wrote in my essay for Science on the origin of eukaryotes, there’s now a wealth of evidence that our cells evolved from the combination of two different microbes. The mitochondria that generate fuel for our cells started out as free-living bacteria. Today, they still retain traces of their origin in the bacterial DNA they carry, as well as their bacterial structure, including the membrane within a membrane that envelops them.
Scientists I spoke with as I worked on the essay agreed that this merging was a profound event in the history of life. No living eukaryote, whether animal, plant, fungus, or protozoan, has completely lost its mitochondria since that symbiotic milestone some 2 billion years ago. It wasn’t the only time that two species merged, however. Plants, for example, descend from algae that engulfed a species of photosynthesizing bacteria. Many protozoans have swallowed up photosynthetic partners as well.
Over at the Origins blog at Science, I follow up on my essay on the evolution of eukaryotes with a look at a new paper that suggests we are, ultimately, microbes within microbes within microbes. Check it out.
Originally published August 20, 2009. Copyright 2009 Carl Zimmer.