I’ve got two podcasts at Meet the Scientist to tell you about.
The first is a conversation with Nancy Moran, a Yale biologist who studies microbes that become essential to the survival of their hosts. In some cases, these symbionts lose just about all their DNA except for the genes that they use to be useful to their host–leading to the smallest genomes in nature.
The second is a conversation with Susan Golden of UCSD on the subject of time. We humans have a body clock, of course, but so do some bacteria. Why does a microbe need to know the time of day, when its lifespan can be far shorter? That would be like our body clock running a cycle of 1,000 years. Listen to find out.
August 19th, 2010 at 11:59 am
I was under the impression that most bacteria have life cycles measured in days or weeks. Is this wrong?
I understand why they may have a circadian clock even if they divide more frequently but what’s the real life cycle of most bacteria in the wild? Do most bacteria in the ocean really divide every few hours?
August 19th, 2010 at 12:14 pm
That’s a good point, Larry. I should say some bacteria *can* divide in as little as 20 minutes. What’s really amazing, as Golden points out, is that when the bacteria divide in two, the daughter cells inherit a clock set to precisely the right time, so that the clock essentially keeps ticking across the generations.
August 19th, 2010 at 12:53 pm
Do microbial life forms not divide indefinitely? A microbial life form, cloning itself indefinitely, is more immortal (regardless of the life span of an individual cell) compared to we (humans) who cannot, right? Surely anything alive will do better if it’s synchronized to ebb and flow going on around it.
[CZ: Bacteria get old and divide more slowly with time.]
August 20th, 2010 at 6:52 am
I would really thank you for this podcast, this is very interesting for me and sure for many people like be, on the on the other side of the world-EGYPT-, follow scientists on twitter , blogs and podcast also, soo great. This inspire us and make us stronger in our way through difficult challenges here.
August 20th, 2010 at 11:33 am
Off topic, but wanted to note that today is the 152nd anniversary of the Proceedings of the Lnnean Society of London’s publication of the joint Darwin – Wallace manscript announcing the discovery of Natural Selection as the primary mechnanism behind biological evolution.
August 20th, 2010 at 12:40 pm
Carl,
Looking forward to hearing your podcast with Nancy. Unless she’s keeping her lab in Tucson, her arrival at Yale is a major loss for Arizona. Didn’t know her well in graduate school there, but did read some of her work.
Regards,
John
August 26th, 2010 at 4:32 pm
Given that circadian clocks are set so finely to the Earth’s cycle, I wonder how humans an other earthly life forms can adapt to living on other planets. Will humans evolve by changing their circadian clocks, to match other planets’ cycles?