So, I heard about this a day or two ago and the author was holding off on calling it a new species, but I just found new releases on the matter. Here’s the deal – a finger bone, now determined to be from a female and found in Siberia, was found a while back and contained mitochondrial DNA. It was dated to be from a girl who lived some 30-48 thousand years ago.
So we found a finger, so what? Well, even though I find it kind of amazing that it still had detectable genetic information within it, it has a bigger impact than that. Now that it’s being looked at more closely, scientists are calling her a member of a new species of humans. By what method of speciation has this been determined? Well, her mitochondrial DNA does not follow the same pattern of evolution comparable to the Homo erectus that spawned our ancestors. This finger, or rather the ancient girl once attached to it, seems to have branched off way back when and developed differently. It seems to still be not 100% definitive, and I’m guessing that naming it is pending further evidence as well. Interesting, and I look forward to learning more about this new species in the near future.
Bacteria! We all know that when resources get scarce, things go a little wonky. Paenibacillus dendritiformis gets a little weird when resources are scarce, too, but in a strange way. When on a nutrient-low plate, two colonies of P. dendritiformis grow away from each other, with a gap between the two fringed with dead cells. It turns out, in the media between the two there was a protein deemed “sibling lethal factor.” The scientists isolated the gene producing it and attempted to recreate it, but came out with a different, harmless version. So, being wickedly clever, they found that P. dendritiformis also creates subtilisin to modify the sibling lethal factor, turning it into a killer knife that tears open competing cells. Creepy…but cool. Learn more about the experiment in the links at the bottom of this post. :)
Now zoom over to Texas, where monarch butterflies are getting scarce. The epic butterflies typically migrate from Mexico to Canada, and around this time Texans start seeing them pretty frequently. This year, however, Texans have only seen them a reported total of 12 times, contrasting last year's 70 at this time of year. Issues contributing include cold weather, wet weather, and logging around their Mexican habitats leading to mudslides (that are having a pretty big effect on people, too!). To help, Texans have been asked to plant butterfly gardens, with nectar for the travelers. Apparently, they rely pretty heavily on a good breakfast. Good luck, little guys!
Last for today, some really interesting research has been turned out from the National Institute of Aging on embryonic stem cells. Until now, it’s been sort of a mystery how stem cells seem eternal, but normal cells have a lifespan. Telomeres are the sections at the ends of genetic material – they become shorter each time a cell replicates. Essentially, your typical cells have a predestined lifespan, if nothing kills them prematurely. Embryonic stem cells, however, at least in mice, can just keep chugging. The method is the interesting part.
When an ES cell deems it appropriate, it switches on coding a gene called Zscan4. This basically rebuilds those telomeres. We used to think they had a over-time recharging health bar…but they don’t. They have health potions! :) Fingers are crossed that this finding will be replicated in human ES cells, too.
That’s it for me today. See you Sunday!
- Miss Mouse
References and Links:
Finger DNA
Sibling Lethal Factor
Monarch Butterflies
Mouse Embryonic Stem Cells
