A few weeks ago I posted that 80,000,000 bacteria may be transferred when you make-out with someone for greater than 10 seconds. Perhaps it’s no surprise then that a bacterial signature may also be transferred during other intimate activities.
At one point in the study, the two people who lived together suddenly had more similarity in their pubic hair bacteria than they had before. It turned out that they’d had sex 18 hours before the sample collection. Ergo, the study authors suggest, a forensic investigator could use microbial shifts to help prove that two people had had intimate contact.
Data came from a study where researchers looked at head and pubic hair samples from seven individuals, finding that pubic hair microbes are more “individualized” than head hair microbes. And while the authors acknowledge this is very, very preliminary – the (distant) applications of microbial evidence are interesting to think about:
“The implication of this present study is that the transfer of bacteria between victim and offender, in rape cases, may provide a new way of linking the offender to the victim, in instances in which no human DNA is transferred.”
Read more about the study here.
The keywords of this post are ones I’m unwilling to Google Image search – so here’s an alpaca with silly hair. Relevant? No. Amusing and better than what would come up under a search for “pubic hair microbiome”? Yes.
Domesticated animals are the product of unnatural selection. To view some of the unnatural diversity in turkeys – check out Porter’s Rare Heritage Turkeys. They have the Sweetgrass, the Chocolate Slate, the White Holland, the Red Phoenix, and – my personal favorite – the Pencilled Palm (amongst many more varieties). They even have information on feather color genetics and what makes a (Heritage) turkey a (Heritage) turkey. Happy Turkey Day!
Is that a White Holland I see?
A new study released in the journal Microbiome (it’s open-access!) has concluded that “intimate kissing” that lasts at least 10 seconds can transfer 80,000,000 bacteria between the participants’ mouths. So many microbes sloshing around – it’s a little bit gross, a little bit cool, and 100% science.
NPR wrote a short piece about it here.
Figure 1 from Grice and Segre (2011), showing the distribution of viruses, bacteria, fungi and mites on our skin and where glands and hair follicles originate.
Our skin is an amazing organ – it keeps our guts in and intruders out. We have an average of 1.8 m2 and this area contains many distinct regions that vary in pH, temperature, moisture, exposure, etc. Your forearm is dry, your cheeks are oily and your elbow crease is considered “moist”. Hair follicles, pores, glands, nails – if we think of our bodies as planets, there are a lot of different habitats. And it turns out our habitats are home to many, many things.
Oh et al. (2014) analyzed 263 samples from 15 human beings at 18 habitats (anatomical skin sites). They were interested in the biogeography of skin – and how it varies between people and across habitats. Do all forearms look alike? Do all “dry” habitats have similar function? It was already known that there are large scale microbial diversity patterns in the skin microbiome. For example, oily sites contain relatively low taxonomic diversity, perhaps because these sites are most selective when it comes to who is able to live there. At the other end of the diversity spectrum are dry sites, which tend to have high diversity.
Well, the title pretty much says it all – two recent studies shed some light on the biological origin of the wiener.
Today, two teams of researchers report having solved one part of this mystery, pinpointing how the organ gets its start in snake, lizard, mouse, and chick embryos. Now that they understand the penis’s origin, researchers can track its development in more detail to understand what drives it to follow a different path in females and become a clitoris. The finding doesn’t just answer a biological conundrum; it could also help millions of people born with genital malformations.
Read the research highlight in full here.
Crazy cool picture of a snake embryo, complete with tiny penis buds instead of legs.
In honor of Halloween – all you ever wanted to know about the inner workings of a tarantula. That is, of course, if you’re not too scared…