Don’t let go of me (Grip my hips and move me)
Why do fingers get wrinkly in the water? […]
A hypothesis has been proposed which suggests that the wrinkling might be an evolutionary adaptation to make the handling of objects underwater easier. Wrinkling creates a kind of drainage path for water and so enhances the grip on an object (this is called a ‘rain tread’ hypothesis). In order to test if this hypothesis is true Kareklas et al. have recruited volunteers and tested their ability to transfer wet objects when the fingers are wrinkled and not. […]
20 participants had to transfer glass marbles from one container to another in two different conditions (1) take the marble from a container with water pass it through a small hole and put into an empty container and (2) take the marble from a container without water pass it through a small hole and put into an empty container. […]
When the marble ball was dry there was no difference between the transfer time with wrinkly and smooth fingers. However, when the marble was wet then on average it took 12% less time to transfer the object with wrinkly fingers. Therefore, the study concluded that the wrinkling of fingers improves the handling of wet objects (which supports the rain tread hypothesis). Why are our fingers not always wrinkled then? In paper’s discussion Kareklas et al. suggest that there potentially are some fitness trade-offs to the wrinkly fingers. Maybe wrinkled fingers are less sensitive to pain, pressure, heat etc. and are therefore damaged easier, which would explain why it is not good to always have those wrinkles.
{ The Question Gene | Continue reading }
The work done in this room lies at the heart of a department that handles some of the UK’s most cutting-edge research on forensics and anatomy. […]
The hand is Meadows’ area of focus. Variations in scars, skin pigmentation, the smallest nooks and crannies of the fingernail and, most importantly, superficial vein patterns: all of these can build a body of evidence and allow the police to identify an offender in an incriminating photograph. “The back of the hand is part of the anatomy that an offender is quite happy to have in an image, whereas they wouldn’t necessarily want their face captured,” Meadows says. In 2009, Cahid’s work was instrumental in the Neil Strachan case, part of Scotland’s biggest paedophile ring. His unusually distorted lunula (the white half moon at the bottom of a nail) helped identify and convict him.
Meadows and her colleagues have built up the UK’s only database of the hand’s vein patterns, with around 800 samples. Of the 40 or so cases they have worked on, their data have resulted in over 80 per cent of suspects changing their plea.
