Good question Daniel from Gizmodo!
Cavefish can ‘keep time’ via the circadian clock but whether they perceive it and what keeping time means when you’re underground is a mystery. Other researchers give more information in Daniel’s article:
Rhythms in red blood cells and the ever-present casein kinase
My latest research was published in Journal of Biological Rhythms this week. It is open access here: Casein Kinase 1 Underlies Temperature Compensation of Circadian Rhythms in Human Red Blood Cells.
Continue reading “Rhythms in red blood cells and the ever-present casein kinase”
Sleep during the early stages of urbanisation
This week, I publised an article entitled Comparison between an African town and a neighbouring village shows delayed, but not decreased, sleep during the early stages of urbanisation in the journal Scientific Reports. The article is Open Access, which means it is freely available for all to read.
I hope the research has contributed to the discussion on artificial light, urban lifestyles and sleep and that other researchers find it useful. But in this post, I want to reflect on the background to the story – how the research came about and what happened when it got some publicity. Continue reading “Sleep during the early stages of urbanisation”
Jet lag – the disadvantage of having a clock in the modern world
Air travel challenges our bodies in a way that has never before been encountered in our evolutionary history. It allows us to move rapidly across multiple timezones, quicker than we could have ever moved by foot or animal. Unfortunately, our bodies are unable to adjust quickly enough. We are constrained by our circadian clocks, the things that give our bodies a sense of internal time, which have evolved to coordinate our physiology to the rhythmic and predictable changes in the external environment (as well as other roles) like day and night. The clock keeps its original time when you move timezones like a watch before you’ve reset it. It’s resistant to rapid change, giving us jet lag. However, unlike a watch, the body clock can gradually reset itself over a period of days so that we become tuned to a new local time. Despite this inbuilt mechanism, in an era of global travel it is often too slow.
Is it possible to speed up the resetting process? Can we travel the world without jetlag?
Maybe.
Continue reading “Jet lag – the disadvantage of having a clock in the modern world”
The Mount Mulanje Pygmy Chameleon
Christine Cambrook | CC BY-NC-SA 4.0
By far the rarest animal that I have encountered during my time in Mozambique has been the Mount Mulanje Pygmy Chameleon, Rhampholeon platyceps. A stunning little creature, it is endemic to the Mulanje massif, only being found in the southern and eastern-facing mid and high altitude evergreen forest of the massif. This includes the Ruo Gorge, where we came across the little guy (or possibly girl) above. Unfortunately its forest habitat remains only in fragmented patches and, due to its restricted range and the high threat of deforestation, it is declared Endangered by the IUCN Red List. We were lucky that this individual was crossing the path in front of us.
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Do we have the right to eradicate species?
While living in Mozambique I have seen first-hand the tremendous suffering caused by mosquitoes and the diseases that they transmit, especially in children. Friends have lost children to malaria and, in this rainy season especially, neighbours are frequently coming down with the disease. According to the Gates Foundation, malaria, transmitted by the mosquito Anopheles gambiae, caused 627,000 deaths in 2012. It’s a scourge to the human race. When you add in dengue and chikungunya, two other mosquito-borne diseases, and the strong (but not yet conclusive) association between the zika virus and microcephaly, mosquitoes become the animal incarnation of the Grim Reaper.
Continue reading “Do we have the right to eradicate species?”
What can a blind cavefish tell us about circadian clocks?
Circadian clocks and a revolving planet go hand-in-hand. But why so many plants and animals have a circadian clock from an evolutionary perspective is relatively unknown. One way to find out is to study animals that live in non-rhythmic environments. And at the end of 2013, my team published a study on exactly that: the circadian clock of the Mexican blind cavefish, Astyanax mexicanus, from data collected in the laboratory and in the fishes’ natural habitat. We showed that these cavefish fish shows wonderful daily patterns of behaviour and gene expression, confirming that it has a functional circadian clock.
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Presentiment – circadian clocks giving plants and animals a sense of time
Presentiment is that long shadow on the lawn
Indicative that suns go down;
The notice to the startled grass
That darkness is about to pass.
Sometimes you find in literature beautiful expressions of technical terms that are otherwise dry and stuffy. Presentiment, by Emily Dickinson, is one of those beautiful expressions. Why did she decide to write a few words about twilight, and at the same time so succinctly summarise one of the key features of the circadian clock? Apparently Dickinson spent much of her adult life withdrawn from the world and, in doing so, she was probably in a position to watch and notice the hidden-in-plain-sight details of the world, such as how the length of shadows allow you to approximate the time of day and how grass may tell time without watches.
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Solstice
In the northern hemisphere, today is the Winter Solstice, the shortest day of the year.
The Solstice normally falls on either the 21st or the 22nd, the date changing based on the exact position of the north pole in relation to the sun. This is the same reason why we have leap years – our calendar year doesn’t match up with the solar year, and so we have to add a day on every four years in order to recalibrate our calendars with our position in space. This year, 2015, the point at which the north pole is furthest from the sun falls on the 22nd December. Continue reading “Solstice”
Parasitoid wasps and GM butterflies
Foreign pieces of DNA are found in the genomes of many animals – these ‘Genomic parasites‘ are pure, genome hopping pieces of DNA code which embed their lifecycle within the DNA in our own cells. You could call this genomic parasitisation a form of genetic modification, just as scientists in labs the world over use simple molecular biology techniques to insert useful genes into genomes to better understand biological processes. However, most of the time, genomic parasites like transposons have no function in their hosts and simply hitch along for the ride, reproducing as the host reproduces. This doesn’t fit our usual understanding of the meaning of genetic modification, which involves humans and active manipulation of the genome, in most cases to improve it.
However, a recent piece of research shows another form of natural genetic modification which also doesn’t involve humans – and this form does affect the life of the host and can confer some advantage. Continue reading “Parasitoid wasps and GM butterflies”
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