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.
We’re all aware of our natural body clock pattern: some people are early birds, some people are night owls, a phenomenon known as your chronotype. You can override this with alarm clocks and coffee, which is especially important for shift workers. But have you ever noticed your chronotype shift when you go on holiday, especially when you holiday in the great outdoors?
To many people, the phenomenon known scientifically as the circadian rhythm is bleeding obvious. We sleep in the night and are awake during the day, long-haul flights like those from the UK to Australia gives you jetlag, and night shifts are a right pain in the bum. Detailed explanations involving transcription-translation feedback loops and phase response curves don’t change those facts, they’re a fact of life when we live on a rotating world. But many scientists, myself included, are fascinated in the details, and some scientists, like Céline Vetter and colleagues at the Institute of Medical Psychology at Ludwig-Maximilian-University in Munich, use this eye for detail to find out how we might best cope with our biological timing in a 24-hour society.
You can say all you like about lions or elephants being the coolest animals in Africa. They are awesome for sure but they’re not quite the top. I suggest that that title goes to the chameleon and the zebra.
Why? They are just so unique: one changes colour as much as a fashion model, and the other has a coat pattern unlike any other mammal. And thanks to two papers released this year, we’ve begun to understand a bit more about their unique skin.
Would you look at that! The story of mosquitos, cheese and body odour has taken another leap into scientific respectability with a paper being published in the pinnacle of journals, Nature. “Evolution of mosquito preference for humans linked to an odorant receptor” by McBride and colleagues was published towards the end of last year and looks at how the domestic form of the mosquito Aedes aegypti has evolved striking evolutionary adaptations that help it to find, bite, and spread disease to humans.
Two papers caught my eye recently that have taken advantage of the proliferation of whole genome sequencing techniques in recent years. With prices of sequencing whole genomes coming down and down, biologists are having access to vast amounts of data. The 1000 Genomes Project was one of the first to collect the vast amounts of human genome data into a story that told of human population origins. The two papers that I saw recently extend this story. One provides data from nearly 1500 people throughout the entire world to trace the genetic legacies of Ghengis Khan and Alexander the Great. The other delves deeper into the dawn of homo sapiens in Africa, over 300 whole genomes and nearly 1500 genotypes – the African Genome Project.
When I talk about my career and my interest in evolutionary biology, I often get asked, “How do you actually get new species?”. It’s not a stupid question; for people without a background in biology it really is very hard to imagine how the diversity of life we see today has formed from the types of ancient creatures we find in the fossil record. I normally look to my favourite fish, the Mexican blind cavefish, or point out the variety that can be produced in the single species of dog, or mention horizontal gene transfer to confer antibacterial resistance in bacteria, to show how even small changes can result in quite big differences in a species. Add to that vast amounts of time and it becomes a little easier to imagine the “hedge” of life taking shape.