NOVA, the flagship science program on U.S. Public Television, has just launched a new Evolution Lab website, which is chocked full of great information about the history of life on Earth, and how we study it. But my favorite thing has got to be the accompanying online game, which asks you to assemble organisms into evolutionary trees based on their traits and even their DNA sequences — it’s slick and pretty and it guides you into the logic of evolutionary relationships without explaining them point-by-point, unless you want that. I’ll be keeping this in mind for the next time I teach a basic class in phylogenetics.
Humans are diurnal. We sleep at night and are active during the day. (That isn’t to say that I feel particularly diurnal most mornings, given that my alarm has to make it through a few snooze cycles to wake me up and coffee is the only thing keeping me from napping under my desk at work.) Most mammals, though, don’t share our ostensible predilection for daylight; only 20% of mammal species are diurnal like us. Of our mammalian relatives, nearly 70% are nocturnal. The rest are crepuscular (active at dawn and dusk) or cathemeral (active during both day and night).
Mammalogists like myself often think nocturnality is a particularly mammalian thing because—let’s be honest here—nearly all of the coolest nocturnal vertebrates are mammals. How can you compete with the likes of tarsiers, vampire bats, leopards, and—strangest of them all—the aye-aye? I’ll throw the ornithologists a bone and acknowledge the enduring awesomeness of owls, but they are the odd birds out in a group that’s mostly diurnal.
Currently there is a catastrophic outbreak of Ebola happening in West Africa. Over 1700 infections have been recorded with nearly 1000 deaths, making it the deadliest outbreak of ebola known. Infection results in a hemorrhagic fever, which starts out a bit like the influenza, but can result in bleeding from mucous membranes, organ failure, and ultimately death. But what is Ebola?
Ebola is a Filovirus. Filoviruses are a small group of viruses only known to infect mammals. They are so named because of their filamentous shape. They have tiny genomes, only ~19,000 base pairs in length, containing only seven protein coding genes and two regulatory regions. By contrast, the human genome is over 3 billion base pairs, contains around twenty thousand genes and has innumerable (by which I mean as yet unnumbered regulatory regions). Because of ebola’s simplicity, (as with all viruses), it cannot reproduce without commandeering the cellular machinery of its hosts. In the words of Cormac McCarthy, These anonymous creatures… may seem little or nothing in the world. Yet the smallest crumb can devour us.
This is a guest post by Daniela Vergara, a postdoctoral researcher studying the genomic architecture of hybrid species of sunflowers and Cannabis in Nolan Kane’s Lab at the University of Colorado, Boulder. Daniela also blogs about science at A Ciencia Abierta. Check out her blog for a spanish version of this post.
Cannabis is definitely a cool plant. It has fun names like matanuska thunderfuck, jesus OG or trainwreck and it has been trendy among humans for a very long time (humans have utilized it for thousands of years). Despite this long history, and the fact that Cannabis is the most widely used recreational drug in the world , the genomics and the general the biology of these plants have only been partially studied. At the Cannabis Genomic Research Initiative (CGRI) at the University of Colorado Boulder we want to study this genus of plants for several reasons, including: (i) its medical significance, (ii) its importance in the biofuel, fiber, oil, textile and food industries, (iii) its long co-evolutionary relationship with humans as an ancient crop, and (iv) in general, because it is an exciting emerging study system in evolutionary biology.
Why should evolutionary biologists be excited about studying Cannabis?
In my part of North America, spring is finally underway after a long slog of a winter. The trees lining the streets of my Minneapolis neighborhood are lacy-green with budding leaves, flowerbeds all over the University of Minnesota campus are yellow and red and pink with daffodils and tulips, and violets are popping up in the edges of lawns everywhere I look.
Of course, all of this colorful display isn’t for my benefit. Showy flowers are an adaptation to attract animal pollinators. Some flowers are quite precisely matched to a single species of pollinator, but most flowers have lots of visitors. These less specialized flowers are still adapted for their attractive function, though—and this is the origin of pollination syndromes.
You know the type. Big, brown eyes. Cute, little nose. Long, striped tail.
Chipmunks are adorable and one of the more easily viewed yet still kind of exotic North American mammals (in my opinion). I worked on red-tailed chipmunks for my Master’s degree at the University of Idaho with Jack Sullivan. Sullivan (et al.) just published a review of all the chipmunk research that’s taken place in his lab over the past 10 years or so. Central to the review is the concept of divergence with gene flow (DGF), but let’s start with some back story.
In a pretty interesting example of cross fertilization between scientific disciplines, a recently published paper by Jashmid Tehrani uses phylogenetic methods borrowed from evolutionary biology to construct an “evolutionary tree” of fables related to Little Red Riding Hood.
Tales typical of Riding Hood are found mostly in Europe, but a series of stories sharing some features are found in Africa (involving an Ogre) and East Asia (The Tiger Grandmother). These have sometimes been considered to be part of the Riding Hood group, but there has been debate over whether or not they actually belong to another, closely related group found in Europe and the Middle East known as The Wolf and the Kids.