Category Archive: Evolution

May 05

Adaptations evolve in populations

Pisum sativum (purple) [CC-BY-SA-3.0 Rasbak]

Organisms evolve adaptations to increase their fitness There are few ideas in science that explain as much of the natural world as does natural selection, but there are few ideas in science that are more frequently misunderstood. Often the misunderstandings are deliberate or disingenuous, but I’ve seen quotes like the one above even in undergraduate essays and …

Continue reading »

Jul 10

Phage vs. host

Phage vs. host [CC-BY-SA-4.0 Steve Cook]

For a recent schools’ outreach day, I put together a card-game based around the arms-races that develop between bacterial hosts and their viruses (bacteriophages). It’s mostly just a bit of fun, but if anyone finds it useful or can suggest improvements (or just make them! I release this under a CC-BY-SA-4.0 license) I’d be happy to hear them.

Mar 06

Organism of the week #20 – Don’t point that thing at me

Diadema setosum [CC-BY-SA-3.0 Steve Cook]

It’s amazing how informative an anus can be. Take this sea urchin. The orange pucker in the middle of the spines is its “around-the-bum”, although zoologists would insist on writing that in Greek as “periproct“. The bright orange ring-piece is characteristic of this species, and marks it out as Diadema setosum, rather than any of …

Continue reading »

May 26

Organism of the week #14 – Turtles all the way down

Cassiopea sp. [CC-BY-SA-3.0 Steve Cook]

Cassiopea, which looks rather like a spelling mistake (but isn’t), also looks a bit like an anemone (but isn’t): It’s actually a jellyfish, but one that spends most of its time living upside-down (relative to its relatives). Unlike its close relatives, it gets much of its energy from sunbathing rather than from fishing. Inside the cells …

Continue reading »

Apr 14

Down amongst the butterworts

I lived within 30 minutes’ drive of Charles Darwin’s house for the whole of my childhood. It’s been open to the public since it was acquired by English Heritage in 1998. I’ve been a biologist of sorts for about 18 years. It’s taken me until today to actually visit Down House, and to wander down …

Continue reading »

Apr 08

Organism of the week #11 – Not even primitive

Psilotum nudum (Oxford Botanic Gardens) [CC-BY-SA-3.0 Steve Cook]

It’s not much to look at, but Psilotum nudum‘s naked fronds hold a cautionary tale for biologists: Psilotum looks a great deal like some of the earliest fossils of land plants. One of the earliest such fossils is Rhynia, the first specimens of which which were unearthed in Aberdeenshire around 1910, a mere 410 million years after they were …

Continue reading »

Mar 30

Vegetable empire 2013

Paphiopedilum cv. [CC-BY-2.0 Alex Lomas]

By popular demand, I have resurrected this phylogeny from my old website for Easter 2013. I have added a number of extra groups, updated the angiosperms according to APG-III, and repositioned the Gnetales according the apparently ascendent gnetifer hypothesis. The rotated titles in the table appear to work in IE9, Chrome and Safari, but YMMV.   Classification …

Continue reading »

Sep 25

Far from the light of day, and somewhere near Hampstead

Paddock is the codename of a bunker that was built in the late 1930s as a back-up for the better known Cabinet War Rooms located in Whitehall. The bunker was abandoned at the end of the war, and was only used intermittently after that by the Post Office, whose Research Station sat atop it. In 1998, the surface site and the bunker were sold off, …

Continue reading »

Sep 10

A brief history of rubbish

C-value paradox [CC-BY-SA-3.0 Steve Cook]

In 1972, the geneticist Susumu Ohno coined the term “junk DNA” to explain why the genomes of closely related organisms vary so much in size: The mammalian genome […] contains roughly […] 3.0 × 109 base pairs. This is at least 750 times the genome size of E. coli. If we take the simplistic assumption that …

Continue reading »

Jul 26

The magnolia misunderstanding

Angiosperm phylogeny stressing magnoliids [CC-BY-SA-3.0 Steve Cook]: thistle appears as an outgroup to the ((magnolia,bay),(pepper,birthwort)) clade

T. Ryan Gregory has a great post at Genomicron on the ‘Platypus Fallacy’. He imagines a platypus professor explaining the wonders of the Human Genome Project to a group of student platypodes: “The lineage of which humans are a part is a very ancient offshoot of our mammalian family tree, so it was 166 million …

Continue reading »

Older posts «