Students often get to look at hydras – tiny, fresh-water members of the group that includes sea anemones, jellyfish, corals, and the Portuguese man’o’war. All these cnidarians have a simple body-plan: two layers of true tissue with a jelly-like layer between them, a sac-like gut with a single opening that acts as both mouth and […]
Continue readingCategory: evolution
dogs, diets, & the impact of evolution
Yvonne d'Entremont (aka SciBabe) recently posted an article on 'alternative' foods and health products for pets, in her usual no-holds-barred style. It's always good to see pseudoscience called out for what it is, and in the case of pet-focused quackery it's a message that needs multiple repeats. Why? Because pets are dependent on us, & […]
Continue readingvegetarian spiders? what is the world coming to?
Like probably everyone reading this, I have always thought that spiders are carnivorous, sucking the precious bodily fluidsA from their prey. I mean, those fangs! And I was wrong, for it seems that some spiders eat some plant material alongside their liquid meals – and some are almost fully vegetarian. A just-published paper (Painting, Nicholson, […]
Continue readinghuman evolution – new discoveries, & how do we accommodate them in our teaching?
What follows is loosely based on a workshop I ran at this year's Biolive/ChemEd secondary science teachers' conference. (A most excellent conference, by the way – kudos to those organising & presenting.) I've added a bunch of hotlinked references. Back when I was in 7th form (or year 13 ie a rather long time ago), […]
Continue readingparts of our genome are actually viral
I've just come across a most excellent article by the Genetic Literacy Project. In it, Nicholas Staropoli notes that a proportion of the human genome actually has viral origins. This might sound a bit strange – after all, we tend to think of viruses as our enemies (smallpox, measles, and the human papilloma virus come […]
Continue readingselection and dog breeds
So, I own a pocket wolf. … … Oh, OK, I own a little black mini-poodle. But, like all dogs, he has the same number of chromosomes as a wolf! There've been several articles posted recently about the evolution of domestic dogs. While we've tended to think that domestication didn't begin until humans began to […]
Continue readingtunicates – apparent simplicity belies a complex past
Tunicates are more commonly known as 'sea squirts' – little blobby marine creatures that squirt water when you touch them (hence the name). We don't hear about them often, except perhaps when they make the news for all the wrong reasons. But from an evolutionary perspective they are fascinating little creatures – and it's largely […]
Continue readingthe bedbug genome and their bloody habits
Once upon a time, I wrote about traumatic insemination in bedbugs. (Those of my friends who are still traumatised by learning about the reproductive habits of various slug species may not wish to follow that link.) Now, two papers just published in Nature Communications describe the results of sequencing & examining the genome of the […]
Continue readingdragonfly eyes
Dragonflies are ancient: with damsel flies, they were among the earliest flying insects. An analysis based on molecular data and fossil evidence suggests a date of 480mya for the first insects, around the same time that land plants evolved, and includes a rather impressive family tree for the taxon; the earliest dragonfly fossils are around 325my […]
Continue readingcrossing the great (prokaryote-eukaryote) divide
I’ve always enjoyed Nick Lane’s writing1, so naturally an article he wrote for the ABC Science website caught my eye. Titled “Evolution of complex life on Earth, take 2?”, it discusses an organism that appears to be neither prokaryote nor eukaryote, but something in-between. There’s a great divide between the cells that fit the description […]
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