Here’s a groovy new resource: Download the Universe is a site dedicated to reviewing the best of new eBooks in Science.
Download the Universe is a direct response to the changing publication landscape. In the words of the site’s founders:
It was clear that ebooks were becoming an extraordinary new medium, rivalling print books in the marketplace and offering opportunities that printed books could not. We saw great things in the future of science books. There was just one thing missing: a way for readers to find out about new ebooks about science. Book reviews were showing little interest; blogs offered scant, diffuse attention. We agreed that what was needed was a science ebook review. Here it is.
This is definitely one to bookmark or subscribe.
There has already been, since the late 1970s, much work done to show that whales and dolphins, collectively called cetaceans, evolved from exclusively land-dwelling mammals. Now it appears there is a case to be made that most of the fish we see in oceans today actually arose from freshwater ancestors.
96% of all fish on Earth are in the group called ray-fins. Research summarised by New Scientist shows that 75% of ray-fins share a heritage that arose in freshwater environments. They moved into pelagic habitats perhaps 170 million years ago.
So what happened to the organisms that never left the oceans? Mass extinctions, probably – for instance 95% of marine organisms were extinguished in the Permian-Triassic’s Great Dying – with freshwater habitats somewhat protected from disaster.
The video below has made an impression around the web in recent days, and dovetails nicely with a unit I’m currently teaching on electrical charge.
The astronaut, Donald Pettit, who created this and many other demonstration videos for NASA – available on the ReelNASA channel – is presenting here a variation on an experiment that can be done on Earth with a knitting needle or comb and a stream of water from a tap.
Have a go at doing this at home. It really is quite amazing.
What a great idea. I’ll let the owner of this blog speak for herself:
This Is What A Scientist Looks Like is a project developed by Allie Wilkinson to challenge the stereotypical perception of a scientist.
There is no single clear-cut path to becoming a scientist. A scientist can come from any background.
There is no cookie-cutter mold of what a scientist looks like. A scientist can look like you, or can look like me.
There is no rule that scientists can’t be multidimensional and can’t have fun.
Help change the way the world views scientists.
Sounds like a great idea.
National Geographic reported this week on the discovery, in Namibia, of the oldest fossils yet found of a multicellular animal.
At 760 million years old, Otavia antiqua is described as a sponge-like multicellular organism about the size of a grain of rice. These organisms were incredibly hardy, remaining relatively unchanged for 200 million years, and surviving at least two ‘Snowball Earth‘ events.
The previous oldest organism was also a sponge, and had been dated to 650 million years.
These organisms represent the earliest ancestors of all the multicellular organisms which have arisen since, from Dinosaurs to Humans.
Image courtesy Anthony Prave, University of St. Andrews
The BBC reports on research into a species of sea grass found in the Mediterranean Sea that may be tens of thousands of years old.
This grass, Posidonia oceanica, reproduces in such a way as to avoid the normal problems with cloning that introduce so-called ‘copy errors’ resulting in mutations which would otherwise limit the survivability of successive generations. By combining both asexual and sexual reproduction Posidonia has been able to grow in colonies up to 15km across on the sea floor for tens of thousands of years.
This research sheds light on how an organism can avoid damaging mutations from one generation to the next while adapting to changing environmental conditions.