Category Archives: Animals

Exploring Eukaryotic Cells

This webcast is packed with information on the makeup and function of eukaryotic cells, which are the type of cells found in animals. It is part of a interesting series of science webcasts by Crash Course. The webcast style might be a bit too hyperactive and flippant for some but the content is quite interesting and the videos they are are of similar style and quality so if you like this one you can subscribe to their channel. They offer quite a few webcasts on science but they also offer webcasts on history.

Related: Plants, Unikonts, Excavates and SARsHow Cells AgeMidichloria mitochondrii

How Bee Hives Make Decisions

The Secret Life of Bees by Carl Zimmer

The decision-making power of honeybees is a prime example of what scientists call swarm intelligence. Clouds of locusts, schools of fish, flocks of birds and colonies of termites display it as well. And in the field of swarm intelligence, Seeley is a towering figure. For 40 years he has come up with experiments that have allowed him to decipher the rules honeybees use for their collective decision-making. “No one has reached the level of experimentation and ingenuity of Tom Seeley,” says Edward O. Wilson of Harvard University.

Enthusiasm translates into attention. An enthusiastic scout will inspire more bees to go check out her site. And when the second-wave scouts return, they persuade more scouts to investigate the better site.

The second principle is flexibility. Once a scout finds a site, she travels back and forth from site to hive. Each time she returns, she dances to win over other scouts. But the number of dance repetitions declines, until she stops dancing altogether. Seeley and his colleagues found that honeybees that visit good sites keep dancing for more trips than honeybees from mediocre ones.

This decaying dance allows a swarm to avoid getting stuck in a bad decision. Even when a mediocre site has attracted a lot of scouts, a single scout returning from a better one can cause the hive to change its collective mind.

“Bees are to hives as neurons are to brains,” says Jeffrey Schall, a neuroscientist at Vanderbilt University. Neurons use some of the same tricks honeybees use to come to decisions. A single visual neuron is like a single scout. It reports about a tiny patch of what we see, just as a scout dances for a single site. Different neurons may give us conflicting ideas about what we’re actually seeing, but we have to quickly choose between the alternatives. That red blob seen from the corner of your eye may be a stop sign, or it may be a car barreling down the street.

To make the right choice, our neurons hold a competition, and different coalitions recruit more neurons to their interpretation of reality, much as scouts recruit more bees

Very cool stuff.

Related: Honeybees Warn Others of RisksWasps Used to Detect ExplosivesStudy of the Colony Collapse Disorder Continues as Bee Colonies Continue to Disappear

Friday Fun: Exercise Wheels for Dogs and Cats

This would certainly give dogs that don’t have big enough yards to run in some good exercise.

Cats don’t seem to take to the wheels as naturally as a few dogs do. While the wheel is odd no matter what I would also wager the evolution of the animals is at play. Cats are use to stalking animals. You can see that trait play out in the kitten video above (and lots of other similar videos – so while this one is partially the kittens short attention span it also seems common that cats don’t just run for a long time). While dogs are evolved to wear our their prey in log distance chases. I’m sure getting dogs to use a wheel isn’t likely to be super easy but I think it will be easier than getting cats to do so.

Related: Kittens Reminding You to Thank Your MotherFriday Escape Dog FunFriday Cat Fun: Treadmill CatsDog and Duckling Fun

Our Genome Has Adopted Virus Genes Critical to Our Survival

Mammals Made By Viruses by Carl Zimmer

Viruses have insinuated themselves into the genome of our ancestors for hundreds of millions of years. They typically have gotten there by infecting eggs or sperm, inserting their own DNA into ours. There are 100,000 known fragments of viruses in the human genome, making up over 8% of our DNA. Most of this virus DNA has been hit by so many mutations that it’s nothing but baggage our species carries along from one generation to the next. Yet there are some viral genes that still make proteins in our bodies. Syncytin appeared to be a hugely important one to our own biology. Originally, syncytin allowed viruses to fuse host cells together so they could spread from one cell to another. Now the protein allowed babies to fuse to their mothers.

The big picture that’s now emerging is quite amazing. Viruses have rained down on mammals, and on at least six occasions, they’ve gotten snagged in their hosts and started carrying out the same function: building placentas.

Some mammals that scientists have yet to investigate, such as pigs and horses, don’t have the open layer of cells in their placenta like we do. Scientists have come up with all sorts of explanations for why that may be, mainly by looking for differences in the biology of each kind of mammals. But the answer may be simpler: the ancestors of pigs and horses might never have gotten sick with the right virus.

More amazing facts from science. This stuff is so interesting. Carl Zimmer is a fantastic science writer and he has written several great science books.

Related: Amazing Science, RetrovirusesMicrocosm by Carl ZimmerTen Things Everyone Should Know About ScienceParasite Rex

Friday Fun: Crow Sledding, Flying Back Up and Sledding Down Again

Great video of a crow sledding down a roof on a small intertube like thing (a lid?). Then it picks up the sled and flies back to the top and sleds down again. Awesome. The curious crow then flies off with its sled to try it out elsewhere (maybe).

Related: Bird Using Bait to FishCat and Crow Playing TogetherDolphins Play with Air Bubble RingsFriday Duckling Fun

Kittens Reminding You to Thank Your Mother

Fun cat video and a reminder to thank your mother for all the times she saved you from your version of the slide. Have a happy friday. Maybe you should forward this video to your Mom with a note of thanks and make it a happy one for her too.

Related: Friday Cat Fun #11: Ninja Cat Stair ClimbingNaturally Curious ChildrenTreadmill Cats: Friday Cat Fun #3Friday Cat Fun #13: Kitten in His Box