Category Archives: biology

Digging around inside nature’s giants

Credit: Windfall/Richard Taylor/Jones

A sperm whale’s penis has no bones. This allows its flexible member to penetrate a female sperm whale from any number of directions; a necessity when two multi-ton animals are trying to line up tab A with slot B in an unsteady ocean environment.

This and other interesting facts about sperm whales are the subject of the first episode of the documentary series Inside Nature’s Giants, which premiers in the U.S. on January 18th. Each of the series’ four episodes centers around the dissection of a large animal, which is used as a starting point to explore the animal’s biology. (A clever device, which I also used in this Scientific American video about jumbo squid.)

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A crocodile’s salt water surprise

Crocodile near the beach in La Manzanilla, Mexico

It was a bit unsettling to see a crocodile occupy the same several square meters of ocean where I’d swam only a few days before. The croc must have been over ten feet in length and appeared suddenly and silently in the surf near the beach. He was probably chasing after a morning meal of fish. Unfortunately (or fortunately, depending on how you look at it) this beach is where I happened to be eating breakfast with my family. We had planned to spend the day swimming in the same stretch of water now occupied by the croc.  It was Thursday and earlier in the week this is where we’d been swimming, body surfing and even taking my 16 month-old niece Lucia for a dip.

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Lizard bite force

Here is a fun and informative video by scientist-filmmakers Neil Losin and Dan Nappen on the bite of the crested anole–a lizard native to Puerto Rico which has invaded South Florida. Neil is researching how the transplanted anole has adapted to its new environment by measuring its bite force, an indicator of food preference and level of competition with other lizards. The video has a great sound track and engages us with simple motion graphics that help elucidate where the research is taking place and how the Florida anole compares to its island-inhabiting progenitors. You can watch more of Neil and Dan’s videos on the website of their production company Day’s Edge Productions.

(Thanks to Bora Zikovic @BoraZ for the tip.)

Friday Fun…The Fantastical World of Biomedical Animation

One of the most frustrating things about working in biomedical research is the inability to translate infinitely small processes into something both visually meaningful and easy to digest.

Within every cell of our bodies is a chaotic symphony of molecular and chemical interactions that are difficult or impossible to see with the naked eye.  Scientists rely on experimental ‘snapshots’ to give them an idea of what’s happening at the microscopic level. Then they work backwards, reconstructing a sequence of events from these rather abstract clues.

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VIDEO: How The Flu Virus Jumps Species

Editor’s Note: This post was originally published on scienceofthetimes.com

In April, a new strain of H1N1 flu virus hopped from a pigs into people. This event sparked a pandemic that is now estimated to have killed 115 people and infected more than 17,000, according the World Health Organization. In the first video ever posted on Science of the Times, we explore how flu viruses can jump species.

TRANSCRIPT:

NARRATOR:

The flu virus can infect all kinds of animals from ducks to chickens, pigs, humans and even whales.

NARRATOR:

But scientists think that flu viruses in all of these animals, originally came from aquatic birds, like ducks.

DUCK:

Quack!

NARRATOR:

So how can a flu virus jump species, from birds, to other animals and ultimately to humans?

NARRATOR:

To answer this question,we need to look at the structure of the virus and how it survives.

NARRATOR:

Influenza is an RNA virus, meaning that it’s filled with strands of RNA,a genetic material similar to DNA. The outside of the virus is coated in proteins.

NARRATOR:

In order to infect a cell, the virus must dock up and deliver it’s RNA. A protein on the outside of the virus, known as hemagglutinin, sticks to receptors embedded in the cell’s outer membrane.

NARRATOR:

Once inside the cell, the viral RNA goes to work, co-opting the cell’s own molecular machinery in order to replicate itself and create proteins that will form new viruses. These new viruses, known as virions, disperse and infect other cells.

NARRATOR:

Humans CAN contract flu viruses from birds, but this rarely leads to an infection. The receptor proteins in birds and humans are different ENOUGH that the virus can’t easily dock to a cell.

NARRATOR:

However, viral RNA is not static. During replication, errors can accumulate and these can change the hemaglutinin protein just enough. Now the bird virus can infect the cells of other creatures, including humans.

NARRATOR:

But typically, that other creature is the humble pig. A pig’s cells have both the human-type and bird-type receptors. This means that both bird AND human flu viruses can infect a pigs cells. In other words, pigs act as a kind of viral middleman.

NARRATOR:

And it’s no coincidence that most flu pandemics of recent years are thought to have originated in South East Asia, where people often keep pigs and birds in close proximity.

NARRATOR:

What’s more, is that inside of a pig, flu viruses can become more infectious. Cells infected with both bird and human strains of influenza become incubators for new viral strains. The RNA can reshuffle, which could lead to new viruses with the worst traits of the two original strains.

NARRATOR:

Flu vaccines are a defense against viral infection. They stimulate antibodies against the proteins on the virus’ surface. This prevents it from docking and unloading its RNA.

NARRATOR:

But as long as the flu virus survives SOMEWHERE, in pigs for example, it can mutate again, changing its outer proteins and a newly infectious strain is born.