Natural Selections

The octopus has held a fascination for people throughout the ages. Martha Foley describes a surfside encounter with beauty, and Dr. Curt Stager talks about the unusual qualities of this shelless mollusk, from its discernible intelligence to its oddball but efficient anatomy.

Kangaroos are marsupials, mammals who have a protective pouch in which they raise their young until they are developed enough to endure conditions in the outside world. What most people might not know is that the birth of kangaroos in a pouch is in some ways more complex than the birth and development of other mammals.Martha Foley talks with Dr. Curt Stager about kangaroos and their young, known as joeys.

The Eastern hognose snake is better known by its nickname, puff adder, derived from its aggressive display when disturbed. Its bite is mildly venomous, capable of sedating small prey, such as toads. Martha Foley and Curt Stager discuss this common northeastern reptile.

Bees need to be warm in order to fly. That's usually not a problem, since it takes millions of round trips to flowers to make a pound of honey. But should they fall idle long enough to cool down, bees fire up their wing muscles by shivering. Dr. Curt Stager and Martha Foley, with more about bees.

Most of the concern about carbon dioxide is focused on the quantity in the atmosphere and its effect on climate. But rising CO2 levels in the oceans can have equally significant effects on the ecosystems of the seas. Martha Foley and Curt Stager discuss the changing aquasphere.

The meteorological term "polar vortex" has a dramatic and ominous sound—the title of a disaster movie, maybe. But it is a just pattern of winds that is with us all the time and played a big role in recent deep cold snaps. They occur when the southern edge of this weather system pushes farther south than usual. Martha Foley and Curt Stager take a little of the hype out of this winter's weather buzz-word.

Bacteria have an awareness of when they are part of a large population, and change their behavior as a result. In the sea, bioluminescence is governed by this phenomena, known as "quorum-sensing." In the body, it may trigger the disease-causing effects of large infections. Martha Foley and Curt Stager get together with microbial crowds.

Martha Foley and Dr. Curt Stager talk about the role of individuals once they are past fertility. Elders help hold communities together by acting as the living histories and resource libraries.

Most color in nature is the result of pigments that reflect a particular wavelength of light, but some of nature's brightest offerings are created by physical structures within skin, scales and feathers that scattter and interfere with light.Martha Foley and Curt Stager talk about one of nature's flashier displays—irridescent bird feathers.

Dr. Curt Stager and Martha Foley explore the role of mitocondria—components that burn food molecules and produce energy—in cells.