Podcast: Play in new window | Download (Duration: 16:43 — 9.3MB) | Embed
For our final episode on the topic of natural history, we take a look at the Pleistocene. This epoch was the most recent ice age, and toward the end of this time, lots of the largest land mammals went extinct, while in the middle of the epoch, humans finally arrived on the scene.
…
Podcast: Play in new window | Download (Duration: 17:45 — 12.6MB) | Embed
Today we chat about the Miocene. During this epoch, kelp forest spread along the shoreline, creating habitat for otters and pinnipeds. The climate cooled and forest gave way to open grassland. Those grazing animals without the right kind of teeth died out, and the early apes diversified. Toward the end of the epoch, the branch of apes that would give rise to humans appeared.
…
Podcast: Play in new window | Download (Duration: 7:36 — 4.3MB) | Embed
The fossil record contains, at best, only a few percent of any given ecology during any given time. To complicate the picture, some of the fossils are fakes. From money to reputation to jokes, there are many reasons why such fossil hoaxes are perpetrated. Today we look at a few examples of, and motivations for, false fossils.
…
Podcast: Play in new window | Download (Duration: 6:20 — 3.6MB) | Embed
In the mid 1800/s some fossils were found in a tributary of the Illinois river, called “Mazon Creek.” They had simply weathered out of the ground, but it wasn’t until coal mining moved in, that the true extent and value of the Mazon Creek fossil deposit was discovered.
…
Podcast: Play in new window | Download (Duration: 5:36 — 3.3MB) | Embed
When a creature dies and becomes buried, sometimes its remains can completely rot and dissolve away, leaving a hollow space within the rock called a mold. If that mold becomes filled with sediment and water, it can harden into rock, becoming a cast. Every so often, the same sort of process can happen within the body of an animal, providing a stone cast of some of its internal arrangements. If that happens within the brain case of a skull, it’s called a brain cast. In 1924, a brain cast found in South Africa caught the attention of British anatomist Raymond Dart. After removing the fossil from the rock with his wife’s knitting needles, he was left with the first few skull fragments of Australopithecus africanus, or “southern ape of Africa,” to be discovered.
…
Podcast: Play in new window | Download (Duration: 5:48 — 3.3MB) | Embed
The semiprecious stone amber is fossilized tree resin. Sometimes, insects and other small critters are trapped by sticky tree sap, and become encased in amber. Sometimes, microorganisms are found inside amber. Sometimes, they’re yeast that can be revived and used to brew beer.
Here’s an article about the yeast, revived and used to brew beer.
Amber Ale: Brewing Beer From 45-Million-Year-Old Yeast
Here’s the homepage of the folks who used ancient yeast to make beer.
Podcast: Play in new window | Download (Duration: 8:51 — 5.2MB) | Embed
There are different candidates for the oldest preserved human footprints in North America. The older sight has a less certain date than the younger one. Today we look at ways of dating fossils, other than using carbon 14.
…
Podcast: Play in new window | Download (Duration: 7:45 — 4.5MB) | Embed
It took a bit of digging, but I found out why the domestic dog fossil found with the remains of the La Brea woman didn’t cause more of a sensation. Using carbon 14 dating, the dog fossil turned out to be around seven-thousand years younger than the fossil of the woman. What is carbon 14 dating, and how does it work?
…
Podcast: Play in new window | Download (Duration: 6:59 — 4.1MB) | Embed
The La Brea Woman was found in close association with the remains of a domesticated dog. Her remains have been dated to between 9,000 and 10,000 years ago. Were there dogs that early in North America? How long ago were dogs domesticated?
…
Podcast: Play in new window | Download (Duration: 5:18 — 2.9MB) | Embed
Fossils aren’t just remains of animals. Some of them are materials and marks left by organisms as they went about their lives. Called “trace fossils,” they are, instead of a snapshot of death, a snapshot of life.
Here are some articles about the traces humans left on our moon.
On the Moon, Flags & Footprints of Apollo Astronauts Won’t Last Forever
New Images Offer Sharper View of Apollo Sites
Here are some articles about some 190,000,000-year old dinosaur footprints.
Visit This Massachusetts Park With Dinosaur Footprints
And here are some articles about some 3.7-millean-year old footprints, left by some of our early ancestors.