Friday Headlines, February 7, 2014
THE LATEST IN THE GEOSCIENCES
Rehashing an old (or not that old) debate
Chickens with theropod tails
Big mammals might have gone extinct for lack of flowers
This happened on Tuesday evening. Bill Nye (The Science Guy) and Ken Ham (Answers in Genesis). They had a two hour debate about where the truth was, in Evolution or in Creation. You can watch it yourself and draw your own conclusions.
It’s accepted among paleontologists that modern birds evolved from theropod dinosaurs, like Tyrannosaurus and Velociraptor. An important distinction between fossil theropods and modern birds is the lack of a long, fleshy tail.
A group of paleontologists were curious to know how the addition of a long tail would affect the gait of birds, so they created prosthetic tails (that look a little like small plungers), attached them to the hind end of chickens, and watched how differently the birds walked.
Researchers found that the addition of the long tail caused the bird to walk with a slightly more crouched posture, resulting in more motion at the hip joint, than at the knee when compared to ‘tail-less’ modern birds.
About 10,000 years ago, many of the giant mammals of the world (including mammoths, mastodons, and woolly rhinoceros) went extinct. Paleontologists have been trying too understand what caused this extinction. The two most commonly cited hypotheses are climate change (the glaciers were receding then) or over hunting by humans. (I talk about some other hypotheses in this blog post.)
New research suggests that climate change resulted in a change in plants available for these huge mammals to eat. Abundant and nutritious flowering plants were replaced by less nutrient, harsher grasses and shrubs. Perhaps it was the loss of adequate food that led to the extinction of the giant mammals.