What shade of green are you?

You Are Teal Green

You are a one of a kind, original person. There’s no one even close to being like you. Expressive and creative, you have a knack for making the impossible possible. While you are a bit offbeat, you don’t scare people away with your quirks. Your warm personality nicely counteracts any strange habits you may have.

What Color Green Are You?

Happy St. Patrick’s Day!

Yanoconodon, a new transitional fossil

A big tip and flourish to PZ Myers at Pharyngula for this detailed summary of an article from this week’s Nature. Yanoconodon, a primitive mammal, fills yet one more gap in the evolution of the inner ear bones from jaw bones:

“The latest Nature reveals a new primitive mammal fossil collected in the Mesozoic strata of the Yan mountains of China. It’s small and unprepossessing, but it has at least two noteworthy novelties, and first among them is that it represents another step in the transition from the reptilian to the mammalian jaw and ear.”

Ciliate nervous impulses

I was reading about one-celled animals the other day in the Big Book o’ Invertebrates. Ciliated animacules, or ciliates, have thousand of tiny cilia that beat in waves and propel them through water. Some ciliates are as large as 4 mm long, much larger than some multi-celled animals. For them to move, the motion of the cilia must be co-ordinated. Ciliates use a wave of electronic potential to do so. I was fascinated to learn that they use the same chemical system, namely potassium and chlorine ions as we do, to send nervous impulses throughout their protoplasm and stimulate motion. The difference is that their ions are not found in nerves and around nerve cells.

Some of them, such as the famous genus Paramecium, have pigmented eyespots that detect light, so that they can move towards light or shadow.

So we have at least two example of reducible complexity (nervous impulses without nerves, light detection without eyes) when we compare ourselves with paramecia. To me, common biochemical pathways imply probable descent from a common ancestor.

The illustration is from Living Invertebrates, so is presumably by M. K. Waldrip.

Genetic drift in evolution

This links to an excellent article, by Larry Moran of Sandwalk, on one of the basic mathematical concepts of genetics and how it connects to evolution.

“The two most important mechanisms of evolution are natural selection and random genetic drift. While most people have a reasonable understanding of natural selection, they don’t realize that random genetic drift is also important. The anti-evolutionists, in particular, tend to focus their attacks on natural selection, not realizing that there is much more to modern evolutionary biology.

“Charles Darwin didn’t know about random genetic drift but we now recognize drift as an important feature of evolution. This is one of the reasons why most modern evolutionary biologists no longer think of themselves as strict “Darwinists”. When you hear the anti-evolutionists equating “evolution” with “Darwinism” you know they haven’t done their homework!”

Follow the link to read more of this article and to find other excellent articles. (Hat tip to PZ Myers at Pharyngula.)

Invertebrate snacks

The Urban Pantheist has made Ammonites in a Blanket. Follow the link for a larger photo.

They are made with hot dogs, but at first glance I thought the tentacles were beet stalks.

In 2006, Urban Pantheist has documented 365 urban species.