Our humble beginnings

What formed first, you may ask, our mouths or our anus? It’s not completely unlike asking, “What came first, the chicken or the egg?” The answer to both questions is the latter: the egg, and, at least for us human beings, the anus.

We human beings are deuterostomes, which means “second mouth.” Think of the book in the bible, Deuteronomy, which means “second book” or “second law.” Protostomes are those creatures whose mouth formed first, before the anus. They include worms, insects, crustaceans, snails, squid, and octopi. Deuterostomes include us, other animals with backbones like lemurs, lizards, salamanders, frogs, and also the echinoderms, spiny skinned creatures like starfish, sea urchins, and sea cucumbers.

Does this mean that we are more closely related to starfish than to octopi? It seems insufficient to count only the beginnings, when we may have taken different paths but arrived at similar places: with two eyes, and the keen intelligence to open jars to get at what’s inside.

Another surprise is that when the first cells divide after fertilization, they are determined in protostomes, but not for deuterostomes. Is this way a starfish are able to keep regenerating arms? Do the cells maintain that undifferentiated ability to become whatever is needed? And how were people able to determine that the early cells in deuterostomes remained undifferentiated? Did researchers actually go in and separate some cells of a fertilized egg/blastula, and all the separated cells became whole animals?

Source:

https://www.mun.ca/biology/scarr/Protostomes_vs_Deuterostomes.html

The Best Commuter Bicycle Gear

 

If you like to bike places: to work, to see friends, to go to the grocery store, and just to bike, breathing the air and feeling the breeze, all times of day or not, rain, snow, or shine, then here are a few bicycle gear items that may make a tremendous difference in the quality of your life:

Panniers.

Trust me on this one. Treat yourself. If you have been biking with a backpack for years, thinking ah, those pannier things look intriguing, but I don’t want to go through the hassle of getting a bike rack and buying panniers… think again. They are great. Consider investing in a pannier, yourself (all that extra biking you can do, getting milk from the grocery store), and the planet (one less car on the road).  Just make sure you try them out first to make sure you can install ones that are far enough back so you’re not going to hit them with your heels.

Fenders.

Keep your face from getting sprayed with oily water. Worth it.

Rain Pants.

Essential for biking in the rain, and staying warm in cold weather. Just make sure you also have those little velcro strap things (they don’t have to be attached to the pants, you can buy a couple separately) to keep the bottoms tight to your legs so that you don’t tear your pants on the gears.

Overshoes.

These are amazing. I’ve got some overshoes called Neos. They make bicycle commuting much easier in nasty weather conditions. Just pull them on over your boots. They have the added benefit in rainy weather of being high and waterproof enough to pull your rain pants over them, and velcro strap them tight to make a seal where water won’t run down into your boots or splash up underneath.

Happy biking! And read here for some safe biking tips.

HT to K.W. and the Pedal People.