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Someone once asked why I go to so much trouble to answer such weird questions. To paraphrase George Carlin… The reason I answer these questions myself is because I’m the only one whose answers I accept. :) Okay, think about this. There are plenty of green birds, green reptiles, green amphibians, green fish, green insects… why aren’t there any green mammals? Wait… the Grinch is green. Is the Grinch a mammal? Honestly, I don’t know what he (or she?) is supposed to be. Anyway, the Grinch is fictional, so we still have no green mammals. There may be some mammal species humans haven’t discovered yet, but it’s fair to assume none of them will be green, based on the approximately 6,640 mammal species known so far that are not green. The closest we have to a green mammal is the two-toed and the three-toed sloths. Their fur sometimes appears to be green. But this isn’t part of the sloth’s natural pigmentation. Instead, sloths have a symbiotic relationship with green algae. The sloths provide the algae with a nice place to live, in the special grooves of their hairs where there is moisture. In return, the algae makes the sloth’s fur appear green, which serves as camouflage, protecting the sloth from predators (such as the massive harpy eagle, which loves to eat sloths). Okay, so besides the fictional grinch, and besides sloths that look green but are not really green, why are there no green mammals? The color of skin and hair in mammals is determined by two forms of melanin (pigment). Eumelanin varies from dark brown to black. Pheomelanin varies from yellow to red. Various combinations of these allow mammals to have colors ranging from white (no pigmentation at all) to black (dense quantities of eumelanin), with all ranges of brown and blond in between. However, it’s also important to understand that not all animal coloration is produced by melanin. Many animals have what is called structural coloration. Basically, this is a repeating structure at the microscopic level causing light to reflect a certain color. This is how most butterfly wings get their colors. And how some bird’s feathers get their colors. For example, a scarlet macaw doesn’t really have red feathers… but the feathers have a structure that interacts with light in such a way that only red light is reflected. And most birds that are green do not actually have green pigment, but instead they have structural features that reflect green light. This begs the question… if mammals don’t have any green pigment, couldn’t they evolve green structural coloration? Possibly. But, this fact also suggests that most mammals are better off with shades of brown. Even those mammals that climb trees a lot, like squirrels, are often seen against the tree bark rather than out at the tips of limbs surrounded only by green leaves. So, maybe part of our answer to this question is that few mammals actually need to be green. Below is a three-toed sloth in Costa Rica that has green algae living in its fur. 
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Trish recently spotted this spectacular pillbug (FIRST IMAGE) and held it for me to take a photo. Not only was this individual extra large, it also had an unusual pattern of yellow markings I hadn't seen before. Most of the ones I've seen are just slate gray in color. First, let's sort out what the heck a pillbug is. You might know them as roly-polies (because they roll into a protective ball when disturbed or dehydrated). They are often called isopods, because they are in the order Isopoda. Other names include pill woodlouse, potato bug, slater, and doodle bug. This color pattern got me curious, so I went down a Google rabbit hole and discovered that genetic color variations are fairly common in this species, Armadillidium vulgare, the common pillbug. In fact, some people keep them as pets, selectively breeding them for these yellow color patterns. By the way... back in the years when I taught 7th-grade science, I developed a research study with my students, in which we formed partnerships with other middle school classes around the United States. Each partner class collected pillbugs, and we conducted various behavior experiments to measure their preferences for temperature, moisture, light, and other environmental factors. Then I had all the partner schools exchange results to see how these pillbug behaviors vary in different parts of the country. It was a really cool project. For the culminating activity, I had students from all schools collaboratively write a multi-chapter sci-fi story featuring a sentient, time-traveling pillbug named Armadillia. I kid you not. The students from the various schools even drew illustrations for the story, and we created a book. The SECOND IMAGE is an example illustration. That's Armadillia with his portable time machine. Unfortunately, I can't give credit to the 7th grader who drew this picture because I don't remember who it was. My fascination with isopods shows up again in the Bridgers series. In "Bridgers 4: The Mind of Many," I populate a bizarre world with 2,000-pound isopods. These gentle giants, each the size of a hippopotamus, roam the wilderness in herds, feeding on moss (THIRD IMAGE). If you haven't read the Bridgers series, you're in for a treat. Check it out (https://www.amazon.com/Bridgers-Series/dp/B07GVDDM7S).    Photo Credits: Giant pillbugs in forest - Midjourney Other photos - Stan C. Smith I had an interesting encounter a few days ago. While I was exploring the forest near our home, I spotted a three-toed box turtle steadily (and noisily) making its way through the dead leaves of the forest floor toward me. I've always liked box turtles, so I just waited silently to see how close it would get before realizing it was walking toward a giant alien-like being. Well, the turtle didn't stop. Keeping its head turned slightly to its left, I saw that this turtle's right eye was missing. Unaware of my presence, it walked up to within inches of my feet. Then it turned its head, revealing an intact, functional left eye. It froze and stared. And it stared, and stared. This staring match continued until I could no longer take the judgmental scrutiny. So I spoke to the turtle... something like, "What happened to your eye, little dude?" Yes, I talk to forest creatures on a regular basis—don't judge. Instead of replying, the turtle finally turned and headed away. That's when I saw that its tail was just a little nub. I concluded that this turtle had been in a close encounter with a predator, probably years ago based on the appearance of the scars. It's a survivor. Respect.  Several unmistakable signs that spring is definitely here. These are things I saw in a recent hike in the forest. First, a prairie ring-necked snake (PHOTO ONE). These harmless snakes are common, and I usually find them hiding under flat rocks. Although you can barely see it in this photo, they have a distinct orange ring around their neck. These tiny snakes specialize in eating earthworms and slugs—yum! Notice the gray or milky eye? This tells me the snake is getting ready to shed its skin. Next, I found this five-lined skink sunning itself on a fallen log (PHOTO TWO). These lizards prey on just about any small animal they can catch, including insects, spiders, snails, and smaller lizards. They are incredibly fast, so sometimes you only catch a glimpse of one as it runs under the dead leaves to hide. The youngsters have bright blue tails. Next, numerous wildflowers are blooming in the forest, and the insects are out and about in abundance. PHOTO THREE is a carpenter bee feeding on flowers of a plant I'm pretty sure is dwarf larkspur. Carpenter bees are large, like bumblebees, but they are not aggressive at all. They do, however, like to chew perfectly round holes in the wood of our porch to make their nests. And finally (PHOTO FOUR), I only found this one single morel mushroom (morels were the reason I went on this hike in the first place). In Missouri (and other places), these mushrooms are legendary for their wonderful taste and their elusiveness. In April, morel hunters take to the woods in droves, trying to find these treasures. Some people are luckier (or more skilled) than others. As I said, I found only one. However, a few days prior, our son Ryan went out searching and found more than 300. These mushrooms only grow for a few weeks, so timing is everything.     I saw this question posted on FB, but no answer was provided. Well, I'm not afraid to tackle the big questions, so let's dig into this. “I need my beauty sleep.” I’ve heard this phrase uttered countless times, though I’ve never really understood it. The phrase dates back to the early 1800s. Its first use might have been when it appeared in Charles White’s 1828 book, "Herbert Milton." During that time, people widely believed that any sleep you got before midnight would enhance your health and beauty. Hmm… sounds to me like a way to get people to stop staying up so late. As for me, I am almost always asleep well before midnight… but I don’t think it has helped my beauty much. But why before midnight? Did people believe that, if you stayed awake until 12:01 AM, the sleep you got afterwards didn’t do you any good? That’s silly, so I’m going to file the whole midnight thing under “folklore.” Today, the phrase “beauty sleep” is usually used in a humorous way to refer to any good night’s sleep. Even so, the whole idea that sleep can enhance your health, appearance, and state of mind has persisted to this day. Is there any scientific basis to this? Does sleep really make us look better? Let’s examine what happens during a typical 7 to 8 hours of sleep. During the first three hours or so, your body starts producing a growth hormone called somatotropin, produced by the pituitary gland. As we get older, this hormone actually does help maintain youthful, healthy-looking skin. Without somatotropin, our skin cannot repair the damage that occurred during our waking hours. This of course would lead to physical signs of aging. Starting at about four or five hours into your sleep, your body begins producing melatonin, a hormone that helps regulate your sleep/wake pattern. It also acts as an antioxidant that helps protect your skin. Also, during the final three hours, your body goes into your REM stage of sleep. This is when your body’s stress hormone (cortisol) decreases. Your skin drops to its lowest temperature of the night, and your muscles relax, which allows your skin to have its deepest recovery of the entire night. If your alarm wakes you up in the middle of your REM sleep, this reduces these benefits. When you don’t get enough sleep, your body interprets this as stress, and stress has all kinds of effects, including more acne and drier skin, not to mention puffy eyes and that general sleep-deprived face we all experience at times. There you go… there really is a scientific basis for the old saying. So, be sure to get your nightly beauty sleep.  |
Stan's Cogitations
Everyone needs a creative outlet. That's why I write. |
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