Giraffe Evolution

I’ve known for some time that giraffes and okapi are related. But in looking up giraffe evolution, I’ve discovered that giraffes are also (distantly) related to pronghorns, deer, musk deer, cattle, goats, sheep, wildebeests, and antelope. What a wide-ranging family! However, the opaki are their closest relative, so close that a 7-million year old fossil had a neck that was a blending of a giraffe neck and an opaki neck.

Giraffe and opaki ancestors once roamed all of Eurasia, but in modern times, they are only found in Africa. Giraffes live in the savanna grasslands, while okapi live in the rain forest.

One possible early ancestor of giraffes is the Canthumeryx, which lived in Libya. No one is sure when it lived; guesses range from 25 million years ago to 14.3 million years ago. It was a medium-sized animal, slender and antelope-like.

About 15 million years ago, Giraffokeryx appeared in the Indian subcontinent. It may have resembled an okapi or a small giraffe. It showed some definite lengthening of the neck.

The Sivatherium ranged throughout Africa and to the Indian subcontinent about 1 million years ago, and may have gone extinct as recently at 8,000 years ago, as ancient rock paintings greatly resemble them. The picture of a reconstruction of one show a pair of horns that look rather like the horns of a Texas longhorn, but only about a foot long each. The neck wasn’t as long as a modern giraffe, and the spots are depicted as being not quite so regular. It stood 7.2 feet tall at the shoulder, with a total height of 9.8 ft and a body weight of up to half a ton. Its shoulders were very strong to support the neck muscles required to life the heavy skull.

There was another giraffe-type animal that ranged from India to Turkey called the Bramatherium, which was closely related to the Sivatherium.

The Shansitherium was a superficially moose- or antelope-like giraffe from the Shanxi province in China. They were closely related to the Samotherium, which was rather like a half-way point between a giraffe and an opaki, as far as size goes.

Giraffes have horns! They are actually called ossicones, being made of bone and covered in furry skin. Some of their ancestors had 2, like modern giraffes, and some had 4. Sometimes they stuck up, or stuck up and curved back, or maybe they stuck out vertically. The Sivatherium horns as I described looked like small longhorns, did not look to be covered in furry skin, but they also had a pair of ossicones above their eyes.

So, if I ever want to make up a giraffe-like alien creature, I now know there is plenty of leeway for using my imagination!

https://evolution-institute.org/how-giraffes-evolved-such-a-large-neck/

https://en.wikipedia.org/wiki/Giraffidae

Tyra

 I thought I’d take a look at Tyrannosaurus Rex. We all remember Tyra, right? Always represented as having a mighty roar and sharp, pointy teeth, and teeny, tiny forearms that wouldn’t even reach its mouth. Why would it evolve with such useless arms?

The first thing I discovered was that those tiny arms were quite strong, and each ‘hand’ had 2 sharp claws. So in a fight, if its mouth was already full of opponent, or it was still looking for the chance to sink its teeth into an opponent, those claws could be used to protect its belly, maybe? Well, not its abdomen, but the chest area. Any attack below that would call for leg action, either to stab or slice with its bigger foot claws, or to back up and get those fearsome teeth involved.

Other uses for these arms have been suggested; that they were used to grasp the female during sex, or that they assisted Tyra in rising from resting on the ground. Or from falling down, or being knocked down, or whatever. But one suggestion is actually supported by biomechanical analysis, and that is that the arms held Tyra’s struggling prey as the teeth did the work of killing it. Those arms are almost always shown bent at the elbow and held close to the body. And there’s a reason for that; Tyra’s shoulders could only move 40°, and its elbow only moved a maximum of 45°. So, no charades or sign language for this creature! To help you think about that, a healthy human shoulder can move 360°, while the elbow allows 165° of movement.

I had trouble picturing these restrictions. If you want, try this: Hold your arm down along your body and bend your elbow to make the forearm perpendicular to your body. This is your starting position. Now, keeping the elbow stiff in that position, raise your upper arm to not quite half-way to being perpendicular to your body. That is about how much Tyra’s shoulder could move. Now, extend your forearm to halfway between where it is and it being straight at the elbow. Imagine all the things you and I would not be able to do if that was all the further we could move those joints!

Okay, so these tiny arms may have been somewhat useful, but why did they evolve that way? What were Tyra’s ancestors like? And are there any descendants still around?

It was hard to find anything definitive about ancestors. The family tree that includes Tyra has many branches in that same time period, and they all seemed to have ‘stunted’ arms. A recent discovery from an earlier epoch held an almost complete skeleton of a very similar creature, possibly an ancestor of Tyra and/or other branches of that family tree. That article did not include much description - only that it was ‘horse-sized’ compared to Tyra’s ‘elephant-size - but the ‘artist’s rendering’ showed that ancestor as a skinnier Tyra, with somewhat longer and looser arms. That article stated that the ancestor already had a big brain, keen eye-sight, and sharp hearing at lower frequencies, and deduced that the Tyra family had developed these ‘smarts’ before it developed the brawn.

And of course, when the meteor hit and killed almost all the herbivores, a few Tyras - out of sheer desperation - shed over 99% of their weight, sprouted feathers and became birds. No, not really. When the herbivores died, Tyra’s family tree died, too. But some distant relatives - the maniraptoriformes family - did live on, and some of those did develop into modern birds. Which is good, because those tiny, practically frozen arms of the Tyra family were not going to launch a Tyra into the air, no matter how many feathers it had!

And now I’ll be shoving all this information into the grist mill that is my day-dreaming mind. Perhaps, on another planet, the end of the dinosaurs did not happen quite so fast, and the Tyras did manage to slim down and learn to fly. What do you think? Some kind of bird? Or dragon? Or something else entirely?

https://en.wikipedia.org/wiki/Tyrannosaurus

http://www.abc.net.au/news/science/2016-03-16/pregnant-t-rex-discovery-sheds-light-on-evolution-of-egg-laying/7251466

http://www.abc.net.au/news/2016-03-15/t-rex-tiny-ancestor-could-hold-clue-to-predator-dominance/7246928

Prehistoric Groundhog

Groundhog Day happens in February, when everybody - it seems - wants to know ‘Will this winter never end?’ How groundhogs ever got associated with predicting the end of winter is a mystery to me. Did any of them ever get a degree in climatology? No, not a one. They just lay in their borrow, blissfully sleeping through the cold when someone sticks his hand in, grabs one and pulls it out. Still blinking, the confused and shocked groundhog is held up high as a display, a crowd cheers and claps, and then... I don’t know, maybe they stuff the rodent with sweet treats as a reward for being a good sport. Not that the poor guy had any choice in the matter.

I started thinking, ‘Where do groundhogs come from?’ Yes, I know, from mommy and daddy groundhogs. What I mean is, millions of years ago, human ancestors were about the size and shape of a mouse, and they lived underground. Humans are a lot bigger now, and very few of us live underground. So, if we went back to that time - roughly 66 million years ago - would our ancestors be sharing burrows with ancient groundhogs? What would a groundhog from that long ago be like?

66 million years ago, all the southern hemisphere landmasses were gathered together into one supercontinent called Gondwana. Dinosaurs were still around, so I can’t blame our ancestors for seeking safety underground. Groundhogs of that day weighed 20 pounds (about twice the size of today’s groundhogs), had a skull 5 inches long and massive chewing muscles. Let’s see somebody pull one of those out of a sound sleep and hold it aloft!

A sample skull of the creature was found in a rock from Madagascar. This ancient groundhog was probably the largest mammal known for that time period, and lived on seeds, roots and nutty fruits. Its teeth included sharp incisors and wear-proof molars. Large eyes let it see in low light, and the intricate inner ear indicates it could hear higher frequencies than modern man can. A large nasal cavity means it had a keen sense of smell, and most likely it was agile. (The better to dodge large dinosaur feet?)

Alas, that particular rodent has gone extinct. So I’m not sure why it’s called a groundhog. I would assume a ‘prehistoric groundhog’ would be an ancestor of today’s groundhogs, but apparently, it’s only another branch on the family tree of groundhogs. A branch that broke, leaving other branches to fill in the hole.

Well, it did live in Madagascar, so it might have fallen prey to a blind snake, predatory frog or vegetarian crocodile, which were also Madagascar specialties.

www.theguardian.com/science/2014/nov/05/prehistoric-groundhog-vintana-sertichi-gondwana-dinosaurs

www.yahoo.com/news/prehistoric-groundhog-gets-day-204743464.html

www.newscientist.com/article/dn26696-peer-inside-the-head-of-a-giant-prehistoric-groundhog/

From Giant Dinosaur to Tiny Hummingbird

So, the theory is that Tyrannosaurus Rex gave birth to today’s birds, right?

Well, not exactly. T Rex was one of the of the theropod dinosaurs. It reached 40 ft in length, stood 12 ft tall at the hips, and weighed around 10 tons. However, other members of the theropod family were of various sizes, all the way down to 1 foot in length and 110 grams (3.9 oz) in weight. And throughout the ages following the T Rex, members of the theropod family grew smaller and smaller, and their skeletons changed four times faster than the skeletons of other dinosaur families. However, the theropods had hollow bones, like birds.

From what I’ve been reading, it isn’t terribly likely that birds evolved directly from T Rex, but they are both considered members of the theropod family. The largest modern theropod is the ostrich, 9 ft tall and up to 320 pounds. The smallest avian is the bee hummingbird, just over 2 inches long and weighing less than 2 grams. Although the theropods have shrunk since the days of T Rex, they continue with a wide range of sizes.

Ever wonder where birds got their feathers? The flying reptiles that nature started with didn’t have any. But the last decade or so, scientists have discovered non-flying dinosaurs that had feathers. How did that happen?

If I understood what I read, the transition began when some scales elongated into a filament. Over time, the filament developed ‘branches’, which eventually became numerous enough to form feathers. Scales and feathers are both made of keratin, and scientists have found that embryonic alligators contain some feather keratin, but that this type of keratin is suppressed in later stages of development in favor of scale keratin. Oh, and by the way, T Rex is more closely related to birds than to alligators.

Actually, lots of dinosaurs had feathers. Perhaps they didn’t grow feathers in order to fly, they grew them as insulation against the cold. And to look pretty to the opposite gender. Only later did the feathers help some glide from tree to tree and feathers started to become part of flying.

Are you up for a story about a T Rex covered in peacock and ostrich feathers?

Nomads

One of the panels I’ve given at several conventions this year has been “Where did the first Americans Come From?” In that panel, we discuss 6 different theories held by various scientists, from the one most of them agree is most likely to the one most people ridicule.

In doing my research for that panel-and just generally reading up on science subjects that spark my interest-I have arrived at one conclusion about humans and our ancestors... We have been nomads pretty much as long as we’ve been hominins. An article I read this past week has done much to confirm that, in my mind.

The article was actually about the Tibetan people and how they can thrive in the rarified atmosphere of the high altitudes where they live. Genetic studies have shown that most Tibetans (and a much lower percentage of the Han people in China) have an archaic gene. Not a mutant gene. An archaic gene inherited from a type of human that no longer exists.

This dead species of human is called the Denisovans. They are believed to have been related to-but distinct from-The Neanderthals (also extinct). And scientists probably would not know anything about the Denisovans at all, if someone had not found a single finger bone and 2 teeth in a Siberian cave. DNA study of those 41,000-year-old bones showed they belonged to people who were not Neanderthals, but definitely not modern human, either.

A genetic study of the Tibetan and Han people revealed they had inherited just enough Denisovan genetics to have the ability to up the production of hemoglobin in their blood. This increases their ability to get enough oxygen to their cells in an environment where most of us would have a tough time, due to lack of oxygen.

So, in order for the more modern humans to have bred with Denisovans (or the Neanderthals, for that matter) those earlier versions must have not just left Africa at some earlier time, but spread out across all of Eurasia. After all, Siberia is just about as far away from Africa as they could have gone. And later groups of hominins and humans would have exchanged DNA as they moved into the area, or passed through the area, or whatever.

If humans were not naturally nomads, they might never have left Africa, and then where would we be? Well, I guess we might all still be in Africa.

Encouragement

Years and years (and years) ago, when I was a young girl, fascinated with the notion of writing my own stories, I received encouragement from a cousin a couple years older. He told me such things as I would need to rewrite my draft, possibly more than once. I didn't want to hear it, but he was right. I found his stories funny, silly and delightful, and I basked in the knowledge that he was willing to spare a few minutes to encourage me in my endeavors.

We recently started communicating via the internet, and he revealed he had started writing again. (Again? I did give it up after a particularly horribly comment made by my first husband, and that was the blackest two years of my life.) I don't know how long he went without writing, but I was happy to hear he was re-discovering it.

And I guess we've come full circle. Now I find myself encouraging him. Have you thought about doing this with your story? Would it make more sense if your character did this? Your rough draft doesn't have to be perfect; rewriting is part of the process, remember?

Encouragement and suggestions from other writers are why authors join writer's groups and go to critique sessions. Another example is last year's critique sessions at Worldcon in Austin. I had been shopping around a fantasy, and kept getting rejected, so what I wanted to know was, is there something wrong with this opening that I'm not seeing? The comments I received gave me some direction for my next rewrite of that opening. I was thrilled.

If a writer's group or critiquer gives you the impression your writing is crap, don't go to that group or person again. My husband and I quit one writer's group because one person in the group kept pointing out our 'mistakes' without saying anything kind or nice about our efforts. That's not encouragement, and it's not helpful.

So, way to go, cousin! I really like what you've written, even though I'm not sure I like any of your characters. Your description in that story is great, it really sets the tone. Oh, and by the way... Welcome back to writing.

Dogs of the World

I like dogs. (I love cats, but that's another story.) Lately I've been reading a few articles having to do with the genealogy of dogs, particularly in the Americas.

When I was a kid, school described North American indian tribes as having horses and ponies. I was too young to question that at the time. Later, it was explained that the ponies originated with the Spanish explorers in Mexico, and that they quickly spread throughout North America. I assumed the indian dogs were a similar story.

But it turns out that dogs had already been here when the Spaniards, the Vikings, and other Europeans arrived. It had been assumed that when the indigenous people died out, their dogs died with them, having no one to take care of them.

These recent articles explained that the original 'American' dogs came over the land bridge from Asia and Siberia with the people who became indigenous indian tribes. Those dogs did not die out and were not supplanted by European dogs. They survived, interbred with the European dogs, and are still here.

This was discovered by comparing the DNA of American dogs with that of Asian and European dogs. The American DNA was much closer to the Asian DNA than the European DNA. This was true as far east as Greenland.

So the Mexican hairless, the Peruvian hairless, and any number of other breeds are about as American as they can get.

My family has a mutt. He's a great addition to our family, and I assume he's an 'American' mutt. How about you? Tell me about your dog.

Who's Your Distant Ancestor?

Back when I was in grade school, I remember one of my sisters preparing a display for her high school science fair project. In that project, she compared Neanderthals to Cro-Magnons. I don’t remember what kind of grade she received, but I found her project fascinating. Two types of humans, living at the same time! I wondered what their interactions would have been like.

Since then, the same question has been explored in various medias. Jean Auel’s Clan of the Cave Bear made a big splash with readers as it followed the life of a young Cro-Magnon, also known as a modern human, who was raised by Neanderthals, if I remember correctly. Various educational shows on TV have been made about the Neanderthals, the Homo Sapiens, how they were different, how they were alike, and how they might have interacted before the Neanderthals died out.

The impression I’ve gotten over all these years was that scientists didn’t feel these two species of humans had interbred, and I wondered why they thought that way. Neanderthals are depicted as kind of squat, hairy, with a heavy brow, broad noses and receding chins. I could look around and see people who had those attributes, although it’s usually one per person, not all of them. But no, it seemed we were determined to blame our own ancestors for killing the last of the Neanderthals.

At last, a skeleton has been discovered in northern Italy that appears to be that of a mixed breed. Although mostly that of a modern human, the jaw displays a receding chin. The DNA reveals this person had Neanderthal mitochondrial (maternal) DNA. So it would seem the two species did interbreed, at least once.

Which opens up a whole new mess of ancient ancestors we didn’t realize were in the gene pool.

Sometimes when I’m working out the background for a story, I pick 2 or 3 genetic things to track throughout the population and then work out how those attributes manifest in the population over the generations. The gene for dark hair, for instance, will dominate a gene for lighter hair, and blond will dominate red hair. But after a few generations of almost all the people having dark hair, you will start getting a generation or two of lots of blonds, and a few redheads will crop up. The number of blonds will ebb and flow; the number of redheads tends to remain fairly steady.

I never thought to track the occurrence of receding chins.

Name Confusion

Many years ago, I noticed that if a book had too many characters, I had trouble keeping track of them. If some of those characters had fairly similar names, I had no hope of keeping them apart in my head. I devised a method of avoiding that problem in my own stories.

Using that method has become so much a part of my process that I really didn’t pause to think about it any more. Until recently, when I started looking through papers I inherited from my mother about the family tree.

Have you ever looked through your family tree? I have been looking at one tree, the one that started with Jacob, born in 1800, and eventually resulted in me and my siblings, on my mother’s side. Families were pretty big back then, and apparently, the supply of names was limited. Take a look:

Jacob’s children included an Elizabeth, a Mary, a Robert, a Joseph, a John and a Charles. Yes, there were others, but I don’t have any bones with them.

Elizabeth and Mary both married a John, and their children (together) included an Elizabeth, a Mary, a Robert, a Joseph and 2 Johns. Two of Jacob’s sons married an Elizabeth, and both of those Elizabeths were the same age, and I don’t have a maiden name for either of them. So on that tree, I have 2 women designated as ‘Elizabeth ?, born 1835’. The children of these marriages include Mary, Elizabeth, Eliza, 2 Johns, Robert, Joseph, and Charles.

See what I mean about the supply of names being limited? 3 generations, and I am up to my neck in the same names, over and over again. Talk about confusion!

If I ever create a family tree for a book or series that I’m planning, … On the other hand, families do sometimes have a name or two that they pass down through the generations. My father’s name was Melvin; one of his brothers was Elvin. Not exactly the same, but close. My first husband had his grand-father’s name as his middle name; our son also had his grand-father’s name as his middle name. Not the same name, but follows a pattern.

Would my made-up family have such a pattern they follow, or a name they hand down through the generations? Maybe so. If they do, I’ll assign all the Johns and Marys nicknames that EVERYbody uses, just to avoid any name confusion.