Archive for October, 2022

The Battle of Chickamauga and the Horrors of War

October 27, 2022

I can think of nothing more terrifying than being in combat with other human beings. Typical Halloween frights don’t scare me, but the thought of men wielding guns, tanks, combat aircraft, and conventional or nuclear-tipped missiles is very frightening. I sympathize with the people of Ukraine and especially the soldiers who are defending freedom and democracy in a large-scale war taking place now. In pop culture war and horror go hand-in-hand in movies and books. There used to be a comic book entitled Weird War Tales published from 1971-1983 by DC comics. The stories involved killing, maiming, torture, and psychological trauma with the added element of the supernatural. What better way to keep a kid awake late into the night? In reality war is horrible enough without a supernatural element.

Weird War Tales was a popular comic book from 1971-1983. For Halloween this year, I can think of nothing more terrifying than men killing each other at the behest of their governments.

The Battle of Chickamauga was 2nd only to Gettysburg as the bloodiest battle of the Civil War. A few months before this battle General Rosencrans of the Union Army outflanked General Bragg of the Confederate Army in a brilliant tactical maneuver and forced them to retreat from Chattanooga, Tennessee. The Union Army advanced all the way to the Chickamauga Valley in North Georgia. General Bragg wanted to retake Chattanooga, and he chose to attack the Union Army in the Chickamauga Valley on September 19, 1863. The Confederates had a manpower advantage here with 65,000 troops vs 60,000 Union troops. The Union lines held on the first day of the battle. On the second day Rosencrans mistakenly thought there was a hole in his line, and he blundered by rushing thousands of reinforcements to where there was no gap in his line. This created an actual gap in his line, and the Confederates pushed through, forcing the Union Army to retreat. The Union Army did fight a successful rearguard action to cover their retreat back to Chattanooga where they spent the winter. The Battle of Chickamauga left Confederates with 18,454 casualties and the Union with 16,170 casualties.

Map of the Battle of Chickamauga. The Union lost this battle due to a General’s blunder.
Union and Confederate soldiers killed each other in the woods and fields at this location. Snodgrass Hill is where Union troops successfully fought a rearguard action, allowing them to retreat back to Chattanooga.
Imagine dead bodies strewn about this split rail fence.
Staring down the barrel of a cannon. Some of the new repeating rifles had a longer range than artillery during the Civil War. Imagine hundreds of bayonet wielding soldiers running up this hill toward you, seemingly coming out of nowhere from the smoke, dust, and shadows.
Imagine trying to poke a hole through someone with that bayonet. Imagine trying to stop an enemy soldier from trying to poke a hole through you, when you just ran out of bullets.

This battle marked the first widespread use of the Spencer repeating rifle, a weapon capable of firing 14 rounds per minute compared to just 2-3 rounds per minute for the average rifle or musket of the time. Union soldiers were shocked at how fast they could mow down Confederate soldiers at once. It was a sign of what would happen in future wars. The bullets used during the Civil War, known as Minie balls, were so large they caused traumatic damage to any limb struck. This explains why there were so many amputations during the Civil War. Even modern medical technology couldn’t salvage a limb struck by a Minie ball. Amputation was the only treatment then, and if Minie balls were used today amputation might also be the only option. Anesthesia was in its infancy and not always available then. Getting a limb sawn off without anesthesia must have been a horrible ordeal

When southern apologists claim black people fought on their side, what they mean is yes, some of them brought their slaves with them. This slave saved his master from a gruesome unnecessary leg amputation by sneaking him out of the hospital. The richer soldiers brought their body servants with them. A body servant was a slave that helped their master get dressed (and probably helped them wipe their ass too).
This man fought for the Union at The Battle of Chickamauga. He later became a lawyer and unsuccessfully argued in front of the Supreme Court against the separate but equal educational system in Plessy vs Ferguson.

Following the Union defeat, General Bragg occupied the heights surrounding Chattanooga. He planned to lay siege to Chattanooga instead of directly attacking it. Many military strategists have criticized this decision. General Grant replaced General Rosencrans. Eventually, the Union Army chased the Confederates away from the heights surrounding Chattanooga. Over the winter General Grant improved Union supply lines in this region, and in the spring he unleashed General Sherman and his troops on the Confederacy, leading to Sherman’s march through Georgia and the ultimate defeat of the Confederacy.

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Open Woodlands at Chickamauga Battlefield Park

October 20, 2022

I visited Chickamauga National Battlefield Park last week for the first time in many years. We were in northwest Georgia to see my mother-in-law for a couple of days. She lives in the Chickamauga Valley, and I’m familiar with the natural history of the region. Next week, I’m going to cover the history of the battle itself along with the horrors of war (for my annual Halloween blog post), but this week I want to focus on the natural history of the park. The landscape consists of large, mowed fields bordered by open woodlands.

Turkey and deer thrive in this type of environment.
An open woodland is defined as an environment with 50%-75% canopy cover. A forest is defined as an environment with >75% canopy cover. I estimate this is woodland, not forest.
Some of the trees here grow quite large.
Men were shooting, stabbing, and clubbing each other to death at this site 158 years ago.

An open woodland is defined as an area with 50%-75% tree canopy cover, while a forest is considered an area with >75% tree canopy cover. A woodland has widely spaced trees that allow enough light for grass, and shade intolerant shrubs and saplings to grow. Species of trees I found growing at Chickamauga Battlefield Park included white oak, black oak, northern red oak, scarlet oak, willow oak, black walnut, hickory, southern sugar maple, box elder, tulip, ash, Kentucky coffee tree, cedar, shortleaf pine, and loblolly pine. Botanists believe chestnut was formerly a co-dominant tree here on soils underlain by dolomite, but chestnut blight wiped them out a century ago. Many of the trees in the park now are over 100 years old. Shallow well-drained acidic soils predominate, and they are underlain by dolomite, limestone, shale, and sandstone.

Cedar trees are not fire tolerant. Open woodlands at this site are maintained by mowing and a high population of foraging deer, not fire.
This is either field thistle (Cirsium discolor) a native of North America or bull thistle (C. vulgaris), a native of Europe that has colonized North America. Enough sun reaches the woodland floor that shade-intolerant species can grow. Thistles attract many species of bees and butterflies and seed-eating birds.

Open woodland has probably been the most common environment on this site for millions of years. During the Pleistocene, megafauna foraging, ice storms, and windy conditions likely prevented the tree canopy from getting thick. More recently, Indians set fire to the woods frequently, thus keeping tree canopy open with thermal pruning. Now, I hypothesize a high density of white-tailed deer is keeping this woodland open. There is no hunting inside the park, though it occurs in adjacent areas. I suspect herds of deer find refuge here, and they thin out saplings with their hungry appetites. This habitat is ideal for deer and turkey, and I saw both while driving through the park. Road-killed coyotes are a common site on nearby roads. Fox, skunk, raccoon, possum, squirrel, woodchuck, and rabbit can be found in the park too.

See also: https://markgelbart.wordpress.com/2021/05/20/deer-herbivory-alters-plant-and-bird-species-composition/

Reference:

Wharton, Charles

The Natural Environments of Georgia

Georgia Department of Natural Resources 1978

The Fascinating Mystery of Homo naledi

October 12, 2022

Homo naledi, an extinct species of human not ancestral to Homo sapiens, is known from just 1 fossil site in the entire world–Rising Star Cave in South Africa. The remains consist of 15 individuals that apparently were buried in the same location over time. They were discovered during 2013 and anthropologists believe they were deliberately buried, though Homo naledi had a much smaller brain that modern humans. The discovery spawned a fascinating mystery. Why did a primitive species of human bury their dead in the same location? Anthropologists don’t believe humans with such a small cranial capacity could have a concept of an afterlife. The burial pit is pitch dark. They must have used torches to see inside the chamber, but anthropologists don’t think humans this primitive could have mastered fire. Some anthropologists don’t think the site is a deliberate burial pit. They suggest the bodies were simply thrown down a shaft or were carried by flood water. However, the majority of anthropologists who have examined the evidence do believe the bodies were deliberately buried.

Scientists used a variety of dating techniques to determine the age of the Homo naledi remains including uranium-thorium decay, optically stimulated luminescence, electron spin resonance, and paleo-magnetic analysis. They determined the bones range in age from 414,000 years BP-236,000 years BP. This means Homo naledi co-existed for a while with our ancestors: Homo erectus or maybe even Homo heidelbergensis. An anatomical analysis determined they shared characteristics with Australopithecus and Homo genuses, but they should be placed in the latter genus. They could walk upright just like us, though they were better climbers than modern humans. On average adults were less than 5 feet tall and weighed less than 100 pounds. Dental evidence suggests they are dirt-covered roots and bulbs. The location is some distance away from an area rich in game, so they may have existed in a spot where predators such as leopards were less common. They probably used tools. No other evidence of this species may ever be discovered. They diverged from our ancestors at least 900,000 years ago, and we likely will never know very much about our distance cousins.

References:

Dirks, P., et. al.

“The Age of Homo naledi and associated sediments in the Rising Star Cave, South Africa”

Evolutionary Biology May 2017

Irish, J., et. al.

“Ancient teeth, Phenetic Affinities, and African Hominins: Another Look at where Homo naledi fits in”

Journal of Human Evolution 122 September 2015

Missing Pieces of the Ecosystem

October 6, 2022

The extinctions of Pleistocene megafauna had a profound impact on ecosystems. Large herds of megafauna with the exception of bison were no longer foraging, trampling, and defecating on the landscape in North America. Plant communities were altered, and many predators and scavengers disappeared when all that meat was no longer available. A new study of fossil bones from sites located in the Edward’s Plateau, Texas examined some of the changes in the surviving fauna following the extinction of late Pleistocene megafauna. The authors of this study looked at bone chemistry to determine diet of species before and after extinctions, and they also estimated average size based on fossil remains (in some cases just the teeth). (I should note studies based on stable isotope analysis should be viewed with caution. See: https://markgelbart.wordpress.com/2016/06/24/trust-the-coprolites-not-the-stable-isotope-analysis/ )

Edward’s Plateau, Texas. Study area of the below reference.

The Edward’s Plateau is located in the middle of the North American continent and hosted species from the West, East, and those that had a continental distribution. During the Pleistocene there were grazers, browsers, and mixed feeders. Grazers included mammoths, bison, and horses. Browsers included mastodon, deer, pronghorn, tapir, llama, rabbits, and hare (jackrabbit). Gompotheres, camels, and peccaries were mixed feeders. The authors of this study could not obtain data from ground sloths, glyptodonts, and helmeted musk-ox to determine what they ate. Scientists found saber-toothed cats (Smilodon fatalis) and scimitar-toothed cats (Homotherium latidens) both had a specialized diet of juvenile grazers that were still nursing. These predators fed mostly upon young mammoths and bison that were still dependent upon their mother’s milk. Elephants lactate for up to 3 years after giving birth. Still nursing mammoths faced danger when they wandered away from the safety of the herd. Giant lions (Panthera atrox) and dire wolves (Canis dirus) had more generalist diets, eating grazers and mixed feeders. Black bears mostly ate plants. The lone specimen of giant short-faced bear (Arctodus simus) in this study had a diet similar to the striped skunk. Strange as it might seem, this giant bear was eating insects, mice, and fruit. Jaguars replaced other large Pleistocene predators as the main predator of juvenile bison and horses, following the extinctions of proboscideans, saber-tooths, giant lions, and dire wolves, but only for a short period of time. Horses are absent in the fossil record during the early Holocene, but this study and others suggest they lingered for a while after other Pleistocene megafauna went extinct. Eventually, jaguars become absent in the fossil record of this region, though historical accounts indicated they occurred as far east as Louisiana into historical times. They probably occurred in low numbers in this region. Cougars, formerly absent in the fossil record from this region, became more common.

In the Edwards Plateau, Texas jaguars temporarily replaced saber-toothed cats as a predator of juvenile bison and horses during the early Holocene about 10,000 years ago. Jaguars eventually became rare in this region too. Chart from the below referenced paper.

After the extinction of Pleistocene megafauna surviving herbivores responded differently. Deer and hare became larger, while cottontail rabbits and bison grew smaller. Hares and rabbits shifted to a diet of plants preferred by grazers.

Reference:

Smith, F., E. Elliot Smith, A. Villegenor

“Late Pleistocene Megafauna Extinction Leads to Missing Pieces of Ecological Space in North American Mammal Community”

PNAS 119 (39) September 2022