Archive for June, 2018

The Adaptability of Pleistocene Peccaries

June 30, 2018

Two lineages of peccaries lived all across North America for over 5 million years but both became extinct about the time man appears in the archaeological record.  The long-nosed peccaries in the Mylohyus genus were forest edge species, and the flat-headed peccaries in the Protherohyus-Platygonnus genuses inhabited scrubby thickets.  A new study looked at dental microwear and bone chemistry in these lineages and compared them with the teeth and bone chemistry of the extant white-lipped peccary to determine the dietary similarities and differences of the extinct and extant species of peccary.  Peccaries in the Mylohyus genus co-existed with Protherohyus peccaries during the Miocene over 5 million years ago.  The former ate more woody browse and forest vegetation, while the latter mostly ate grass.  During the Pliocene between 5 million years BP-2million years BP both Mylohyus and Platygonnus ate mostly woody browse in Florida.  Their diets shifted during the early-mid Pleistocene with an increased consumption of grass.  During the late Pleistocene Mylohyus ate more forest vegetation such as twigs, acorns, and nuts, while Platygonnus ate more tough leaves and grass.  This study shows how adaptable these lineages were to environmental change–their diets shifted with changes in climate.  It seems obvious to me that overhunting and/or disruption of the overall ecosystem by humans, not whole scale environmental change, caused the extinctions of both Mylohyus and Platygonnus.  Surviving extant species of peccaries live in deserts and remote jungles where human populations remain sparse.

Image result for mylohyus nasutus

Image result for Platygonus compressus

Illustration of Platygonnus peccary.

Image result for white-lipped peccary

White-lipped peccaries eat forest vegetation.  They can be dangerous.

The proliferation of feral pigs (Sus scrofa) in North America today demonstrates how favorable the environment still would be for Pleistocene peccaries, if they still existed.  Pigs co-evolved with humans in Eurasia to produce large litters, making them capable of surviving human hunting pressure.  Pigs produce litters of 8-12, but peccaries only birth 2-4 young.

Some archaeologists reject the likelihood that humans hunted peccaries to extinction because there are no known kill sites, other than a peccary shoulder blade with a spear hole in it next to a spear.  See: https://markgelbart.wordpress.com/2014/03/10/the-sheridan-cave-pit-fossil-site-in-wyandot-county-ohio/

This is a ridiculous assumption. There are also no known white-tailed deer kill sites in the archaeological record, but we know Indians hunted deer.  Evidence humans killed Pleistocene peccaries simply faded away over time.

Reference:

Bradham, J. et. al.

“Dietary Variability of Extinct Tayassuids and Modern White-Lipped Peccaries (Tayassu pecari) as Informed from Dental Microwear and Stable Isotope Analysis”

Palaeogeography, Palaeoclimatology, Palaeoecology April 2018

 

Advertisements

New Study Supposedly Debunks Proposed Pre-Clovis Evidence from the Coats-Hines and Topper Sites

June 23, 2018

Archaeologists claimed they had “unequivocal” evidence humans butchered a mastodon at the Coats-Hines site located in Tennessee.  Now, some of these same archaeologists recently published a paper admitting their evidence was equivocal.  I wrote a beautiful article on my blog about the Coats-Hines site a number of years ago, and it always gets a lot of hits early during the school year because a teacher uses it as a reference for a school assignment.  Unfortunately, the assumption the site includes evidence of human-butchered mastodon remains may be bogus.  (See: https://markgelbart.wordpress.com/2013/04/15/the-coats-hines-pre-clovis-site-in-williamson-county-tennessee/ )

The Coats-Hines site is located adjacent to a golf course.  During construction of the golf course 40 years ago workers found the remains of a mastodon.  Further digging by trained experts over the years yielded the remains of 3 more mastodons, white-tailed deer, muskrat, turkey, and painted turtle.  This most recent paper noted the additional identification of ground sloth bones (probably Harlan’s) from the site.  A mastodon vertebrae apparently had cut marks on it, suggesting evidence of anthropogenic butchery, and it was associated with supposedly human-made artifacts.  In a paper published just 7 years ago the archaeologists wrote it was “unequivocal” evidence of human butchery.  However, in his more recent study Jesse Tune admits the cutmarks could’ve been caused by the bone being tumbled against rocks in an high energy stream environment.  He thinks the artifacts associated with that specimen are geofacts.  A geofact is a natural stone formation that resembles an human-modified object.  The stones come from local outcrops that naturally eroded into the stream.  There are definitive human-made tools at Coats-Hines, but they were found some distance away from the mastodon bones.  Coats-Hines was a former stream, and deposits of different ages can get mixed together when currents erode through different aged strata.

Jesse Tune used what he learned from studying the Coats-Hines site to debunk claims made for the antiquity of the Topper site in South Carolina, and the Burnham site in Oklahoma.  Archaeologists excavating these sites claim the evidence they found was older than the Last Glacial Maximum.  (The LGM dates to roughly between 18,000 years BP-22,000 years BP.)  Jesse Tune thinks the evidence at these sites consists of geofacts eroded from adjacent local outcrops that perhaps mixed with real artifacts of more recent origin in an high energy stream.

The new paper (referenced below) includes the Coats-Hines site as a proposed pre-LGM site.  This puzzles me because I can’t find anyone who ever claimed the artifacts and evidence from Coats-Hines dated to before 22,000 years ago.  The sediment around the mastodon bone thought by some to be butchered by humans produced a radio-carbon date of 13,100 years BP (~=15,000 calendar years BP).  This is well after the LGM.  I always considered Coats-Hines to be pre-Clovis but not pre-LGM.  It seems as if the authors of this paper are making a straw man argument because as far as I can determine, nobody claimed Coats-Hines was pre-LGM.

Image result for straw man

Who claimed Coats-Hines was pre-LGM?  I asked 2 authors of the below study but I didn’t get a response.  Are they making a strawman argument about Coats-Hines?

References:

Tune, Jesse; et. al.

“Assessing the Proposed Pre-Last Glacial Maximum Human Occupation of North America at Coats-Hines-Litchy, Tennessee and Other Sites”

Quaternary Science Reviews April 2018

Wolf, Aaron; Jesse Tune, and John Broster

“Excavations and Dating of Late Pleistocene and Paleoindian Deposits at the Coats-Hines Site, Williamson County, Tennessee”

Tennessee Archaeology 5 (2) Fall 2011

Pleistocene Puffer Fish (Spheroides maculatus)

June 16, 2018

Pier fishermen often catch what many consider to be “trash” fish.  Stingrays, eels, dogfish, and puffer fish are common in shallow coastal waters during the summer and readily take bait.  Although fishermen usually throw them back in the ocean, they are all good to eat.  Pieces of stingray wings cut with a cookie cutter are used to make mock scallops.  Eel is a delicacy I have enjoyed.  Dogfish, a small species of shark, really does taste like chicken when fried. During WWII when rationing made meat scarce, fishermen caught hundreds of thousands of pounds of puffer fish off Long Island and sold them in New York City fish markets under the name “sea squab.”  However, an important cautionary note needs to be made about consuming puffer fish–its flesh is toxic in some regions.  From researching this topic online, I’ve determined puffer fish caught from North Carolina to Massachusetts are safe to eat, but puffer fish caught from Florida south to the tropics are deadly.  It is against the law to consume puffer fish caught off Florida’s coast because it contains so much saxitoxin.  I have not been able to determine whether puffer fish caught in the border region in between Florida and North Carolina are safe, so I wouldn’t chance it.

 

Video of a man cleaning puffer fish caught off the North Carolina coast.  It yields a piece of fish about the size and shape of a chicken drumstick.

Image result for illustration of puffer fish before and after it blows up

Illustration of puffer fish before and after it blows up.

The northern Atlantic puffer fish, also known as a blowfish, is a member of the Tetraodontinidae family which includes 29 genera and 191 species.  Most of these species occur in tropical waters and are toxic.  The family includes the famous fugu fish served in Japan where specially trained chefs dress them in a way that makes them safe for human consumption.  Toxins are heavily concentrated in the liver and gonads.  Puffer fish inhale air or water when threatened, and they have prickly spines on their scales.  This makes them tough for predators to grasp or swallow.  Ospreys are unable to grab puffer fish.  This defense mechanism has helped this family survive for millions of years.  Definitive fossil evidence of species in the Tetraodontinidae family has been unearthed from strata dating to the Cretaceous over 100 million years ago, and some specimens that may belong to this family were found in Triassic deposits.

The northern puffer fish evolved to live in cooler waters than its tropical cousins.  Cooler ocean currents began to expand in circulation early during the Pliocene when Ice Ages began to occur.  This may be when the northern puffer fish diverged from the southern puffer fish (S. nephulus) which reaches its northern range limit off the coast of north Florida where the 2 species overlap.  In this area northern puffer fish inhabit deeper waters to avoid competion with S. nephulus.  Northern puffer fish move into shallow waters over most of the rest of their range during summer but move to deeper waters when the water temperature seasonally cools.  This pattern may have been disrupted following Ice Age Heinrich Events when  the Gulf Stream shut down due to influxes of glacial meltwater.  There is no known Pleistocene-aged fossil evidence of puffer fish, and scientists have not yet studied the Tetraodontinidae family genome.

Puffer fish prey on crustaceans (schools of puffer fish gang up on blue crabs), molluscs, worms, and sponges; and they consume seaweed and algae. The species of algae they eat in warmer waters is toxic, and this is how they acquire their toxicity.  This explains why the same species is safe to eat when caught from cold waters but toxic from warmer regions.  There is no antidote for this kind of nerve poison.  It shuts down the victim’s nervous system.  A victim may recover in a few hours or days or they may die from suffocation while wide awake as their lungs and heart cease to operate.

Banks, S.; and Anthony Pachee

“Biology and Fishing Data on Northern Puffer (Spheroides maculatus)

NOAA Report 26 1961

Gibbon, Euell

Stalking the Blue-eyed Scallop 

David Mackay Publishing 1964

Pleistocene Mockingbirds (Mimus polyglottos)

June 9, 2018

Mockingbirds are swingers.  Most suburban yards in southeastern North America host a pair of mated mockingbirds, but they might not remain the same pair throughout the breeding season because both males and females often switch mates.  Male mockingbirds sit on the top of trees and sing long melodious songs to attract female mockingbirds from adjacent territories, not unlike the way human pop singers attract groupies.  Female mockingbirds may leave their mates for better singers.  Males also flash their wings, and this entices female mockingbirds as well.  It doesn’t matter if a male already has a mate because they will continue to try and attract other females.  Constant mate switching ensures the genetic vigor of this species.  Despite this competition, mockingbirds from adjacent territories respond to their neighbor’s distress calls and will help drive away predators, such as crows.  Each territory of swinging and singing mockingbird mates can produce 2-4 broods per year.  Mockingbirds are an intelligent bird able to recognize individual humans, and they can imitate the calls of at least 14 other bird species as well as the vocalizations of cats, dogs, frogs, and crickets.

Photo of a mockingbird in my front yard.  Click to enlarge.

Northern Mockingbird-rangemap.gif

Northern mockingbird range.

I wonder how common mockingbirds were during the Pleistocene compared to today.  Studies show mockingbirds enjoy longer lives in suburban areas than they do in wilderness refuges.  Scientists believe mockingbirds prefer the stability of manmade habitats where they can find the same nesting sites, fruit trees, and insect species year after year.  They don’t have to travel far to find favorable habitat that might be dispersed in a wilderness.  I hypothesize mockingbirds were common in the south during most climate phases of the Pleistocene, but were not as common as they are today.  Mockingbirds probably occurred in forest edge habitat along megafauna trails maintained by the regular migration of herds.  Mockingbirds could rely on fruits originating from trees sprouting in seed-filled dung, and they fed on insects stirred up by roaming large animals.  Northern mockingbirds are uncommon in the fossil record.  They are known from just 3 specimens excavated from Reddick and 1 in Haile–both located in Florida.  Bahamian mockingbirds (M. gundlachii) left fossil evidence at the Banana Hole site in the Bahamas.  This paucity of fossil evidence doesn’t mean mockingbirds were an uncommon bird in the past.  Potential sites of fossil preservation in their favored forest edge habitat just didn’t exist to any great degree.

Genetic evidence does suggest mockingbirds have an ancient origin somewhere in South America where the most species of mockingbirds occur.  Mockingbirds belong to the Mimidae family which also includes thrashers and catbirds.  There are 14 species of mockingbirds: northern, tropical (M. gilvus), brown-backed (M. dorsalis), Bahama, long-tailed (M. longicauda), Patagonian (M. patagonicus), Chilean (M. thenca), white-banded (M. triuris), Socorro (M. graysonii), chalk-browed (M. saturninus), Floreana (M. trifusciatus), San Cristobal (M. melanotis), Hood (M. macdonaldi), and Galapagos (M. parvalus).  The northern mockingbird is a sister species to the tropical mockingbird, and they are so closely related they interbreed on the border region where their ranges overlap in southern Mexico.  The Chilean mockingbird is a sister species of the Patagonian mockingbird.  The uplift of the Andes mountains separated the founding population of these mockingbirds into 2 species.  Oddly enough, the Bahama mockingbird is a sister species to the 4 kinds of mockingbirds found on the Galapagos Islands including the San Cristobal, Galapagos, Hood, and Floreana.  Each of these species occupies just 1 or 2 Galapagos Islands.  Darwin wrongly assumed they were most closely related to South American species of mockingbirds due to the relative proximity.  But genetic evidence shows the mockingbirds that traveled over the Pacific Ocean to the Galapagos Islands came from even further away.  It seems likely this occurred before a land bridge connected North and South America.  Otherwise, the exhausted birds would’ve landed on Central America instead.  Unlike Darwin’s famous finches, mockingbirds didn’t evolve into different species that occupied different niches on each island, but instead remained habitat generalists, though each became a different species unique to the island they landed upon.

References:

Hoeck, P; et al

“Differentiation with Drift: A Spatio-Temporal Genetic Analysis of Galapagos Mockingbird Populations (Mimus spp.)”

Philosophical Transactions of the Royal Society of Biological Science 365 (1543) 2010

Lovette, I; et al

“Philogenetic Relationships of the Mockingbrids and Thrashers (Aves: Mimidae)”

Molecular Phylogenetics 2011

 

The Fear Island Special that Aired on Animal Planet Last Night was Full of Shit

June 4, 2018

The Animal Planet network has a history of airing misleading pseudo-science on many of their specials.  In their fake documentaries, researchers (usually actors posing as scientists) are on the hunt for creatures undiscovered by science.  In the past they have supposedly discovered evidence for mermaids and the continued existence of a long extinct shark species known as Carcharodon megalodon.  Last night, they aired a special culminating Monster Week entitled Fear Island.  A trio including a so-called scientist, a skeptic, and an Indian tracker were following a particularly large specimen of Kodiak bear.  The so-called scientist had a theory that Kodiak bears were either an hybrid between brown bears (Ursus arctos) X polar bears (Ursus maritimus) or an hybrid between brown bears X and an extinct species of bear from the Pleistocene (Arctodus simus).  They used camera traps and collected DNA samples from hair and feces to prove that this bear was an hybrid, and that it was 2600 pounds which would make it more than double the size of an ordinary Kodiak bear.  This gave the show a verisimilitude of real science, but it was not.

Image result for Fear Island on Animal Planet misleading

Don’t believe anything you see on Animal Planet.  They air unscientific bullshit.

There was a big problem with this special–scientists have already conducted many genetic studies of the Kodiak bear population.  Kodiak bears grow to more than double the size of the average mainland brown bear because of their diet…not because they are somehow a different species.  They enjoy an unusual abundance of salmon.  Genetic studies suggest Kodiak bears are the same species as the brown bear, and there is no admixture of polar bear in this population.  Moreover, the genetic studies indicate there is so little genetic difference between mainland brown bears and Kodiak bears that the latter should not even be considered a separate subspecies.  Nevertheless, at the end of the special Animal Planet claimed their genetic tests determined the Kodiak bear the hosts were following was a brown bear X polar bear hybrid, but tests to determine if there was giant short-faced bear DNA were inconclusive.  I promise, this supposed genetic test will never be subject to peer review in a real scientific journal because they were full of shit.  The giant short faced bear belonged to the Tremarctine group indigenous to the Americas, and these bears were separated from the Ursus bears by millions of years of evolution, making it highly unlikely that they ever interbred.  Plus, there is no genetic material of giant short-faced bears available for comparison.  So, of course, that finding would be inconclusive.

No way did the bear they were following weigh 2600 pounds as they estimated.  Any brown bear walking past a camera trap is going to look big, and I’m sure their estimate was badly miscalculated.  To prove it weighed that much, they would actually have to weigh it.

The Indian tracker told of an incident when 6 bears carried a dead bear to an hole they dug and buried it in a funeral like ceremony.  He told it with a straight face, but obviously he was pulling their leg.  Nevertheless, the so-called skeptic believed his story.  Don’t believe anything you see on Animal Planet.  This network lost its credibility a long time ago.

Tallow Plum (Ximenia americana) and Pre-historic Rafting Events

June 3, 2018

I posted the below photo on the Florida Flora and Systematics Facebook page, and the 2 plants in the picture were identified within about 5 minutes.  I saw this shrub and flower growing at Manatee State Park in Florida, while I was in the sunshine state visiting my sister and mother who recently moved there.  I joined that Facebook group because I am not as familiar with plants found in Florida as I am with Georgia’s flora.  I’ve read about tallow plum, but it was a big help for someone to help me identify it.

The flower in the foreground is Chapman’s pea (Chapmannia floridanus); the scrub bush in the background is tallow plum.

Tallow plum is in the Olalaceae family which includes olive, ash, and privet.  It produces an edible, waxy, sour fruit; and the tree reaches an height of 18 feet.  The tough plant thrives on sandy soils and can even grow on beaches, perhaps explaining its wide geographical distribution.  This species is found throughout most of Florida as well as the Caribbean, Central and South America, Africa, and Australia.  I wondered how it attained such a vast geographic distribution, but when I researched the species on google, I found no scientific studies delving into this mystery, and I learned no genomic wide studies of the Olalaceae family have been conducted yet.  I couldn’t even find any speculative discussions of its range, so the ancient history of this species has been overlooked.

I hypothesize tropical storms disbursed this species on rafts of vegetation to different continents near the equator.  Hurricanes can wash plant material far out to sea, and when it lands on a different continent, surviving flora and fauna can then colonize new territory.  (Animals often cling to these rafts of vegetation.) This hypothesis has also been proposed to explain how monkeys and rodents originating from Africa colonized South America, and it is the commonly accepted explanation for how anole lizards conquered Caribbean Islands and southeastern North America.  The ability of tallow plum to grow on sandy soils helped them set roots on beaches when they made landfall, following severe storms and currents that carried them halfway around the world.  Uprooted plants must have been able to survive for weeks while floating on the ocean before reaching land where perhaps waves or river currents reburied the roots in soil.  Some soil likely clung to the floating uprooted plants, and timely rains helped keep the plants alive.

The only fossil site with specimens of tallow plant is of Pliocene-age, and it is found in Africa.  The site is estimated to be between 4.3 million years BP-3.8 million years BP.  The only other species of tallow plum (X. caffra) is also found in Africa.  It seems likely Africa is the continent of origin for tallow plums.  Geneticists could shed light on the evolutionary history and distribution of tallow plum, if they ever look at its genome.