Penny Higgins - Storyteller • Artist • Scientist
Combining Science and Joyful Creativity
What’s it about?
Recently, there has been great discussion about the extraction of proteins from fossils. This paper outlines various methods, and their strengths and weaknesses, for extracting proteins from ancient bones.Continue reading “Methods for Extracting Proteins from Fossils: Paleoproteomics – #365papers – 2018 – 38”
What’s it about?
Isotopes of oxygen and hydrogen from water can give us insights into the altitude at which that water fell to the ground as rain. Some of this water can become incorporated into volcanic glass (in ash), preserving the isotopic values of the original water.Continue reading “Using Glass to Estimate Altitude – #365papers – 2018 – 37”
What’s it about?
The first billion years or so of Earth’s existence was marked by repeated bombardment of the planet by various asteroids, and even planetessimals. It is thought that this bombardment would superheat the Earth’s surface and kill any life that may have started to develop there. This study shows that, while the heating was extreme, there were still places that were protected from life-killing heat.Continue reading “Did Bolide Bombardment Kill Life on Earth More Than Once? – #365papers – 2018 – 36”
What’s it about?
The Endangered Species Act exists to protect species from extinction. However, the means by which we define ‘species’ can affect what groups of organisms get this protection. The ‘textbook’ definition of species (populations of organisms that interbreed naturally and have living and fertile offspring) is what most people think of. This is known as the Biological Species Concept. But what about sub-species, or isolated populations of organisms (such as the Florida panther)?
Modern phylogenetics, including cladistics, allows species to be defined using molecular data and focuses more on dividing organisms into the smallest, distinct populations, which are likely to be reproductively isolated.Continue reading “How Definitions of Species Affect Conservation – #UREES270 – 2018”
What’s it about?
This paper contains a discussion of the mammalian paleontology at Fossil Butte National Monument, Wyoming. The authors examined and identified at least 46 species of fossil mammals from 29 localities within rocks of the Wasatch Formation at Fossil Butte. Using techniques of stratigraphy, the authors correlated all the localities in order from oldest to youngest. Further, they used the species present and clues from the rocks themselves to interpret the ancient environment in which the mammals lived.Continue reading “Fossil Mammals and the Rocks that Contain them at Fossil Butte, Wyoming – #UREES270 – 2018”
What’s it about?
The authors observed the decay to two very similar organisms: amphioxus (Branchiostoma), a chordate, and the ammocoete larva (Lampetra), a vertebrate. It was observed that the distinctive characters that distinguish vertebrates from other chordates very quickly decay after death, resulting in both amphioxus and the ammocoete appearing to be merely stem chordates. Continue reading “Why Can’t We Tell If a Chordate Is a Vertebrate in the Fossil Record? – #365papers – 2018 – 35”
What’s it about?
Modern horses have a single obvious hoof on each lef, which is representative of the third digit – equivalent to our middle finger. The fossil record shows that horses evolved from three-toed ancestors, which themselves evolved from four-toed ancestors, which even further back, came from five-toed ancestors.
In modern horses, the remnants of digits 2 and 4 (our index and ring fingers) are evident as tiny splint bones fused to the cannon bone (third metacarpal or metatarsal) of the leg. The authors use study of limbs of adult, full-term fetal, and early fetal horses. They trace the positions of nerves and blood vessels in the legs of horses, as well as consider the articulation between the horse’s toe bones and carpal-metacarpal joints to show that modern horses retain parts of all five of the original toes that their deep ancestors possessed.Continue reading “Horses Have Five Toes on Each Foot – #365papers – 2018 – 33”
Minot, 1890, The Mesoderm and the Coelom of Vertebrates: The American Naturalist, v. 24, p. 877-898.
What’s it about?
At the start of every vertebrate’s life, they are merely a ball of cells. Then a hollow ball (blastula). Then a ball that’s been punched in on one side (gastrula) with a hole (blastopore). At the gastrula stage, the early embryo is composed of two simple layers. On the outside is the ectoderm (sometimes called entoderm), and on the inside is the endoderm.
A third layer, called the mesoderm, arises in vertebrates and later opens to form the body cavity or coelom (pronounced SEA-lome). The coelom is the open space in which our organs essentially hang. Our stomach, intestines, bladder, heart, lungs, liver, pancreas, etc. are not embedded in our body walls, but float and move relatively freely in the coelom, with some connections (mesentaries) to the body wall to keep everything from falling to the bottom. It’s this arrangement that makes things like laparoscopic surgery possible.
Anyway… At the gastrula ‘hollow ball of cells’ stage of an embryo, somehow mesoderm forms between the ectoderm and the endoderm, then divides to form the coelom and the lining thereof.
This paper looks at embryos of many different vertebrates, from sharks to mammals, to explore the origins of the mesoderm and the coelom.Continue reading “Making The Vertebrate Body Cavity – #365papers – 2018 – 33”
What’s it about?
Some late Cretaceous-aged (AKA Maastrichtian) rocks from Romania contain fossilized soils (paleosols), dinosaur bones and teeth, and dinosaur eggshells. The authors use geochemical analysis, specifically stable isotope analysis, from all of these materials to build a fairly complete picture of what the region was like at the time that those dinosaurs were alive. What they found was that the environment was relatively warm and dry, and that the dinosaurs didn’t appear to utilize different parts of the habitat, but instead lived side-by-side.Continue reading “Interpreting Cretaceous Environments from Multiple Sources – #365papers – 2018 – 32”
What’s it about?
The Jehol Biota is a group of fossils that preserve some of the best examples of feathered dinosaurs available. The fossils come from several localities in the Sihetun area of the Liaoning Province of China. The authors here used three cores collected around the region, plus some study of outcrops, to investigate the relative ages and environments of different parts of the Liaoning Basin.Continue reading “Assigning Age and Environment to Fossil-Bearing Cretaceous Rocks – #UREES270 – 2018”
Penny Higgins - Storyteller • Artist • Scientist