The Chuckwallas and Evolutionary Research

The Beak of the Finch by Jonathan Weiner explores evolution through the most famous examples in history—the finches of the Galápagos Islands. Charles Darwin’s theory of natural selection and the process of evolution are applied directly to what scientists refer to as Darwin’s Finches. Weiner follows scientists Peter and Rosemary Grant as they study the finches in real time on the Galápagos. Years of previous work, study and data is collected and analyzed. Different species of animals are observed and explained throughout history. The Grants have one goal, and that is to find the origin of the species, how organisms first began. They find that it really is about the “survival of the

Opening the documentary with scenes of chimpanzees navigating the forest while wielding rudimentary spears is quite frightening. Often, it is thought that humans are the only species on Earth that can make and utilize tools (such as weapons), and that is largely attributed to humans' advanced bipedalism. However, chimps have begun to use stripped down branches that are then sharpened by their teeth to hunt and catch a variety of prey. This means that chimps took distinct steps to create a weapon and conduct a hunt, and that can be related to humans' early ancestors and their rudimentary ways of life. This has major implications for two reasons: the first being that chimps are advancing intellectually and possibly socially as they seem to organize

The Texas horned lizard, Phrynosoma cornutum, is a species in the lizard family, Phrynosomatidae, which has ten genera and a diverse group of over 125 different species (Hammerson 2007; Cossel Jr. 1997). Lizards in this family can be found in Mexico, Panama, most areas of the United States and parts of Canada (Heying 2003). Phrynosomatids range in a variety of forms, but are most commonly distinguished by their small size (less than 10 cm long), rough and keeled scales, spikes on their bodies, and the fusion of the sides of their teeth to the sides of their inner jawbones, known as pleurodont teeth (Heying 2003). The thirteen species in the horned lizard genus, Phrynosoma, can be identified more specifically by their flattened bodies

Two anoles on different islands can have similar traits as long as their ecological niches are similar, however geographic isolation was the cause to have 3 different species evolving. They might have evolved by having swam, floated on natural rafts, or the islands may have been connected at one point. Therefore, lizards on the same island are more closely related to each other than lizards that have similar body shapes and live in the same type of habitat. Lizards from the same island are more closely related to one another than to similar looking lizards from other islands. For example, a grass-bush anole from Puerto Rico is more related a trunk-ground anole also from Puerto Rico, than it is to a grass-bush anole from Hispaniola. This shows that the same type of anole lizards evolve independently on each of the islands. However, there was a point in time whereas the anole species from the four Caribbean islands all evolved from one common ancestor. The cladogram produced shows that species from separate islands and ecomorphs, for example the A. cybotes from Hispaniola and the A. occultus from Puerto Rico, are more closely related to each other than they are to L. carinatus, which belongs to a different genus of lizards. The DNA evidence gathered from anoles from the four islands is able to determine the ancestry of a single species that inhabited the Caribbean allowed for diversity of new species in the

The Bunostegos have knobbly growths on their skull and are the largest recognizable reptiles ever seen in the Pareiasaur group, which are plant eating creatures. The Bunostegos traveled a remote desert approximately 260 million years ago. The unusual reptile belongs to the Pareiasaur group, they thrived during the Permian period. The cow sized creature has been named Bunostegos, which means “Knobby roof”. Researchers supports the idea that there was a remote desert in the middle of Pangea with unusual animals. It is possible that the bony knobs on the skull of Pareiasaurs did not serve as a protective function, but were purely ornamental. The knobbly growths remarkably vary in size and shape between different species. The long period of isolation

There is a continuous, uncertain scientific argument among biologists with respect to the speciation of populaces: would they say they are the same species or two separate species? The argument in this paper is, whether the two “Western” Flycatcher populations, Cordilleran population and Pacific slope population are the same species or two separate species.

The Galapagos Tortoise has 15 subspecies, each fitted to the conditions on the different islands (“Tortoise (Galapagos)” 1). Five of these subspecies have now gone extinct (“Tortoise (Galapagos)” 1). Sometimes called Giant Tortoises, they can weigh between 250 to over 500 pounds (“Galápagos Tortoise”). Because they weigh so much, they often lie down to conserve energy (“Galápagos Tortoise”). Both these characteristics contribute to the tortoises’ lack of defense against predators like invasive species.

Rogers fails to address the actual definition of a species, which has not yet been plausible; the species concept is debated and overlapping. Rogers clearly states that he does not want to address this issue, only the issue of change within already defined species (p. 6). The definition of a species is context dependent, yet many scientists still attempt to define it in black and white. This debate, although extensive, is an interesting subject in which to gain a new perspective; there is no scientific doubt that species change, but the actual timing of speciation is an ongoing inquiry. The opinion of Alan Rogers would have made a reputable contribution to this debate.

Phrynosoma hernandesi is a species of lizard in the family Phrynosomatidae, and is a highly variable species. Characteristics such as colour, pattern, and size vary based on its geographical location. Short-horned lizards such as the Phrynosoma hernandesi, have settled all across North America, particularly in Saskatchewan and Alberta Canada as well as Montana, Utah, Colorado, Arizona, New Mexico. The Phrynosoma hernandesi favours the desert environment and generally resides in the semi-arid environments of North and Central America, much like a majority of short-horned lizards that have settled throughout Mexico and along northeastern Sonora, Chihuahua, and Durango.

al. 2004, (Agosta et. al. 2004) critique the article by stating that there was not sufficient information that was provided for the evidence to claim that the horned lizards were adapting. The points Agosta et. al. 2004 thought that Young et. al. addressed was “evidence that selection has occurred on the trait in question” (Young et. al. 2004). An example of this would be when Young et. al. talked about how the horned lizards with the shorter length were least favored by selection therefore lizards with longer horns would have greater fitness (Young et. al. 2004). On the other hand, according to Agosta et. al. claim that Young et. al. failed to present three major points. The three major points are the “existence of a functional explanation for putative fitness differences associated with the trait”, “evidence for heritability of phenotype differences corresponding to trait variation”, and “knowledge of phylogeny such that putative adaptations can be shown to have originated in selective regimes in which they are currently advantageous” (Agosta et. al. 2004). Agosta et. al. thought the young et. al. lacked the information to support whether the horned lizards had adapted to the shrikes (Agosta et. al.

An international team of Scientists have discovered a new lineage of extinct plankton feeding sharks called pseudomegachasma. These sharks are said to have inhabited the warm oceans of nearly 100 million years ago. From data of newly collected fossil teeth, it is found that this new lineage of extinct sharks is very similar to the modern-day plankton eating megamouth shark. Lead Author professor Kenshu Shimada also states that these sharks would have evolved independent of the four known modern-day planktivorous cartilaginous fishes. These consist of the megamouth shark, basking shark, whale sharks, and manta rays. This discovery of the new lineage of extinct vertebrates is what makes this article completely relevant to the topic of week fourteen.

Natural selection is one of the most famous term in science. It is the survival of the fittest and it is do or die. One of the first people that studied evolution is Jean-Baptiste Lamarck. He was born in 1744 and died in 1829. According to Lamarck, the fossil record indicated evolutionary changes in species over time. It was primitive to modern species and the first clear recognition of evolutionary change. He suggested that evolution acted with some sort of forethought, or that evolution “responded to a need”, which does not happen. He also suggested that evolutionary change required the inheritance of “acquired traits”, which also does not happen. The only correct theory that he gave was, a species becomes more perfect as time goes by. Evolution

In the Caribbean Sea, there are more than 700 islands, all have different sizes but have a similar environment, within these islands, and there are 150 species of lizards under the genus name of Anolis. These lizards are widely spread out over the islands in the Caribbean, these Anolis have similar habitat, niche, morphology, and behavior but they are not closely related, which this is defined as the ectomorph. This means we can found several different species living in the same environment, but they share different habitats, some of them live on the ground, on the grass and some live on different part of the tree, which they are spread out in different niches and hunt their food there. In addition, the scientist also found out even though,

There are many factors which influence evolution. Some examples are availability of food and the ability to adapt. How did evolution lead to the Saddle-backed shell tortoise being the only one on the Galápagos Islands? Two scientists propose their theories on evolution.

While on the Galápagos Islands, Darwin kept notebooks about all the species there, and he noticed the variety of tortoises on the island who were essential in explaining his theory of evolution. There are several species of tortoise present on the Galápagos Islands that are all very closely related, but slightly different. There are eleven presently surviving subspecies of Galápagos tortoises; furthermore, six of the eleven are found on different islands in the archipelago, and the other five are all found on a single island on five separate volcanoes with their own mini-ecosystems (PNAS). Although all of the species of Galápagos tortoise is different, they each have small differences that can include maximum adult size, shell shape, and the length of the neck and limbs. The tortoises of the islands are most closely related to the Chaco tortoises along the western coast of South America, and they most likely came to the Galápagos by “rafting” across the water (PNAS). Similar to the tortoises, Darwin observed that the Finches on the islands also had changed to match the environment. Spread among the islands were fourteen subspecies of finch whose