John Herron Shields Biology Period 2 21 March 2016 Land Mammals to Whales and Dolphins Recent evidence suggests that whales may not have always inhabited the oceans. Bones of an ancient ancestor of modern day whales, the Basilosaurus, were discovered in Pakistan that suggest whales evolved from a wolf-like creature. This genus of an early whale lived 34-40 million years ago in the late Eocene. These fossils show many different features in common with both modern day whales and modern day land mammals. Since the discovery of these bones, many other evidences show that whales are a likely descendant of the Basilosaurus through many different ways, such as embryologic comparison and DNA testing. Whales aren’t the only suspected descendants
Historically, the set of common characteristics among primates have been documented as a consequence of adapting to arboreal living (living in trees). Even though others placental mammals (a very diverse group of close to 4,000 species ranging everything from rodents/bats to humans) were able to adapt to various environments; such as living on land (ground-dwelling) to living in oceans (marine environments), while the primates found their adaptive niche in the trees (the place in which they survival dependent upon such as in terms of proving refugee, their source of food, its habitat, etc.). In addition, the primates were not the only ones who were able to adapt to living in the trees, other mammals were capable of adapting to this way of living, however, the majority of them continued to dependent on the land for their primary source of food. On
The Evolution of Whales The origin of modern day whales, a mystery that has puzzled paleontologists for years, may have just been solved with the discovery of an ankle bone. This discovery might sound simple and unimportant, but the bones of these ancient animals hold many unanswered questions and provide solid proof of origin and behavior. The relationship between whales and other animals has proven to be difficult because whales are warm-blooded, like humans, yet they live in the sea. The fact that they are warm-blooded suggests that they are related to some type of land animal. However, the questions of exactly which animal, and how whales evolved from land to water, have remained unanswered until now.
Previous research, which is almost entirely fossil-based, concludes mammoth mitochondrial DNA can be sorted into 5 haplogroups or 3 major clades. This hypothesis is correct however up until this study was published the timing of the clade evolution of the order in which they evolved was not known.
Dolphins are found to be directly related to wales and porpoises. Fossil evidence has been found from the second epoch of the Tertiary period that indicates early dolphins were already aquatic 45-50 million years ago. Scientists believe that animals that spent a great deal of time hunting for food around water areas may have through an amphibious stage before becoming solely committed to the water. Through changes in their teeth, scientists were also able to deduce that true cetaceans developed several millions of years after they took to the seas.
Whenever people look around at God’s miraculous creation, the variety of animals is astounding. There are 5,416 different mammal species. Each mammal was created with a special purpose and way of living. All mammals share similar characteristics, including being warm-blooded, having a skeleton, growing hair, producing milk, and birthing live offspring. Despite sharing these characteristics, mammals differ in size, shape, and habitat. The smallest mammal, the shrew and the largest mammal, the blue whale still have similarities despite their vast size differences. Because there are so many various mammal species, their small differences are used to categorize the mammals into separate mammal orders. Artiodactyla is one out of the 26 mammal
Fossils are considered to be evolutionary markers that records a lineages of creatures across time — providing a distinct way to compare different species. When Darwin set forth on a journey to the Galapagos Islands, he discovered many aspects of evolution. During his expedition, he discovered the fossils of creatures which closely resembled the modern armadillos. At that time, Darwin did not possess any tools or resources to predict the phylogenetic lineages and the evolutionary history of the armadillos. However, using modern day science and techniques like DNA and protein sequencing, it is now possible to better understand the relationships between different organisms. Furthermore, by observing the early developmental (embryonic) stages of a large mammal’s life cycles it is possible to indicate the relationship of the mammals with other mammals6. The combination of these methods may lead us to determine the phylogenetic position of armadillos Dasypodidae and other related organisms, such as anteaters and sloths.
Bottlenose dolphins are known to use sea sponges as tools when foraging for food in the ocean. This behavior is referred to as “sponging”. “Sponging” refers to when these particular dolphins put a sea sponge over their rostrum (snout area) and use it to help collect food. Different explanations have been given as to why Bottlenose Dolphins engage in this behavior. It has been perceived that young dolphins learn this behavior from their mothers. Researchers are also exploring the option that a differentiation in diving skills exists between dolphins caused by variation in the mitochondrial genes processing of proteins that are involved in the creation of the Bottlenose Dolphins’ respiratory system, and that variation may have lead them to
KERR, Tyler J., University of Wyoming, Laramie, WY, United States, 82071 BACKGROUND Whales (Cetacea) are unique among mammals in that they possess exceptionally dense, pachyosteosclerotic tympanic bullae1. Along the margin of the bulla is a highly mineralized, extremely dense wall of bone called the involucrum that serves as a special adaptation to life in the sea and as a means to facilitate sound reception and directionality underwater2,3,4. Moreover, this cetacean synapomorphy plays an important role in distinguishing its members from the ancestral terrestrial artiodactyls from which whales diverged5. When cut into cross-sections, the involucral region of the tympanic bullae in many mysticete (baleen whale) lineages reveals three easily distinguishable ‘zones’ of concentric laminar growth. Here we hypothesize that these three distinct zones identified along the length of the tympanic bullae are capable of recording life history events during early development, when the cetacean tympanoperiotic region is known to be rapidly ossifying6. We propose that the innermost zone (1) represents rapid in utero growth, the intermediary zone (2) represents rapid birth and postnatal development, and the outermost zone (3), markedly thinner, represents slower, more lamellar development from weaning on through adulthood.
Francesca Taylor Essay 3 Rough Draft In 1923 a British-Indian scientist by the name of John Burdon Sanderson Haldane wrote a book in which he described what he thought were the six most important biological discoveries ever made. The last of the six discoveries, and perhaps the most controversial of them all,
The mammalian line of descent reaches back to over 300 million years. The ancient relatives of mammals were extremely different in terms of appearance from living mammals, and are often mistaken for reptiles (for example dinosaurs). In reality though, these relatives of mammals, called synapsids, are more like mammals than reptiles.
Mammals were that distinct group of species for whom DNA barcoding was proved to be successful first time and mostly human hair was used to test mammal primers[8, 53].The essential usage of DNA barcoding ranges from the evaluation of the central web for morphologically mysterious species including carnivores, in order to capture misidentified individuals using hair, skin, feathers and furthermore to reconsider critical descriptors in regards to food web framework[54-57]. Mitochondrial cytochrome c oxidase subunit 1 is particularly acknowledge as a standardized specie level barcoding region in animals . Mitochondrial genes are favored over nuclear genes in case of mammals because mitochondrial genes don’t have introns; they are
All mammals are animals, yet not all animals are mammals. There are numerous organisms on planet earth, biologist even estimated 5-100 million species living on our planet today. The mammalia class is the most complicated class and on the top of the food chain. Just because it is
The early Greek physicians-scientists Aristotle and Erasistratus were some of the first people to test on animals. Galen a Greek physician conducted animal experiments to advance the understanding of anatomy, physiology, pathology, and pharmacology. Ibn Zuhr a physician from the twelfth century tested surgical procedures on animals before performing them on human patients.
QUESTION #3 Vertebrates divide into many different groups, in particular my interest leans towards mammals, there are many different mammals they all come in different shapes and sizes. Mammals are animals who feed their young with milk which is produced by their mammary glands and unlike other animal’s mammals have hair