Evolution is a theory that argues that all organisms alive on earth today share a common ancestor. It is thought that through generations, specific changes or adaptations were established in species in order to help them survive, reproduce, and raise offspring. But how are we certain that these changes occurred? Before, life on Earth was driven by carbon dioxide not until oxygen became plentiful and underwater invertebrates slowly started to adapt it into their system. Through fossil records scientist have evidence that show how anatomical and physiological alterations occurred to species that caused them to turn from aquatic animals to terrestrial animals. The following are gradual changes that took place in species respiratory system, and will allow some underwater invertebrates to transform to land-dwelling vertebrates through evolution.
It is said that fish were amongst the first species to live on Earth. The first invertebrates on Earth were jawless fish that used gills to breathe underwater, which are capillary-filled flaps near the mouth. When water flows over the gills, the blood in the capillaries exchanges carbon dioxide for oxygen; a process known as gas exchange. Jawless fish are characterized by having a sucker-like mouth or filter feeder for eating and not having front or rear fins, so they used the “S” motion for swimming (Arreola, 2006). Arreola (2006) asserted that jawless fish were later wiped out and other fish appeared.
These new fish are now classified as vertebrates who belong to the phylum Chordata. At some point of their life they had a dorsal hollow nerve cord, a notochord, pharyngeal pouches, and a tail that extends beyond the anus. The development of the jaw was useful with the teeth and muscles, by...
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...parates species according to their common structure. Fossils show how tetrapod legs evolved from fins and genes studies show how mutation and natural selection resulted into long limb bones from the fins (Hoff). In this case, they have uncovered how a species that lives on water transitioned to a terrestrial way of life.
It took millions of years for evolution to generate certain animal adaptations. For example, gills became lungs, fins became legs, and bodies produced fur and took the familiar shape the animals we have on land today. Their internal and external characteristics adapted into their new way of life as environment changed. Perhaps descendants found land a source of abundant food and a haven from competition. These species had to evolve and change the way they previously would breath, ate, and reproduced in order to have better chances of survival.
Study done from the available fossils show that the body of Liopleurodon was very streamlined and adapted to swimming. Its body had four limbs which were paddle-like in shape. These paddle shaped limbs acted like propellers which made it
...nted muscles. The quadrupling of genes led to bigger animals such as elephants. The largest member of the chordate phylum that ever walked on Earth was dinosaurs. The closest animal relative to humans is great apes. Great apes can think, feel, nurture own kind, pass on social skills, mimic, and remember just like humans do. Human intelligence is greater than anything on Earth! This video enhanced my understanding on Chordates because it explains how some chordates are or are not vertebras and it showed how land animals evolved from fish. I always like to see different videos on how species originated, especially humans.
The background of this article gives information that is necessary to understand the experiment. The shape of the pelvic girdle is an appropriate predictor of both phylogeny and movement in terrestrial vertebrates. However, in marine vertebrates, the gravitational forces typically applied to terrestrial pelvic girdles are not there and therefore have little impact on the shape of the girdle. Pelvic girdles of fish are generally not attached to the vertebrae and primarily are used as a place for muscles to attach and supporting of the fins. The authors discuss how in many cases the pelvic girdle could be removed and not result in any complications. However, there are some marine vertebrates that are capable of bottom walking on the ocean floor with their fins. In batoids, the pelvic fins are used for walking, which is when pelvic fins move in an alternating fashion, or punting, when both pelvic fins move at the same time. There is also augmented punting; this is when the vertebrate uses both the pectoral fins and the pelvic fins to generate more thrust, this action decreases the forces on the pelvic fins during a punt. While this locomotion would
comes from and how they evolved in the manner that they did. This type of
The main arguments in Evolution is the theory of natural selection, radiometric dating, and adaptation. The four parts to the theory of natural selection are that more individuals are produced each generation that can survive, phenotypic variation exists among individuals and the variation is heritable, those individuals with heritable traits better suited to the environment will survive, when reproductive isolation occurs new species will form. In simpler terms, this means that the organisms that are better suited to their environment will survive, animals have different genes and these genes change and can be inherited, and when one species is separated into two physically blocked areas, they will form new species. Radiometric dating as stated by Dr. Roger C. Wiens is “the process of determining the age of rocks from the decay of their radioactive elements”. This works through something called the half life of radioactive materials. The half life of radioactive materials is the amount of time it takes for radioactivity to fall to half of its original value. In simple terms, they measure how much a radioactive material has decayed and they get the age from that. Adaptation is similar to one of the four parts of natural selection. Adaptation of organisms is the variation among individuals in a species. The change from the parents to the offspring to better fit their ecological zone, is adaptation. Those are the three major facts that prove
What is evolution? Evolution in modern terms is fairly easy to understand. Evolution is the theory that life on earth began with a single celled organism that lived more that 3.5 billion years ago that slowly evolved into many diverse creatures over time. When you break down this theory into sections you get 6 factors: evolution, gradualism, speciation, common ancestry, natural selection and nonselective mechanisms of evolutionary change.
Evolution in general, is a hard concept to grasp. There are multiple factors that effect the outcome a species, for example: genetics, nurture, nature, and the environment all play an important role. It was once said that species do not survive due to the fact that they are the strongest or the most intelligent, but because that species is the most responsive to change.
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.
What is evolution and how does it work? Evolution is the theory of how one form of life changes into another form. Evolution also is the change in a population’s inherited traits from generation to generation. Evolution helps to explain why an animal, human, and plant looks the way it does and acts the way it does; it gives an explanation of the history of life. Genes come in many varieties, and the evolution helps to make it happen.
Acanthostega had a fish-like tail and gills for breathing under water, this being the aquatic part of it. But at the ends of the arms were “peddle-shaped” appendages, thought to be the first “hands” on Earth. Clack’s discovery proved that some fish had arms and legs in the water. It showed that arms and legs were already evolved before organisms started actually living on land, they were used more for survival than walking. In a sense, the “blueprints” of an arm were already in place.
The DNA code, that forms our genes, was the missing key for Darwin to understand how things evolved. DNA does not stay the same, it can be changed by mutations. Mutations are needed to generate variations. Without the mutations things would stay the same generation after generation. Pieces of DNA called a switch can turn certain genes on or off. Genetic Switches helps to create mutations which are sometimes responsible for an entire new species spawning from another. This is how a snake can evolve from a four legged animal, and how a whale 's front flippers has bones inside that resembles
To achieve the ability to such extreme transformation, the puffer fish came through the major evolution of its internal skeleton. Ribs and pelvic part of girdle have been lost and other parts of girdle have been modified to enable the pumping mechanism.
Sensory systems are essential to a mammal’s survival and for providing important information concerning their internal and external environment (Hill et al., 2011). Sensory systems depend on specialized sensory receptor cells that respond to stimuli, either from the mammals’ internal or external environment (2011). One form of sensory is electroreception, which is the detection of electrical currents or fields in aquatic mammals and mechanoreceptors are specialized to respond to different types of mechanical stimuli, such as touch, taste, smell, etc. (2011). The platypus (Ornithorhynchus anatinus) exhibits electroreception with the help of mechanoreceptors to detect prey item while submerged in water.
When these alterations are helpful, they grow to be fixed in a population and can result in the evolution of new phyla. Evo-devo seeks to figure out how new groups happen by understanding how the method of development has evolved in different lineages. In other word, evo-devo explains the interaction between phenotype and genotype (Hall, 2007). Explanation of morphological novelty of evolutionary origins is one of the middle challenges in current evolutionary biology, and is intertwined with energetic discussion regarding how to connect developmental biology to standard perspectives from the theory of evolution (Laubichler, 2010). A large amount of theoretical and experiential effort is being devoted to novelties that have challenged biologists for more than one hundred years, for instance, the basis of fins in fish, the fin-to-limb change and the evolution of feathers.
The world we live in today is full of an exceptional variety of animals. The time it took to conclude to the various sorts of species seen today has been throughout a period of millions of years. The vast majority of these animals are accredited to evolutionary advancements. When the environment changes, organisms have become accustomed to changing to fit their environment, to ensure their species does not die off. These physical changes have resulted in different phyla, ranging from basic structures, like sponges to advance systems, like that of an octopus.