Evolution Great Transformations PDF

Preview

Summary

This reflection summary is based on the article "Evolution Great Transformations" and the documentary movie. Written for Antro 1 class, week 4, spring 2021...

Description

Evolution: Great Transformations The emergence of whales Whales and dolphins are mammals that live in the water, but mammals originally live on land. Whales are a very interesting group of animals that have large complicated brains like we humans, the film even points out that whales are out to alter ego that dominates water. A rare archeological find in Pakistan and the Valley of Whales in the Sahara desert was the final clue in the question about the evolution of whales. Pelvis and a kneecap, even toes were all part of the whale skeleton that was found in the desert. This find signified that whales were once four-legged animals. Scientists now think that the earliest ancestor of whales was similar to the 50 million-yearold wolf-like mammal called Sinonyx. It was a predatory scavenger that lived and hunted along the shores of the ancient sea, its ancestors found water to be a source of food and escape from the competition. Over millions of years, its front legs became fins, rear legs disappeared, bodies lost fur and took on familiar streamlined shape. Since the first find called pakisetus the list of known transitional whales has increased. It now includes ambulocetus, Rodhocetus, dorudon, and basilosaurus. Gradual migration of nostrils to the top of the head as whales adapted to breathing in the water is another sign of evolution. Bones are not the only proof of whale evolution, it is also visible in the way the move. Even though whales look like fish, they don't swim like it. They swim by undulating their spine up and down in the same whale land mammals do while running. In one sense, evolution didn't invent anything new in mammals, it just tinkering with land mammals. What misconceptions about evolution does this film dispel and what new questions does it raise (give one for each)? This film makes a point that evolution is a simpler process than we once thought. Since there are so many forms of life, we used to believe that I took some sort of novel creations starting from scratch again, again and again. But we now

understand that evolution works with packets of information and produces different combinations without having to invent anything fundamentally new, but combining the set of old features. Animals resemble each other because they all use the same set of genes to build their bodies. A set of genes that came from one ancestor millions of years ago. So we can draw a conclusion, that if we trace back all the genes, they all lead to one ancestor. Our evolution as humans began when our ancestors came down from trees and began walking. But what if our ancestors haven't stood up? What if they have taken one different step on the path of becoming a human? One of the great misconceptions people have is that once our ancestors stood up it inevitably led to the evolution of homo sapiens, but evolution worked with us the way it did with all other animals through a series of small adaptations. Based on the article "Saltshakers Curse" and the film - Does evolution have a goal, is natural selection striving to make perfect structures, does natural selection ever reverse or fail? Evolutionary transition does not have a purpose in mind, and it does not depend exclusively on natural selection to determine its course. Evolution has no objectives. Natural selection and mutation are two factors that contribute to evolution. Natural selection occurs when species with advantageous traits are able to outcompete other organisms and thus pass on their advantageous traits to future generations. Mutation occurs when new genes are created at random, which may result in new traits. As a consequence, you can start with very basic rules and end up with a very complicated structure. Natural selection or evolution are irreversible processes. However, natural selection does not produce perfection; it is not all-powerful. You don't have to be flawless if the genes are "healthy enough" to produce offspring in the next generation. Only looking at the populations around us should demonstrate this: humans may have genes for genetic disorders, plants may not have the genes to survive a drought, and predators may not be able to catch their prey every time they are hungry. There is no such thing as a perfectly adapted population or organism....