Evidence of Evolution

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by LGrochowski
Last updated 6 years ago

Evolutionary Biology

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Evidence of Evolution


The fossil record supports the theory of evolution because it shows a progression of organisms and similarities between others. It shows that some organisms that were once common are now extinct and that there ares similar organisms that are still alive. It shows that they are slowly adapting and changing to the environment and this supports evolution. Relative dating is another example of evidence. This supports this theory because it shows the different eras in the years throught the rocks. Scientists can then look at the fossils and the corrosponding dates and then compare it to a fossil of a different area to see an example of an adaptation. Numerical dating is different because it relies on the decay of radio active elements. It helps date the rocks

Homologous structures are structures that share a common orgin but serve different functions. This shows that organisms with similar structure evolved from a common ancestor. They result from divergent evolution meaning that they started out similar and now are very different. Analogus serve the same function but have a different anatomy to them. Vestigal organs are normally useless. They are still there . They adapted to not using them and this shows and example of evolution.

Fossil record


Another difficulty in comparing traits between species rests on the fact that homologous structures not present in the adult organism often do appear in some stage of embryonic development. In this way, the embryo serves as a microcosm for evolution, passing through many of the stages of evolution to produce the current state of the organism. Species that bear little resemblance in their adult form may have strikingly similar embryonic stages. For example, in humans, the embryo passes through a stage in which it has gill structures like those of the fish from which all terrestrial animals evolved. For a large portion of its development the human embryo also possesses a tail, much like those of our close primate relatives. This tail is usually reabsorbed before birth, but occasionally children are born with the ancestral structure intact. Tails and even gills could be considered homologous traits between humans and primates or humans and fish, even though they are not present in the adult organism.

The simplest and most powerful evidence is provided by phylogenetic reconstruction. Such reconstructions, especially when done using slowly evolving protein sequences, are often quite robust and can be used to reconstruct a great deal of the evolutionary history of organisms. Cladistics is a particular method of hypothesizing relationships among organisms. Like other methods, it has its own set of assumptions, procedures, and limitations.

Genes and chromosomes


Artificial selection demonstrates the diversity that can exist among organisms that share a relatively recent common ancestor. In artificial selection, one species is bred selectively at each generation, allowing only those organisms that exhibit desired characteristics to reproduce. These characteristics become increasingly well developed in successive generations. The selection process is termed "artificial" when human preferences or influences have a significant effect on the evolution of a particular population or species. Indeed, many evolutionary biologists view domestication as a type of natural selection and adaptive change that occurs as organisms are brought under the control of human beings.However, it is useful to distinguish between artificial selection that is unintentional or involves manipulating the environment only, and artificial selection that alter internal DNA sequences in the laboratory. Genetic manipulation in labs can be used to produce the same changes that could be attained by selective breeding faster by Cisgenesis.

The distribution of living things on the globe provides information about the past histories of both living things and the surface of the Earth. This evidence is consistent not just with the evolution of life, but also with the movement of continental plates around the world-otherwise known as plate tectonics.Fossils of marsupials have been found in the Antarctic as well as in South America and Australia. During the past few decades scientists have demonstrated that what is now called South America was part of a large land mass called Gondwana, which included Australia and Antarctica and before that they were part of a region called pangea where all the continents were connected. This explains why the animals are in different locations but are the same sprecies. But the small adaptations are a result from the biogeography.


Survival of the fittest


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