Answer:
Here's a better answer. I know its late though.
Explanation:
There are multiple lines of evidence that provide support for common ancestry and evolution; this would be homologous features of anatomy and embryology and fossil records.
In comparative anatomy, there are many similarities between species because all life is related. Homology is similarities seen because of the ancestry of features or genes in an organism. Similarities can show descent from common ancestors and similarities can be seen in body structures, development, and DNA. Homologous structures are similar traits found in two different species that are the result of having a common ancestor. These structures are similar but may have different functions. An example of this might be the homologous structures in the limbs of humans, cats, whales, and birds. And then there are analogous structures, which similarly is that the structure of different species are similar because the trait is advantageous, not because they are related. An example of this is sharks and dolphins having similar fins. Along with anatomy is Embryology. Different species can have similar embryos because they come from a common ancestor. They may start with the same developmental plan but change drastically as they grow up. An example of this is seen in the early stages of development between fish and chicken embryos.
Next up, the fossil record provides evidence that supports common ancestry and evolution. The fossil record provides us with visual evidence for evolution. The fossil record directly allows us to pinpoint if there are any similar structures amongst organisms and see if there are any vestigial structures from ancestors that remain in organisms that still roam today. The fossil record depicts evolutionary change over the past four billion years, which can be seen through transitional forms, increasing complexity of life, and geographical distribution. Transitional forms are fossils that show intermediate states between an ancestral species and its evolutionary descendants. Increasing complexity is seen as life on earth becomes more complex. That and geographic distribution which has been studied closely and found that the continents have moved over time and that the fossil record reflects this movement. Fossils of different animals can be found on different continents around the world due to continental drift.
