Evidence for Evolution

5 types of Evidence for Evolution Palaeontology Biogeography Comparative Embryology Comparative Anatomy DNA sequencing (biochemistry)

Paleontology In Palaeontology there is the study of: Fossils Transitional Forms

Fossils/ Transitional Forms The study of remnants or trace of a once living organism. It has discovered that: Certain species are older than others based on where the fossil is located The oldest sedimentary rocks contained no fossils Hard shells of plants and animals, allow us to date the age of rocks, date the age of other fossils Some species known in transitional form, have come from 2 or more different species which have interbred, offering the species more than 1 set of characteristics. E.g. The donkey and the horse mate to create a mule.

It supports the theory of Evolution by: Studying the remains of once living organisms, and their location which tells us about the age of rocks and different species Studying transitional forms where species come from 2 ancestral species. It helps us to understand that: The original species were soft species because no remains are found in the oldest rocks That species have evolved from more that one species mixed together Species were originally simple Species have become complex over time and developed hard parts.

Comparative Anatomy The study of the anatomy of species, comparing homologous structures and analogous structures. Homologous structures- Similar structures in the anatomy of species, however serve for a different purpose. E.g. – Pentadactyl limbs in human and bats. Analogous structures- Different structures in the anatomy of species, however serve for the same purpose. E.g. fins of fish, flippers of whales It has discovered that: The anatomy of different species is similar to that of another even though it may be used for a different purpose. All species have come from a common ancestor

It supports the theory of Evolution by: Studying the anatomy of species Drawing together conclusion by finding homologous/analogous structures It helps us understand that: Certain species are similar in anatomy Certain movements are similar however made with a different anatomical structure All species have evolved from a common ancestor

Biogeography The study of living things in relation to their geographical region. It has discovered that: -Species who live in the same environment and area, are similar to each other -This is due to the selective pressure of the environment, allowing the species which contain a certain characteristic to survive, and then become more common. -Species with similar characteristics were found in different biogeographically areas, which indicates that the continents were once joined together.

It supports the theory of Evolution by: Studying the similarities/differences between certain species coming from the same environment. Examining the relationship certain species have with the environment e.g. finding out why species survive/become extinct. These studies allow us to understand that: Some species survived while others didn’t due to environmental pressure That the continents were once linked, by observing similarity in species separated by sea. That mutations in species occurred and these mutated forms of the original species were able to survive in the environment.

Comparative Embryology The study of the embryos of different species and observing the similarities and differences between their embryonic structures. It has discovered that: All species are alike during the embryonic stage This leads to the inference that all species have come from a common ancestor

It supports the theory of Evolution by: Examining the similarities and differences between species during the embryonic stage. Examining the structure of the embryo of every species. It allows us to understand that: All species are very alike during the embryonic stage That certain characteristics distinguish different species from each other, however these are not prominent until a late stage of development. That all species have come from a common ancestor.

DNA sequencing The study in the field of biochemistry, comparing the DNA sequence of different species. It has discovered that: All species evolved from a common ancestor due to the similarities in their DNA Certain species have evolved from other species due to similarity.

It supports the theory of evolution by: Examining the similarities/differences in a species DNA in comparison to another. Working at a molecular level to distinguish origins of certain species and where they have evolved from Observing the number of differences in DNA over a period of time, creating an evolutionary tree. It helps us to understand that: Evolution begins at a molecular level, when the DNA of certain species becomes different to that of another's Species have originated from other species and belong to a certain family due to their DNA history