Evidence for Evolution

1. Evidence for Evolution

2. 5 types of Evidence for Evolution • Palaeontology • Biogeography • Comparative Embryology • Comparative Anatomy • DNA sequencing (biochemistry)

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

4. 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.

5. 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.

6. 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

7. 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

8. 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.

9. 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.

10. 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

11. 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.

12. 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.

13. 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