Evidence of evolution Ch.12 and Ch.13

Put this on the cover… Evolution – Change in the characteristics of a population (not individuals) from one generation to the next. Evolution is CHANGE OVER TIME!

Flap Titles Some Evidence of Evolution comes from: 1. Fossils / Biogeography 2. Homologies – Molecular / Embryology 3. Homologies - Anatomical Homologies:  Similar characteristics due to relatedness from common ancestors. (Put this definition with the second title)

Fossils Fossils –preserved remains of an organism. Provide a snapshot of the past and can show evolutionary change Fossils can be dated by noting their positions in layers of rocks, known as strata. Older fossils are at lower levels. Put this on the top of the inside of the first flap.

Fossils Transitional Forms - Fossils or organisms that show the intermediate states between an ancestral form and that of its descendants. Put this on the top of the inside of the first flap.

Fossils Fossils that share similar features with modern organisms may have a shared common ancestor. Put this on the top of the inside of the first flap.

Biogeography Biogeography: Study of the distribution of species in geographic space and through geological time. Can indicate common ancestry (if organisms are not separated by a geographic area) – descendants evolved adaptations that suited them for their new environments. Put this on the bottom of the inside of the first flap.

Biological molecules Scientists can look at nucleic acid sequences in DNA to find evidence of evolution, or amino acids in proteins. Organisms that are more closely related will have fewer differences in their amino acid sequences (or DNA). Put this on the top of the inside of the second flap.

Biological molecules Similarities in amino acid sequences can indicate common ancestry The more similar two organisms’ amino acid sequences are, the more closely related they are. Put this on the top of the inside of the second flap.

Biological molecules By comparing the bands on this DNA fingerprint, you can determine if two organisms are closely related. Put this on the top of the inside of the second flap.

Embryology Embryology is the study of the development of an embryo. An embryo is an organism in the early stages of growth and development. At some point all vertebrates (backbone) have a tail, buds, and pharyngeal pouches. Many scientists believe that embryonic development is evidence of evolution. Put this on the bottom of the inside of the second flap.

Anatomical and Physiological Similarities Homologous Structures - anatomical structures that share common ancestors. (same structure; different function) Put this on the top of the inside of the third flap.

Anatomical and Physiological Similarities Vestigial Structures – structures reduced in size or have a less important function in different organisms. May have been important in the Ancestor. Put this on the bottomof the inside of the second flap.

Divergent Evolution Two different species share the same ancestor but evolved differently over time due to adaptations to new environments. Organisms have homologous structures Put this on the back

Convergent Evolution Two different species do not share the same common ancestor, but look similar because they have adapted to similar environments Have analogous structures – similar structures that are not due to a common ancestor Put this on the back