Geographic Distribution of Living Species Body Structures Packet page 26 Fossil Record Geographic Distribution of Living Species Body Structures Similarities in Embryology Biochemical Evidence

shows evidence of how organisms have evolved over time Transitional fossils have been found which show intermediate stages of evolution of modern species from species now extinct

The fossil record is an “incomplete record” because: Not all fossils have been found Some fossils have decomposed Not all organisms left fossils

Species living in different places with similar environments have similar anatomies and behaviors, even though they are unrelated

They are exposed to similar pressures of natural selection so they evolve similar characteristics

Homologous: Structures that share the same origin and basic structure but have different functions Ex. Bat wing, whale fin, human arm

Analogous: structures that are not of common origin but have the same function Ex. Bird wings and insect wings

http://evolution.berkeley.edu/evolibrary/home.php

Structures that have no function in their present-day organism but resemble functional structures of other organisms.

- This suggests that the structures are inherited from a common ancestor. - Human coccyx is at the end of the spine and seems to the remnants of a tail. - Human appendix seems to have no apparent function (may have needed it in the past to digest food). - Whales & snakes contain pelvic bones just as humans do, but they serve no function.

Embryology The early stages, or embryos, of many animals with backbones are very similar.

During development, organisms may exhibit characteristics of other organisms. The human embryo exhibits characteristics of the embryos of its ancestors. Early in their development, embryos posses gill slits like those of fish. Later in development, the embryos develop a tail. Human fetuses have a fine fur (lanugo) during the fifth month of development

All organisms use DNA and RNA to transmit genetic information ATP is an energy carrier in all organisms.

Organisms with similar amino acid sequences or similar DNA fingerprints are believed to have a more recent common ancestor. Ex: The amino acid sequence for the protein hemoglobin in humans is very similar to the sequence in the Rhesus monkey. They differ by only eight amino acids. 24

The DNA fingerprint pattern will be very similar for organisms that share a more recent common ancestor.

Artificial Selection Artificial selection is the intentional reproduction of individuals in a population that have desirable traits

Artificial Selection in Agriculture