Evidence of Evolution

Review:

1. Who wrote the Origin of Species? On what experience did he base his writings? Charles Darwin Galapagos

2. List some evidence that led Darwin to his idea of how species might change over time. Darwin’s Finches---beak sizes, Giant Tortoise---Different Shells Iguana---Marine

Evidence of Evolution:

1. Homologous and Analogous Structures

What does homologous mean? Similar features that originated in a shared ancestor

List examples of homologous structures.

Beaks, Forelimbs (wing/arm)

What does analogous mean? Structures with similar appearance and function but different embryological origins

List examples of analogous structures. Hummingbird Wing and Moth Wing

When trying to determine the evolutionary relationship between two species, would a biologist concentrate on homologous features or analogous features? Explain

Homologous Structures because they originated from a shared ancestor

2. Vestigial Structures- useful structures to an ancestor, but not useful in modern organisms

Examples: Tailbone, appendix

3. Similarities in Embryology

What is embryology? Science dealing with the formation, early growth, and development in organisms

4. Similarities in Macromolecules- more similar homologous proteins------the more closely related the species

Patterns of Evolution:

There are several ways that populations can change to adapt to their habitats. The pattern and speed of evolutionary change result from the changing requirements of the environment.

1. The changing of two or more species in close association with each other is called coevolution.

Ex. Predators - Prey

Parasites - Hosts

Plants and Animals - Pollination

2. Sometimes organisms that appear to be very similar due to similar adaptations are not closely related at all. This kind of similarity is the result of convergent evolution.

Ex. Shark (fish) Porpoise (mammal)

3. In divergent evolution, two or more related populations or species become more and more dissimilar. Divergence is nearly always a response to differing habitats and it can ultimately result in a new species.

Ex. Finches - adaptive radiation

Dogs - artificial selection

Review: