Evolution

Charles Darwin (1809 – 1882) was a naturalist who studied living organisms on a 5 year journey to places like the Galapagos Islands. On his journey he collected over 5,000 specimens and wrote over 2000 pages of observations.

Where are the Galapagos Islands? The Galapagos Islands are part of the South American Country Ecuador. The islands are about 600 miles off the coast. Map by: http://www.orientvisual.com/6inchforever/gallery/southamerica_map.gif

Who lives in the Galapagos Islands

BLUE FOOTED BOOBY Phylum: Chordata  Class: Aves  Order: Pelecaniformes  Family: Sulidae  Genus: Sula To get food the Blue Footed Booby dives head first in to the water and catches fish. The bird has bright blue feet . Their babies are born with grey feet and looks like a white puff ball. As they grow the booby’s feet get blue. To practice building nests the booby picks up rocks and throw them in a pile. To practice flying the bird goes to a rock and jumps with its wing spread out.

Galapagos Tortoises Kingdom Animalia Phylum Chordata Class Reptilia Order Testudines Family Testudinidae Genus Geochelone (1) Galapagos Tortoises are some of the largest tortoises in the world. They mostly live In the higher part of the Galapagos Islands. There are no two same species on the different islands. Every tortoise species on Galapagos has evolved differently depending on the island conditions. They are herbivores and eat cactus and grasses on the islands. Lonesome Gorge (the last of his species.)

Galapagos land iguana (Conolophus subcristatus) Unlike the Marine Iguana the Land Iguanas do not stay together. The males are very territorial and do not like when other animals come into their space. To scare things off the iguana nods his head up and down its head fast and angrily and this causes predators to leave. To attract a mate the male shakes its head side to side. A female will pick the male who is biggest and brightest .

Marine Iguana (Amblyrhynchus cristatus) Marine Iguanas are the only water going Iguana in the world. They feed off of the moss on the rocks under water. After swimming the iguanas lay together in a pile to keep warm. Also, because there is salt water in their body's they need to get it out. The shoot the water out their nose. The color of the iguanas changes form island to island. Some are darker some have red on them and some have grey spots.

Flightless cormorant - (Phalacrocorax harrisi) The flightless cormorant is said to have evolved down. The bird, when first arrived into the Galapagos, could fly. Over time its need to fly faded. The Flightless cormorant did not need to fly because, it had no natural predators and an abundance of food in the water. For these reasons, over time, the birds lost the ability to fly. To feed the birds go into the water and dive down to catch fish. To attract a mate the Flightless cormorant male performs a dance to get the attention of a female.

Theory of Evolution Darwin spent 20 years consulting with other scientists, gathering more information, and re-evaluating his observations from his trip on the Beagle before he developed his theory of evolution.

Natural Selection In 1858, Darwin proposed an explanation for how evolution could occur in nature. Evolution occurs by means of NATURAL SELECTION.

Natural selection is the process by which individuals that are better adapted to their environment are more likely to survive and reproduce than other members of the same species.

Factors Affecting the Process of Natural Selection Overproduction Variations Competition Environmental change Genes

More offspring are born than can survive 1. Overproduction More offspring are born than can survive 3.

2. Variations Offspring are born with differences

Lichen Biston betularia Peppered Moth

3. Competition Resources are limited so some variations enable individuals to better compete for food, shelter, and mates.

4. Those offspring with “helpful” variations are more likely to survive and will reproduce and pass on those helpful variations to their young.

5. Eventually more and more of the population will have those “helpful” variations after many generations.

6. Adaptations Those “helpful” variations that appear in a population that enable an organism to better survive.

What helps you succeed in staying alive?

7. Environmental Change An area that is cut off from each will cause organisms to become different over time.

8. GENES Variations can result from mutations as well as the shuffling of alleles that an offspring receives from its parents.

How exactly did the giraffe get a long neck?

Evidence of Evolution Homologous structures - Similar body structures that related species have inherited from common ancestor. Ex. Fins, flippers, legs

Vestigial Structures – structures that through time have lost their functioning. Ex. Appendix

DNA – the more similar the sequences on the DNA the more closely related we are. Ex. 99% the same as chimpanzees

Embryology – the study of early development Embryology – the study of early development. Organisms develop very similarly. Ex. Pig, chick, human embyros

The Fossil Record Fossils- preserves remains or traces of an organism that lived in the past. Found in Sedimentary rock because they are formed when an organism dies and is buried in muddy sediment. The Fossil Record has gaps because not everything becomes fossilized at death.

Fossil Dating Radioactive- elements used to determine the actual age of a fossil. Most accurate dating. Relative – fossils are dated based on the rock layer they are found. The lower the rock layer the older the fossil. Does not give you an exact year.

Geologic Time Scale