Evolution

Key Terms Adaptation - Evolution - Fossil - A trait that helps an organism survive and reproduce. The gradual change in a species over time. The preserved remains or traces of an organism that lived in the past.

Key Terms Natural Selection - Scientific Theory - Species - Variation - Individuals that are better adapted to their environment are more likely to survive. A well-tested concept that explains a wide range of observations. A group of similar organisms that can mate with each other and produce offspring. Any difference between individuals of the same species.

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. To practice building nests the booby picks up rocks and throw them in a pile.

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. There are no two same species on the different islands. They are herbivores and eat cactus and grasses on the islands. Lonesome Gorge (the last of his species.)

Galapagos land iguana (Conolophus subcristatus) Land Iguanas do not stay together. The males are very territorial. To scare things off the iguana nods his head up and down its head fast . To attract a mate the male shakes its head side to side.

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.

Flightless cormorant - (Phalacrocorax harrisi) The bird, when first arrived into the Galapagos, could fly. The bird did not need to fly because, it had no natural predators and there is an abundance of food in the water. To feed the birds go into the water and dive down to catch fish.

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.

Selective Breeding The process of selecting a few organisms with desired traits to serve as parents of the next generation. By repeatedly allowing only organisms with the desired traits to reproduce, the more desirable trait becomes common and highly favorable in the offspring. Darwin made connections between the practice of selective breeding and organism behavior in nature as evidence for his theory of evolution.

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

1. Overproduction 3. More offspring are born than can survive This creates competition between offspring. 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 A change in the environment can affect an organism’s ability to survive. The environmental change can gradually lead to selection. The Galapagos Islands are a prime example of how the environment can lead to the evolution of a species by natural selection.

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 https://www.youtube.com/watch?v=9VyrbG7FZ2Q

DNA – the more similar the sequences of the base pairs 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 http://www.pbs.org/wgbh/nova/evolution/guess-embryo.html

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.

Geologic Time Scale