Evidence of Evolution

Evolution 1) Evolution is the change in the frequency of alleles in a population over time. Over generations theses changes lead to new types of organisms developed from preexisting types.

Galapagos Recent volcanic origin most of animal species on the Galápagos live nowhere else in world, but they resemble species living on South American mainland. 500 miles west of mainland

Unique species Show Campbell videos!!!

2. Observation #1: Variation Darwin’s finches Differences in beaks associated with eating different foods survival & reproduction of beneficial adaptations to foods available on islands Warbler finch Cactus finch Woodpecker finch Sharp-beaked finch Small insectivorous tree finch Small ground finch Warbler finch Large insectivorous tree finch Cactus eater Tree finches Medium ground finch Ground finches Insect eaters Seed eaters Vegetarian tree finch Large ground finch Bud eater

Correlation of species to food source Seed eaters Flower eaters Insect eaters

2. Observation #1: Variation Giant Tortoises Whoa, Turtles, too!

Observation #2: Fossil Record Mylodon (left) Giant ground sloth (extinct) Modern sloth (right)

The Distribution of Fossils 4) The fossil record shows that the types and distribution of organisms on Earth have changed over time.

The Fossil Record 5. When fossils are arranged in the order of their age, a continual series of change is seen, new changes being added at each stage.

Transitional Species (Fossils) 6) A transitional fossil is any fossil which gives us information about a transition from one species to another. 7) Fossils of transitional species show evidence of descent with modification (or that species have changed over time).

8) Natural selection is the mechanism for evolution. “How Evolution happens by Natural Selection”

8) Natural selection is the mechanism for evolution. “How Evolution happens by Natural Selection”

8) Natural selection is the mechanism for evolution. “How Evolution happens by Natural Selection”

8) Natural selection is the mechanism for evolution. “How Evolution happens by Natural Selection”

8. Natural Selection Overproduction: more offspring than available resources Genetic Variation: offspring have different traits (different gene combos) Struggle to Survive: compete for resources Differential Reproduction: survivors reproduce and pass on favored genes

Darwin’s Idea Descent with Modification 9) Descent with Modification is the idea that organisms can change over time through a process called Natural Selection. Darwin never wrote about how life originated but how it could evolve once it’s here.

10. Essence of Darwin’s ideas (1) Variation exists in natural populations (2) Many more offspring are born each season than can possibly survive to maturity (3) As a result, there is a struggle for existence - competition (4) Characteristics beneficial in the struggle for existence will tend to become more common in the population, changing the average characteristics of the population - adaptations (5) Over long periods of time, and given a steady input of new variation into a population, these processes lead to the emergence of new species

Other Evidence of evolution 11) Evidence of evolution can be found by comparing several kinds of data, including… the fossil record biogeography anatomy and development biological molecules Evolutionary theories are supported when several kinds of evidence support similar conclusions.

Biogeography 12) Biogeography, the study of the locations of organisms around the world and in time, it provides evidence of descent with modification.

Anatomy and Physiology 13) Homologous structures- similar body patterns in different species, shows common ancestry between these species.

Anatomy and Physiology 14) Analogous structures are similar in function but have different evolutionary origins (developed differently). Organisms with Analogous structures are not closely related, instead they have developed similar strategies for survival.

Anatomy and Physiology 15) Vestigial structures are structures that do not serve a purpose but did in the species’ past. A species with a vestigial structure probably shares ancestry with a species that has a functional form of the structure.

Anatomy and Physiology 16) Related species show similarities in embryological development.

Biological Molecules 17) Biological molecules such as RNA, DNA, and proteins are used by all living organisms, indicating a common evolutionary history. DNA  RNA  Proteins! All known organisms are based on the same fundamental biochemical organization: genetic information encoded as nucleic acid is transcribed into rRNA, then translated into proteins by ribosomes. Perhaps most tellingly, the genetic code (is the same for almost every organism, meaning that a piece of DNA in a bacterium codes for the same amino acid as in a human cell). In addition, ATP is used as energy currency by all life.

Reflection Summarize Darwin’s ideas in your own words and provide an example Make me proud!