Evolution Definition: The process when the overall POPULATION change over time.

Natural Selection Definition: The process whereby organisms better adapted to their environment tend to survive and produce more offspring.

Adaptation A change or process of change by which an organism or species becomes better suited to its environment.

Evolution act at the level of POPULATION

Natural selection at the level of INDIVIDUAL

Mimicry Definition: The phenomenon whereby unprotected prey species gain protection from predators by mimicking toxic or other wise protect species.

Evolution People & Theories

Charles Darwin The Father of Evolution Born in 1809, England Sailed on the HMS Beagle During his voyage, he made observations that led him to his THEORY OF EVOLUTINON.

Darwin’s THEORY OF EVOLUTION: a scientific explanation for the diversity of life, by proposing how modern organism evolved from common ancestors.

This voyage lasted from 1831 to 1836.

The Galapagos Islands lie 500 miles west of Ecuador in the Pacific Ocean, directly on the equator. Many of Darwin’s conclusions were based on observations of wildlife in the Galapagos Islands. “Galapagos” means turtle.

Darwin called this… which means change in species over time After returning from the Galapagos and studying different types of plants & animals he collected during the voyage, Darwin concluded that organisms change over time….

Jean Lamarck French scientist, who in 1809 proposed a hypothesis for how organisms change over generations. believed that over the lifetime of an organism, physical features would increase or decrease in size because of either the use or disuse of the feature. changes would then be passed on to offspring, enabling species to change over time.

Lamarck had correctly identified that a change is a species is linked to an organism’s environmental condition.

Thomas Malthus Wrote an essay in 1798 that said if the human population grew unchecked, there wouldn’t be enough living space and food for everyone. Malthus said that the forces that controlled population growth included war, disease natural disasters and famine

Alfred Wegener Most well known for his Continental Drift hypothesis (1912), which led to the modern science of plate tectonics.

In 1910, upon examining a new map that included African and South American coastline research data, Alfred noticed that depth features for corresponding coastline contours of the two continents matched, but did not have time to think about it much until later, in 1911, when he read paleontological evidence of creatures existing on the two continents that could not possibly have crossed the vast ocean distances.

Macroevolution Refers to major evolutionary changes over time, the origin of new types of organisms from previously existing, but different, ancestral types. Examples of this would be fish descending from an invertebrate animal, or whales descending from a land mammal.

Microevolution Refers to varieties within a given type. Change happens within a group, but the descendant is clearly of the same type as the ancestor. This might better be called variation, or adaptation, but the changes are "horizontal" in effect, not "vertical." Changes might be accomplished by "natural selection," in which a trait within the present variety is selected as the best for a given set of conditions, or accomplished by "artificial selection," such as when dog breeders produce a new breed of dog.

Pinky- 1. Population Size Small population allows chance to take over.

Ring Finger: 2. Non- Random Mating Organisms choose mate based on physical features and location.

Middle Finger- 3. Mutation Mutation, change in a DNA/gene, can affect frequency of gene pool.

Pointer Finger- 4. Movement/Migration Gene flow: Movement of individual into an areal will change the gene frequency –Immigration: individuals moving into an area –Emigrate: individual moving out of an area

Thumb- 5. Adaptation Natural selection –Favors individuals with traits that are suitable for the environment (thumbs up) –Selects against individuals with traits that are unfit for the environment. (thumbs down)

Main Types of Selection Pressures Stabilizing Selection –Natural selection favors the average for population selected Directional Selection –Natural selection favors one extreme of the population for that trait –often happens when environment changes in a consistent way- e.g.climate gets colder. Disruptive Selection –Natural selection favors both extremes selected –Causes species to diverge

Artificial Selection The intentional breeding for certain traits, or combinations of traits, over others… this can lead to speciation. (Human induced) What types of traits are selected for?

Speciation: The formation of new and distinct species in the course of evolution WHAT IS SPECIATION?

Allopatric Speciation Definition: new species evolves as a result of geographic isolation TYPES OF SPECIATION

Sympatric Speciation Definition: new species evolves from single ancestor while living in same geographic niche (organism’s “place” in ecosystem) TYPES OF SPECIATION

Parapatric Speciation Definition: new species evolves as a result of partial geographic isolation as a result of occupying a new/different niche TYPES OF SPECIATION

Divergent Evolution Definition: new species evolves from a common ancestor TYPES OF EVOLUTION

Convergent Evolution Definition: unrelated species become similar as they adapt to similar environments TYPES OF EVOLUTION

Parallel Evolution Definition: development of a similar trait in related, but distinct, species descending from a common ancestor TYPES OF EVOLUTION

Coevolution Definition: influence of closely associated species on each other in their evolution TYPES OF EVOLUTION

Definition: structures present in different organisms that have the same function but are structurally different and have different origins ANALOGOUS STRUCTURES

Definition: structures present in different organisms that have the same underlying structure but may have different functions HOMOLOGOUS STRUCTURES

Prezygotic Isolation TYPES OF ISOLATION Definition: reproductive isolation preventing a zygote Example: geographic, behavioral, mechanical

Geographic Isolation When a population is divided into two or more smaller populations due to PHYSICAL BARRIERS. This can occur when rivers change course, mountains rise, continents drift, or organisms migrate. Example: Northern Spotted Owl and Mexican Spotted Owl

Behavioral Isolation Two species do not mate because of differences in courtship behavior. Example: Blue footed boobies (mating dance), birds (mating song), nocturnal versus diurnal

Postzygotic Isolation TYPES OF ISOLATION HorseDonkey Hybrid = Mule Can NOT reproduce Definition: reproductive isolation that occurs after two species have mated Example: hybrid mule offspring are infertile

Embryology Station- a science which is about the development of an embryo from the fertilization of the ovum to the fetus stage Sort the cards into their correct location in the chart then answer questions.

Embryology

Comparative Anatomy (Homologous structure) study of the body structures of different species of animals in order to understand the adaptive changes they have undergone Read and compare the anatomical structures of different species and answer the questions.

Molecular Biology- study of biology at a molecular level Compare the Hox gene sequences between different species and answer the questions.

Cladogram- a chart that shows an organism's evolutionary history Study the cladogram and answer the related questions.

Biogeography- study of geographical distribution of organisms

What is evolution? Definition: Change in the allele frequency of a population over time.

Allele Frequencies The amount of an allele in a population –“B” –“b”

How does a population change over time? Genetic Drift- Reduce genetic variation –When the allele frequencies of a population is changed due to randomness or chance. –Reduce genetic variation

How does a population change over time? Gene Flow –When alleles travel from one population to another population of the same species. - Migration

Genetic Drift vs. Gene Flow

Beetles Modeling Lab Objective: Observe how gene flow and genetic drift can affect the allele frequencies of a population.

Bottle Neck When a population’s size is reduced for at least one generation due to catastrophic event. Example: Northern elephant seal

Founder Effect Occurs when a new colony is started by a few members of the original population. Example: Polydactyl in Amish communities

Cladograms

Cladograms are used to… Organize organisms based on evolutionary relationships (phylogeny). In other words… who is related to who and where did we come from…

How are cladograms constructed? Organisms are grouped together based on their shared derived characteristics (trait modified from the ancestral trait).

What do you know? Using the cladogram, which animals have claws/nails? (Hint: 4) Which animals have fur/mammary glands? (Hint 2) To what is the chimp most closely related to?

Look at the cladogram at the right. What conclusions can be drawn about the relationship between humans and chimps? Image courtesy of

How to read a Cladogram This diagram shows a relationship between 4 relatives. These relatives share a common ancestor at the root of the tree. Note that this diagram is also a timeline. The older organism is at the bottom of the tree. The four descendents at the top of the tree are DIFFERENT species. This is called SPECIATION. Image courtesy of

Branches on the tree represent SPECIATION, the formation of a new species. The event that causes the speciation is shown as the fork of the “V”. Image courtesy of

Species B and C each have characteristics that are unique only to them. But they also share some part of their history with species A. This shared history is the common ancestor. Image courtesy of

A CLADE is a group of organisms that come from a common ancestor. If you cut a branch of the tree, you could remove all the organisms that make up a CLADE. Image courtesy of