Biology: Evolution Unit

All of the change that have transformed life over an immense time.

An inherited characteristic that improves an organism's ability to survive and reproduce in a particular environment.

The ship that Charles Darwin sailed around the world with.

Darwin's theory of species living on Earth today descended from earlier species.

The process by which individuals with inherited characteristics well-suited to the environment leave more offspring on average than do other individuals.

Preserved remains or markings left by organisms that lived in the past.

The collection of fossils recorded in rock layers over time.

Species that no longer exist, help scientists reconstruct the past.

Similar structures among related species.

Homologous structures that have a major function in one species but not in a related species.

A group of individuals of the same species living in the same area at the same time.

Differences among members of the same species.

The selective breeding of plants and animals to produce offspring with traits that humans value.

Consists of all the alleles, or different forms of genes, in all the individuals in a population.

A generation-to-generation change in the frequencies of alleles within a population.

Populations that do not undergo change in their genes pools are not presently evolving.

The exchange of genes with another population.

A change in a gene pool due to chance.

The contribution that an individual makes to the gene pool of the next generation compared to the contribution of other individuals.

Drugs that kill or slow the growth of bacteria.

Proposed that species evolved through inheritance of acquired characteristics. (use vs disuse)

Geologist who proposed that gradual and observable geologic processes such as erosion could explain the physical features of today's Earth.

Recognized that human populations can grow much faster than the rate at which supplies of food and other resources can be produced.

Studying fossils led to suggest that Earth might be much older than a few thousand years.

-Darwin was influenced by other early thinkers, including Lamarck, Lyell, and Malthus -Darwin was also influenced by his knowledge of artificial selection. -Wallace's paper on evolution confirmed Darwin's ideas.

Darwin found that species vary globally, locally, and over time.

-Different, yet ecologically similar, animal species inhabited separated, but ecological similar, habitats around the globe. -Modern organisms evolved over long periods of time through decent from common ancestors.

The fossil record contains collections of fossils recorded in rock layers over time. Examples of this are places such as Australia.

The distribution of organisms relates to evolution because the best traits of organisms are selected. Example: It's easy for an owl to spot a white mouse sitting on a dark rock. But it's very hard for an owl to spot a white mouse in the snow.

Similar structures among related species provide clues about evolution.

Molecular evidence can be used by comparing embryos of similar species and DNA sequences. The more similar the sequences, the more recently the species shared a common ancestor.

-More individuals are produced each generation that can survive. -Phenotypic variation exists among individuals and the variation is heritable. -Those individuals with heritable traits better suited to the environment will survive.

1.) Improvement of domesticated animals and plants by breeding individuals with desirable traits 2.) The fossil record that shows a clear relationship between living and extinct animals 3.) Homologous structures in different organisms that are dissimilar in form and function but that have underlying similar structures

The only difference between natural selection and artificial selection is whether the difference in reproductive success is driven by naturally occurring processes, or whether the selection is imposed by humans. Explore Evolution obscures this in two ways.

Most survivors of the first pesticide treatments were insects with genes that somehow enabled them to resist the chemical attack. Their offspring inherited the genes for pesticide resistance - the population underwent evolutionary change that resulted in adaption to a change in the chemical environment - presence of the pesticides

Gene pools consist of all the alleles in all the individuals that make up a population. The population's gene pool is where genetic variation - the raw materials of evolution - is stored. The process of meiosis and fertilization shuffle alleles within the gene pool and deal them out to offspring in fresh combinations.

Genetic drift is the change in the gene pool of a population due to chance. The smaller the population is, the more impact genetic drift has on that population.

Gene flow is the exchange of genes with another population. Gene flow occurs when fertile individuals or their gametes migrate between populations. Gene flow tends to reduce genetic differences between populations. If it is extensive enough, gene flow can eventually mix neighboring populations into a single population with a common gene pool.

Mutation is a change in an organism's DNA. If the mutation is carried by a gamete, the mutation enters the population's gene pool. Mutation plays a key role in evolution as the original source of the genetic variation that is the raw material for natural selection.

Natural selection contributes to changes in a gene pool because it is the process by which individuals with inherited characteristics well suited to the environment leave more offspring on average than do other individuals

Fitness is how an individual fits into an environment, meaning weather its features are beneficial or not for its surroundings. It is the contribution that an individual makes to the gene pool of the next generation compared to the contributions of other individuals.

For 30 years, the Grants and their students have been studying the finches on a isolated, uninhabited island. The islands small size and limited population of finches make it an excellent setting for studying natural selection. During wet years small seeds are so abundant that they eat only a few large seeds. But, during dry years large seeds make up a greater part of the bird's diet - and the birds with larger beaks have more success leading to more deaths. The surviving finches are more with those of larger beaks. The trend continues in the following generations. But during wet years, birds with small beaks eat the small seeds more efficiently than the larged beaked birds. The average beak size in the population is changed again. In summary: Finches beak size plays as a role of recent micro evolution.

Only homozygotes gave the disorder and heterozygotes are resistant to malaria. The people with the disorder commonly die as well as people who have malaria and are not resistant to it. Therefore, the people heterozygous for the sickle cell allele remain in the gene pool.

While the drugs kill most of the bacteria, the resistant bacteria multiply. They quickly become widespread in the population.

This concept defines a species as a population(s) whose members have the ability to breed with one another in nature and produce fertile offspring.

The origin of a new species.

Major evolutionary changes. -speciation -extinction of species -evolution of new features

The inability of different species to interbreed. Barriers of Interbreeding: -mating seasons -behaviors

Occurs when a population becomes separated from the rest of the species due to geographic change or movement to an isolated place. (event that leads to speciation)

When a population of a species evolve adaptations to a variety of different environments and form diverse new species.

A model that describes long periods of little change are broken down by shorter times of more rapid change.

The study of how organisms develop from fertilized eggs to fully formed organisms.

Finding the approximate age of a fossil due to its position in rock layers.

Finding the exact age of a fossil by using radiometric dating.

A method to determine the exact age of a fossil using the amount of radio active isotopes in the fossil.

The time it takes for 50% of the original sample to decay.

A scale that organizes Earth's history into time periods.

-Precambrian -Paleozoic -Mesozoic -Cenozoic

The movement of Earth's continents on large plates of crust.

An episode of great species loss.

A branch of biology that involves the identification, naming, and classification of species.

Domain Kingdom Phylum Class Order Family Genus Species

Developed the system of classification (taxonomic ranks)

Two-part name.

1.) To assign a universal name to each known species 2.) To organize the diversity of life

A diagram that shows the hypothesized evolutionary relationships.

A process in which unrelated species from similar environments have adaptations that seem very similar.

Structures which appear to have similar functions but evolved independently of each other and do not come from a recent common ancestor.

Homologous structures that do not occur outside a particular evolutionary branch (a clade) in a phylogentic tree.

Phyltogentic trees that specify the derived characters of clades, to show relationships among organisms.

The biological species concept basically describes how to define a species. This concept defines a species as a population(s) whose members have the ability to breed with one another in nature and produce fertile offspring.

Macro-evolution involves the evolution of large scaled changes (outside of the gene pool) where as micro-evolution refers to smaller evolutionary changes.

Habitat Isolation Temporal Isolation Behavioral Isolation Mechanical Isolation Gametic Isolation

The differences of habitats with the same area can prevent mating from occurring. Ex: water snake vs land snake

Differences of seasons and time of day may lead to mating prevention of certain species.

Altered behavior patterns can prevent species from mating. Ex: different mating calls made by birds

Physical structure can prevent mating.

Sperm of one species may not be able to fertilize sperm of another species.

Geographic isolation can lead to the separation of a species. After a certain amount of time, the separated species can evolve new features to better adapt to its new environment. This causes species diversity and eventually (after macro-evolution take its toll) a new species can form.

Allopatric Peripatric Parapatric Sympatric

When a barrier forms, dividing the original population into two different species.

When a new niche enters the population and becomes isolated from the rest of the group.

When a new niche enters the population, becoming adjacent to the rest of the species.

A change in a population resulting in the occurrence of several different forms or types of individuals among the members of a single species. (variation)

The same set of bones can form the fin of a fish, the wing of a bird, the foreleg and hoof of a horse, or the arm and hand of a human...(same bones, different sizes.)

An example of existing structures taking on new functions is the penguin wing: The flippers of penguins are another example of how natural selection can modify existing structures for different functions. Penguins are birds. The flippers they use to swim are actually modified wings.

Development biology helps biologist understand how species develop and whether certain species are similar or different. -finding common ancestors -understanding genes that control the development of an organism

Fossils can form in a process called fossilization: As the bone slowly decayed, water infused with minerals seeped into the bone and replaced the chemicals in the bone with rock-like minerals.

Continental drift and mass extinctions are both large scaled evolutionary changes on our planet in which is the definition of macro-evolution. Continental drift and mass extinctions are examples of macro-evolution.

The study of evolutionary and molecular biology is helping scientists place organisms in certain taxonomic groups. -studying homologous structures (evolutionary biology) -sequencing and comparing entire genomes (molecular biology_

There are three different types of domains in classifying organisms and five different types of kingdoms. The three domain system separates organisms based on modern molecular evidence where as the five kingdom system places all prokaryotes in a single kingdom and the eukaryotes in four other diverse kingdoms.