The process of direct breeding to produce offspring with desired traits, also referred to as selective breeding.
Ex. Pigeons produced with fan shaped tails.
Ex. Also used by humans to create new breeds of dogs as well as other species.
The process in nature by which, according to Darwin's theory of evolution, only the organisms best adapted to their environment tend to survive and transmit their genetic characteristics in increasing numbers to succeeding generations while those less adapted tend to be eliminated.The central theme of evolution.
All organisms must be equally adapted to their environment, which is a rare occurrence.
Cumulative changes in groups of organisms through time, originally proposed by Charles Darwin in his book, the origin of the species.
Newly evolved features, such as feathers, that do not appear in fossils of common ancestors.
Ex. Feathers in the species archaeopteryx.
More primitive features such as teeth and tails, that do appear in fossils of common ancestors.
Anatomically similar structures inherited from a common ancestor. Modifications of the ancestors body parts not entirely new parts.
Ex. Birds wings
Ex. Reptiles limbs
Structures that are reduced forms of functional structures in other organisms. Once a body part is no longer needed it will slowly become smaller until it will disappear.
Structure that has the same function but different construction and was not inherited by a common ancestor.
Ex. An eagle's wings compared to a beetles.
An early, pre birth, stage to an organisms's development. Vertebrate embryos exhibit homologous structure during certain phases of development, but become totally different structures in adult form.
An enzyme that is essential for respiration in highly conserved animals. Even though there are slight changes in the amino acid sequence, the molecule changes little over time.
The measure of the relative contribution that an individual trait makes to the next generation.
The evolved morphological adaptations that allow a species to blend in with their environment
The process in which one species evolves to look like another.
Ex. Western coral snake, California king snake
Hardy Weinberg principle
Showed mathematically that evolution will not occur in a population unless allelic frequencies are acted upon by forces that cause change. With the absences of these forces, the allelic frequency remains the same and evolution doesn't occur.
5 conditions have to occur for this principle to work
No genetic drift, no gene flow, no mutation,mating must be at random,and there must be no natural selection.
Any change in allelic frequencies in a population that results from chance.
The allele affected is chosen through independent assortment. Not as noticeable in large populations, but drastic in smaller ones.
The founder effect
An extreme example of genetic drift, results in a small population that settles in a location separated from the rest of the population.
A trait that is uncommon in the original population can be common in this population
Ex. Amish persons
Another extreme example of genetic drift, occurs when a population stoops to low numbers then rebounds.
The rebound gene pool is often genetically similar
A closed system, with no new genes entering the population, and no new genes leaving the population.
Non random mating
The belief that the mating process of organisms usually occurs in a close proximity, and can lead to inbreeding, and can lead to allelic proportions favoring homozygous individuals.
Helpful mutations throughout species
If a helpful mutation is selected, the trait is know to become more common, and continue to be passed from generation to generation.
The most common form of natural selection, operates to eliminate extreme expressions of a trait when the average expression leads to higher fitness.
Ex. Baby birth weight survival rate.
Increases the expression of an extreme trait in a population.
Ex. Peppered moth changes
See peppered moth survey sheet.
Ex. Galapagos finches.
Splits a population in to two groups. Tends to remove individuals with average traits and replace them with individuals with extreme traits at both ends of the continuum.
Ex. Various colors of snakes according to habitat
Change in frequency of a trait in order to attract a mate. Often occurs in populations in which males and females greatly differ.
Ex. Peacocks, peahens.
Prezygotic isolating mechanisms
Prevents gene flow throughout a population, operates before fertilization occurs.
Makes fertilization unlikely.prevent the genotype from entering the gene pool.
Ex. Eastern and western meadowlarks
Postzygotic isolating mechanisms
Prevent gene flow throughout a population, operates after fertilization has occurred to ensure that the resulting hybrid remains infertile.
Has occurred when a hybrid offspring cannot develop or reproduce.
A physical barrier between two similar organisms
Ex. Grand canyon separating Albert and kaibab species of squirrels.
A species that evolves into a new species without a physical barrier. The ancestor species as well as the new species live side by side during this process.
Ex. Apple maggot flies, appear to be diverging depending on which fruit they eat.
Ex. Plants mutated with polyploidy.
Also called divergent evolution, occurs when one species gives rise to many new species in response to the creation of a new habitat or other ecological opportunity. Occurs in a relatively short period of time
Ex. Cichlid fish in africa's Lake Victoria.
When the similarities between two species is so similar ones species evolution affects the other.
Ex. Comet orchids and moths which pollinate them.
When unrelated species evolve similar traits even though they live in separate parts of the world. Occurs in environments that are far apart but ecologically similar.
Ex. The mara and the English rabbit.
The scientific theory that evolutionary traits evolve gradually in small, gradual steps.
Some exceptions according to fossil record.
Attempts to explain abrupt transactions in the fossil record. Rapid spurts of genetic change cause a species to diverge quickly, these periods last longer depending on how drastic the change is.
One of the most active areas of evolutionary research today. The study of the question, does most evolution occur gradually or in short bursts?
Opposeable first digit
Either the thumb or big toe, most common among monkeys and other primates.
Allows for a strong grip.
Overlapping fields of vision. Caused by the occurrence of bony eye sockets, and the placing of the eyes in front of the face.
Active in the night. Common for these species to have black and white vision. Also, causes a decreased sense of smell. Also, the degree of binocular vision is increased.
The ability to have and maintain a flexible body. Useful for primates who swing tree to tree.
Common characteristics of a large brain
Fewer areas devoted to smell
More areas devoted to vision
Larger areas devoted to memory and coordination of arm and leg movement
Aloes for problem solving abilities, and well developed social behaviors.
Complex ways of communication
Primate reproductive rate
The rate at which primates reproduce ( obviously ) allows for increased learning ability in cultures. Birth is a much slower process with one infant being born at a time.
Also called the 'wet nosed primates.' one of the most basic classification groups. Identified by their large eyes and ears. Most are found in Madagascar and nearby islands.
Ex. The lemur
Another one of the most basic primate groups, also called ' the dry nosed primates.' much larger than the strepsirrhines. Have brains realitive to their body size. Likely diurnal.
Ex. Tarsiers, monkeys, apes, gorillas, chimpanzees, etc.
New world monkeys
Smallest group of unique monkeys. Include marmosets and tamarins. Neither species has an opposable first digit or fingernails. Also includes squirrel and spider monkeys, as well as capuchin monkeys. Some of these monkeys have opposable first digits, most are diurnal, and live in social bands.
Acts as a 5th limb to primates. Often used to grasp to trees or other objects, and to support the monkeys weight.
Old world monkeys
Similar to new world monkeys, in the fact that they are diurnal, and live in large social groups. However, old world monkeys are usually larger and have narrower noses. Spend more time on the ground, no prehensile tail, or no tail at all, and most have opposable first digits.
Includes two groups lesser and greater apes. Have longer arms than legs, barrel shaped chests, no tails, and flexible wrists.
The Asian gibbons and most of their relatives. Generally move from branch to branch swinging even though they have the ability to walk.
Includes the family of orangoutangs. Lives exclusively in Asia. Also includes the family of gorillas. The chimpanzees are socially, and physically most similar to humans. Also includes other hominins,
Human like primates that appear to be more closely related to present day humans. Larger brains than hominoids, also have a thinner and flatter face than hominoids. Hominins also have manual dexterity, and are bipedal.
Includes all non monkey anthropoids, gibbons, orangutans, chimpanzees, gorillas, and humans. The largest of the primates, excluding hominins their arms are longer than their legs. The best known fossil of a hominoid is the proconsul
The species where the first true bipedalism was discovered. Was a small, ape like creature that lived in eastern and southern Africa about 4.2 to 1 mya. Had human like joints and teeth. However, had ape like brains and jaws.
The genus that includes living and extinct humans.
Homo habilis, homo ergaster, homo erectus, homo neanderthalensis, and homo sapiens.
Evolved exclusively in Europe and Asia around 200,000 years ago, likely from homo erectus or homo intermediary. Were shorter yet had more muscle mass than humans do. Had similar brain size and sometimes larger brains. However, their brains were likely organized in different ways than modern humans. Lived near the end of the ice age, and even had a basic language.
The out of Africa hypothesis
First proposed by Christopher stringer and Peter Andrews of the British museum of natural history in 1988, humans first evolved from Africa, and then migrated to other parts of the world.
The first widely accept way of biological classification. Classified animals according to the presence of red blood, animals were further classified according to their habitats and morphology. Plants were classified by average size and structure.
Based on the study of morphology and the behavior of organisms. Similar to aristotle's system. The first classification system of taxonomy.
Ex. Organized birds into three separate groups.
A discipline of biology primarily concerned with identifying, naming, and classifying a certain species based on natural relationships
Taxonomy is included in a branch of biology called systematics, or the study of biological diversity with an emphasize on evolutionary history.
Another name for Linnaeus method, gives each organism a scientific name composing of two parts, the first part is the genus, and the second is the specific epithet, or specific name that identifies the species.
A classification system based on that of Linnaeus, but including evolutionary naming.
A group of species that are closely related to a common ancestor.
Ex. Ursus americanas, Ursus ursinus, Ursus thibetanus.
Hypothesized the theory of evolution,after his trip to the Galapagos islands. The theory is explained in his book 'the origin of the species.'
The preserved evidence of an organism. Mostly found in various rock layers, greatly supports the theory of evolution.
The amount of time it takes half of the original isotope to decay, is required in radio metric dating. The relative amount of radioactive isotope and its decay product must also be known.
Geologic time scale
The record of earths history . Major geological and biological events in earths history can be seen hare
Ex. Mass extinction kt boundary
The epoch in which ancestors of most modern animals diversified across the planet.
Where the majority of the earths iridium is found. Indicating that there was a meteorite impact that led to mass extinction.
Describes the movement of several large plates that make up the surface of the earth. Includes the theory of continental drift.
The idea that life arises from non life. The belief of how humans originated, until disproved in the 17th century by Francisco Redi.
Theory of biogenesis
States that living organisms can only come from living organisms. First proposed by Louis Pasteur.
States that ancestors of prokaryotic cells lived among the ancestors of eukaryotic cells. Proposed by Lynn Margulis.
Inherited features that are inherited among species.morphological or biochemical.
Ex. Eagles with hooked beaks.
A model used to compare DNA or amino acid sequences from two different species to estimate how long the species have been evolving since they divulged from a common ancestor.
A branching diagram that represents the proposed phylogeny or evolutionary history of a species or group.
More ancient than domain bacteria yet more closely related to eukaryotic bacteria. Very diverse, and most are heterotrophic. Can live in extreme environments.. Cell walls do not contain peptidoglycan, and they have some of the same proteins eukaryotes do.
Kingdom Protista and Protists
Organisms that can be unicellular, colonial, or multicellular. No organs. Classified into 3 broad groups, protozoans,algae, and euglenoids.
Kingdom fungi and fungus
Multicellular or unicellular organisms that absorb organic nutrients in the environment. The members of kingdom fungi lack the ability to move, also all fungi are dependent on hyphae.
Threadlike structures that make up a fungus. The fungus is dependent of these for growth, feeding, and reproduction.
Kingdom plantae and plants
The base of all terrestrial habitats. All plants are multicellular, and have cell walls composed of cellulose. Most plants are autotrophic because of photosynthesis, but there are a few such as the parasitic dodder extracts it's food from host plants through suckers.
Kingdom and animals
All animals are heterotrophic , multicellular eukaryotes. Organized into tissues, organs, then organ systems. Animals live on all terrains.