Evolutionary+Biology

__Heredity and Evolution/ Evolutionary Biology__ Lab #3 - Mitosis and MeiosisWhat are the processes of mitosis and meiosis? What are the differences between mitosis and meiosis? What is the percentage of crossing over that occurs between the centromere and the gene? Lab #8:  Population Genetics and Evolution. Summary: how natural selection can alter allelic frequencies in a population, the Hardy-Weinberg equation and its use in determining the frequency of alleles in a population, effects on allelic frequencies of selection against the homozygous recessive or other genotypes. · Natural selection may favor some genotypes so that certain characteristics become more common. · Any genotype will be influenced by the frequency if all criteria are met. Homozygous recessive is worked against because “a” has a smaller chance of appearing

__Summary:__ In biology, evolution is the change in the inherited traits of a population of organisms through successive generations. When a population splits into smaller groups, these groups evolve independently and develop into new species. Evolution may occur when there is variation of inherited traits within a population. The major sources of such variation are mutation, genetic recombonation and gene flow. This process has produced all the diversity of living organisms. Two processes are generally distinguished as common causes of evolution. One is natural selection, a process in which there is differential survival and/or reproduction of organisms that differ in one or more inherited traits. Another cause is genetic drift, a process in which there are random changes to the proportions of two or more inherited traits within a population.

The scientific study of evolution began in the mid-nineteenth century, when research into the fossil record and the diversity of living organisms convinced most scientists that species evolve. The mechanism driving these changes remained unclear until the theory of natural selection was independently proposed by Charles Darwin and Alfred Wallace.

__Vocabulary words and definitions__ **Adaptation**- the evolutionary process whereby a population becomes better suited to its habitat **Natural Selection** - the process by which traits become more or less common in a population due to consistent effects upon the survival or reproduction; certain alleles are more likey to be passed on that others **Gene drift-** change in allele frequencies due to random factors (some individuals don’t mate, causing some alleles to be lost, small population, ect.) **Gene flow-** the transfer of alleles of genes from one population to another **Mutations**- alters one allele to antoerh (chromosomal rearrangements, base-pair substitutions); usually harmful, but occasionally helpful **Allele frequencies**- is the proportion of all copies of a gene that is made up of a particular gene variant (allele). It is the number of copies of a particular allele divided by the number of copies of all alleles at the genetic place ( [|locus] ) in a [|population]
 * Biogeography;** distribution of plants and animals
 * Homologous Structures;** structures in different species derived from a common ancestor
 * Vestigial Structures;** homologous structures with no apparent function
 * Embryonic devolopment;** early in development ,cloosely related species resemble each other
 * Biological Species Concept-** individuals that can mate and produce a fertile offspring are of the same speices.
 * Prexygotic Barriers-** prevent fertilization before zygote
 * Postzygotic barriers-** prevent hybriid zygote from developing into a fertile adult
 * Allopatric Speciation-** reproductive isolation due to geographical barrier
 * Sympatric Speciation**- reproductive isolation occurs within the parent range
 * Gradualism-** changes accumuate slowly and steadily throughout the lifetime of a species
 * Punctuated Equilibrium-** changes occur abruptly during speciation, species doesn't change much thereafter
 * Allometric Growth**- Difference in relative growth rates of various parts of the body
 * Paedomrphosis**- adult form retains larval characteristics
 * Homeotic Genes**- control organization of body parts

__People and their experiments;__
 * Carolus Linnaeus-** Founded taxonomy- science of namming and classifying organisms
 * James Hutton-** Uniformitatianism- all Earth processes follow a gradual cycle of creation and destruction
 * Charles Lyell-** Revived uniformitatianism, while allowing the influence of occasional catastrophes
 * Jean Baptiste Lamarck-** Devised theory of evolution based on inheritance of acquired traits- those traits most used by an organism are passed on to offspring.
 * Charles Darwin** - at 22 Darwin wass the naturalist on "The Beagle" which set sail for South America. Darwin was to map S. America. He notices that extinct fossil species resemble living ones in the same area. Also, he notices the species on islands resembles those on mainland. 20 years after his expidition, Darwin published Origin of Species, revealing his findings and solidifying the theory of natural selection.
 * James Ussher-** calculates that Earth was created on October the 22 4004 BC at 3:00 PM based off of the bible.
 * Adam Wallace-** a biolgical scientist who sent his own ideas and theories on evlolution and natural selection before Origin of Species was printed.

Links for each scientist (in the order above) : [] [] [] [] [] [] []

Pictures! 