Theory of Evolution ....and everything else

How do scientists copy the DNA of living organisms?

-The first step in using the polymerase chain reaction method to copy a gene is to heat a piece of DNA, which separates the two strands. -Then,as the DNA cools, primers bind to the single strands. -Next, DNA polymerase starts copying the region between the primers. These copies can serve as templates to make still more copies

What do homologous structures and similarities in development suggest about the process of evolutionary change?

-Evolutionary theory explains the existence of anatomical homologies adapted to different purposes as the result of descent with modification from a common ancestor. -Similar patterns of embryological development provide further evidence that organisms have descended from a common ancestor.

polyploidy

-Having greater than 2 sets of chromosomes. -Can be induced in plants for agricultural purposes. -Chemicals are used to do this.

Which factors influence evolution?

-Variation -Inheritance -Selection -Time

What is the process of southern blotting?

1. Gel electrophoresis separates DNA fragments produced by restriction enzymes. 2.Bands on the gel are immobilized by blotting onto nitrocellulose paper. 3.Radioactive probes bind to fragments with complementary base sequences.

fossil

A preserved remnant or impression of an organism that lived in the past.

Southern blotting

A technique that enables specific nucleotide sequences to be detected in a sample of DNA. It involves gel electrophoresis of DNA molecules and their transfer to a membrane (blotting), followed by nucleic acid hybridization with a labeled probe.

What does evolutionary theory suggest about the unity and diversity of life?

According to the principle of common descent, all species--living and extinct--are united by descent from ancient common ancestors, and exhibit diversity due to natural selection and adaptations.

How can molecular biology be used to trace the process of evolution?

At the molecular level, overwhelming similarities in the genetic code of all organisms, along with clearly homologous molecules, provide evidence of common descent.

inheritance

Biological traits are encoded in DNA.

What techniques are used to study human DNA?

By using tools that can cut, separate, and then replicate the DNA base by base, scientists can now read the base sequences in DNA from any cell.

How did Lamarck propose that species evolve?

-Organisms could change during their lifetimes by selectively using or not using various part of their bodies. -He also suggested that individuals could pass these acquired traits on to their offspring enabling species to change over time.

What does recent research on the Galapagos finches show about natural selection?

-The Grants have documented that natural selection takes place in wild finch populations frequently, and sometimes rapidly. -The Grants' work shows that variation within a species increases a population's ability to adapt to, and survive, environmental change.

What were the goals of the human genome project, and what have we learned so far?

-The Human Genome Project was a 13-year, international effort with the main goals of sequencing all three billion base pairs of human DNA and identifying all human genes. -The Human Genome Project pinpointed genes and associated particular sequences in those genes with numerous diseases and disorders. -It also identified about three million locations where single-base DNA differences occur in humans.

shotgun sequencing

Cutting DNA into random fragments and then determining the sequence of bases in each fragment

GFP

Green fluorescent protein obtained from jellyfish and causes bacteria to glow under UV light. Used as an indicator for positive transformation.

phylogeny

History of organismal lineages as they change over time.

The struggle for existence

If all populations have the potential to produce more offspring that can survive, members of that population will compete for a finite supply of environmental resources.

How is inherited variation used in artificial selection?

In artificial selection, nature provides the inherited variations, and humans select those variants they find useful.

agrobacterium

Inserts a small DNA plasmid that produces tumors in a plant cell.

What was Malthus's view on population growth?

Malthus reasoned that if the human population grew unchecked, there wouldn't be enough living space and food for everyone.

Under what conditions does natural selection occur?

Natural selection occurs in any situation in which more individuals are born than can survive(the struggle for existence), natural heritable variation affects the ability to survive and reproduce(variation and adaptation), and fitness varies among individuals(differential reproductive success)

How does the geographic distribution of species today relate to their evolutionary history?

Patterns in the distribution of living and fossil species, combined with information from geology, tell us how modern organisms evolved from their ancestors.

What do you do with the DNA once it is cut?

Perform Gel Electrophoresis

variation

Physiological, anatomical, behavioral traits that result from RANDOM MUTATION.

artificial selection

Selection by humans for breeding of useful traits from the natural variation among different organisms.

deep time

The idea that our planet's history stretches back over a period of time so long that it is difficult for the human mind to imagine.

biotechnology

The process of manipulating organisms, cells or molecules to produce specific products or characteristics.

What did Hutton and Lyell conclude about Earth's history?

They concluded that earth is extremely old and that the processes that changed earth in the past are the same processes that operate in the present.

How do fossils help to document the descent of modern species from ancient ancestors?

Today, however, many recently discovered fossils form sequences that trace the evolution of modern species from extinct modern ancestors.

How can genes from one organism be inserted into another organism?

Transgenic organisms can be produced by the insertion of recombinant DNA into the genome of a host organism.

EcoRI

a restriction enzyme that specifically cuts DNA with sequence GAATTC and creates sticky ends

genomics

a study of whole genomes, including genes and their functions

DNA fingerprinting

analysis of DNA fragments that are unique to individuals. Used in forensics (crime scene analysis).

bioinformatics

application of mathematics and computer science to store, retrieve, and analyze biological data

fitness

how well an organism can survive and reproduce in its environment

variation and adaptation

individuals with certain types of inherited variation are better suited or adapted, to life in their environment than others

clone

member of a population of genetically identical cells produced from a single cell

gel electrophoresis

procedure used to separate and analyze DNA fragments by placing a mixture of DNA fragments at one end of a porous gel and applying an electrical voltage to the gel

natural selection

process by which organisms that are most suited to their environment survive and reproduce most successfully;also called survival of the fittest.

vestigial structures

remnant of a structure that may have had an important function in a species' ancestors, but has no clear function in the modern species.

homologous structures

similar structures that are shared by related species that have been inherited from a common ancestor

transgenic

term used to refer to an organism that contains genes from other organisms

biogeography

the study of past and present distribution of organisms

CD4 Receptor and CCR5

understanding mechanisms of HIV infection, resistance and the promise of prevention through a vaccine.

What three patterns of biodiversity did Darwin note?

-Darwin noticed that different, yet ecologically similar, animal species inhabited separated, but ecologically similar, habitats around the globe. -He also noticed that different, yet related species often occupied different habitats within a local area. -Darwin also noted that the fossil record included many extinct animals that were similar to, yet different from, living species.

selection

-Differential survival and reproduction -Individuals with particular traits are more likely to reproduce than others.

evolution

Change in a kind of organism over time; process by which modern organisms have descended from ancient organisms.

recombinant DNA

DNA produced by combining DNA from different sources

SNPs

DNA sequence variations that occur when only one single nucleotide in the genome sequence is altered.

What was Charles Darwin's contribution to science?

Darwin developed a theory of biological evolution that offered a scientific explanation for the unity and diversity of life, by proposing how modern organisms evolved through descent from common ancestors.

time

biological evolution occurs over time

analogous structures

body parts that share a common function but not structure

epigenetic

heritable changes in expression of a gene that changes phenotype but not the DNA itself... just changes in chromatin structure

adaptation

heritable characteristic that increases an organism's ability to survive and reproduce in an environment

restriction enzymes

enzyme that cuts DNA at a sequence of nucleotides