Powerpoint concepts (Classes 1-6) Flashcards
what is evolution?
processes that change genetic characteristics and may result in different species
what is biodiversity?
an exploration of the different organisms in the tree of life
what are the 3 most basic organisms
bacteria,, archaea, and eukaryota
what is ecology?
how organisms interact with each other and the environment
what does it mean for something to be alive?
- must acquire and use energy
- must be made up of cells
- must process information
- must go through some sort of replication
- must undergo evolution
what are the 3 unifying ideas of science?
- cell theory
- the chromosome theory of inheritance
- the theory of evolution by natural selection
what is cell theory?
all organisms are made up of cells and all cells come from preexisting cells
what is the chromosome theory of inheritance?
genetic info is found in genes,, consists of DNA, genes consist of the specific segments that code for products in the cell
what is the theory of evolution by natural selection?
the idea that all organisms can have traits that are either more or less beneficial to them, and the selected traits can become more common in the population if they are selected
what is a theory?
an explanation for a broad class of observed phenomenon that is supported by a wide body of evidence
what are the two competing theories regarding cells?
- Cell theory
- Spontaneous generation theory
what is the spontaneous generation theory?
organisms arise spontaneously from nonliving materials
who is robert hooke?
(1600’s)wasthefirstpersontolookatcells
who is Anton van. Leeuwenhoek?
(16-1700’s) Built his own microscopes which were very powerful for the time and he was able to observe human blood cells
who were schleiden and Schwann
(1800’s) they proposed that all organisms are made up of cells
who was rudolph virchow?
(1850’s) He theorized that all cells arise from other cells,
who was Louis Pasteur?
decide to run an experiment to test Virchows theory. Conducted an experiment with cells and different shaped flasks. The flask with the open neck had cells in the broth, and the one with the swann neck only had cells in the neck portion of the flask but not the broth
- concluded that all cells must then arise from preexisting cells
what are the implications of cell theory?
Common ancestry, all single celled infividuals in a pop. are related, and all cells in a multicellular crgamism are from preexisting cells and are also related
where did the first cells come from?
chemical evolution
who were watson and crick
“found” the double helix shape of DNA
what is DNA made up of?
-varying sequences of 4 bases
- adenine, guanine, thymine, and cytosine
(at the groupchat)
why are base pairs important?
they allow DNA to be copied and they preserve the info encoded in DNA
how is DNA encoded?
- DNA codes for RNA
- RNA codes for proteins
what does RNA do?
RNA is a single strand of nucleic acids that carry DNA code and code for proteins
what is the step by step of coding for proteins?
DNA to mRNA, to Protein to Phenotype
what are the 2 fundamental nutritional needs for organisms?
- chemical energy (ATP)
- other molecules that can be used as building blocks for DNA, RNA, proteins, cell membranes, etc.
how did darwin explain how natural selection worked?
through fitness and adaptations
if certain heritable traits lead to increased success in producing offspring then…
these traits become more common in a population over time
what is it called when a populations characteristics change over time?
evolution
natural selection acts on… and evolution acts on…
individuals.. populations
what 2 conditions need to be met for natural selection to occur?
- individuals must vary in characteristics thatare heritable
- certain versions of these heritable traits help individuals reproduce more oftne
evolution occurs when….. variation leads to….
heritable….differential reproductive success
what was the idea of special creation?
the evolutionary idea of thought before the 1800’s
1. species are unrealted
2. earth is only 6000 years old
3. species are unchangeable because they are created by god and therefore perfect
4. there is great chain of being and some species are higher than others
what was platos main line of thinking?
typological thinking (GOD)
what was aristotles thinking?
hierarchy of nature( great chain of being)
who was john Baptiste Lamarck?
proposed the a theory of evolution that began to break down typological thinking
- believed life started with spontaneous generation, but that species were able to change and were always producing better species
what were some flaws of Lamarks theory?
- he believed in the theory of inheritance of acquired characteristics
what was darwin and wallaces theories?
theory of evolution by natural selection
- species were always changing
- all species are related
- variation is key
what did darwin study and where?
finches and tortoises in the galapagos
what did darwin propose about the finches
these different species had evolved from the same common ancestor and then colonized different islands which then formed their characteristics
who was Malthus?
an economist that darwin got a lot of his ideas from,, he created the idea of struggle for existence
who was alfred wallace?
working class naturalist that supported his studies by collecting for museums and wealthy collectors,, discovered the distinct line that seperated chinese and austrailian types of animals
what did the theory of evolution do that had not been done before?
- emphasized he importance of variation and population thinking
- compiled evidence that species change over time and share a common ancestry
- used geological data and field observation to propose a plausible mechanism for evolution
what are darwins 4 postulates?
- the traits of individuals within a population vary
- some of these traits are heritable
- in every generation more offspring are produced than can survive
- some individuals with certain heritavle traits are more likely to survive and reporduce
what were darwins conclusions
If certain heritable traits lead to increased success in producing offspring
traits become more common in the population
the population’s characteristics change over time
Modified species arise from ancestral species: DESCENT WITH MODIFICATION
what is population thinking?
thinking of populations and how they change as opposed to thinking about how individuals change
what does the theory of evolution by natural selecion predict?
- species change thiugh time
- species are all related by a common ancestruy
what is the evidence for change?
- geological record
- fossils
- extinct species
- homologies
-speciation
-internal consistency
-case studies like antibiotic resistance
what are the different phases of population growth?
lag: high birth high death,, slow pop growth
exponential: high births, slightly lower deaths, and very high growth
transitional: population overshoots K,, more deaths than births occur
stationary phase: the population cycles between overshoot and undershooting K
why is natural selection not perfect?
vestigial traits and silent mutations,, these are examples of mutations that do not help fitness
who are rosemary and peter grant
they studies the evolution of finches throughout a drought and studies how theones with the smaller beaks were more adapted to find food and those with larger beaks dies out becasue they could not get food
result: skinnier beaks became more common in the population
what was still unkown even after darwin wrote his book
- how traits could be inherited
- how new traits could arise
what was the original theory of how organisms inherited genes?
traits between the mother and father were blended together
what was though to happen to variation due to the blending inheritance theory?
it was thought that variation would decrease over time
who was gregor mendel?
a monk who worked on how to improve crops though selective breeding,, pea plant dude
how did gregor mendel perform his experiment?
since the pea plants self fertilized, gregor cut out one of the reproductive organs from each of the oea plants and fertilized them himself
what did mendel want to observe in his study?
- seed and pod shape
- flower color
stem length - in general just phenotypes of diffferent pea plants
what were the results of mendels experiemtn?
- mendel crossed two hybrids and they all came out the same phenotype as both of their parents
- but th F2 generation came out at a 3:1 ratio for pheno types
- thereore mendel concluded that genes must remain intat from generation to genreation rather than blending like the previously accpeted theory
what was the name for the theory that resulted from mendels experiment?
- the particulate inheritance thoery
- genes were like particles and they were inherited from genration to generation
what were mendels claims?
- peas have two copies of each gene and may have two different alleles of the gene
- genes are particles of inheritance that do not blend together
3/ each gamete contans one copy of each gene - males and females contribute equally to the genotype of their offspring
- some alleles are dominant to other alleles
why is mendel important to natural selection
until mendels findings were discovered, natural selection was not accepted
who were sutton and boveri and why were they mportant
they incorporate mendels principles into cytology,, they established that genes and alleles occur on chromosomes
general info about chromosomes and mutation
- two alleles are found on homologous pairs of chromosomes
- mendels principle of segregation is ue to the seperation of hol=mologous chromosomes when eggs and sperm are made
-this process of seperation is called meiosis
homologous chromosomes carry the same sequence of genes, but not sneccesarily the same :
alleles
how many pairs of homo chroms to humans have?
23 (not including sex)
what is the process of development from conception to adulthood?
-cells undergo meiosis to create more sex cells
- a haploid sperm and egg come together to create a diploid zygote
- the diploid zygote undergoes mitosis until it becomes fullt grown
who do mutations do?
- can be beneficial, negative, or benign
- procide a steady supply of genetic and phenotypic variation
what are exceptions to mendeld rules?
Incomplete dominance: A heterozygote that has an intermediate phenotype so both alleles are partially expressed
codominance: neither allele is dominant or recessive to the other so it carries both phenotypes (ex. a brown and white spotted cow)
what are the assumptions of HW
- no natural selection
- no genetic drift/small populations
- no gene flow
- no mutations
- no nonrandom mating
what are the 4 mechanisms of evolution?
- natural selection
- genetic drift
- gene flow
- mutation
basically the same as the opposite of the assumptions for HW but just no non random mating
what is genetic flow realy important for?
conservation biology
