Evolutionary Bio: EXAM 1

What is Uniformitarian?

What is Uniformitarian?

geological phenomena were the products of natural forces operating over time in total consistency

“Nothing in biology makes sense except in the light of evolution” -who said this statement?

Dobzhansky 1973

• Concerned with observation and classification of facts and the establishment of verifiable general laws and scientific theories

• follows basic principles of logic, critical thinking, and standard procedures.

• produces highly probable explanations from information at hand

Science

1. Problem is recognized

2. Research Question established

3. Hypotheses are developed and can be tested

4. An Experiment can be designed

5. Results support or deny hypothesis or other methodologies are preformed.

6. If all tests result in data that seem to be consistent with the initial hypothesis, and all tests fail to falsify it, then it gains in credibility and stature

Steps of Scientific Method

The search for generality is

one of the major goals of the Scientific method

Observation that has been repeatedly confirmed is a

Fact

Descriptive generalization about how some aspect of the natural world behaves under certain circumstances is a

Law

• Testable statement about the natural world that can be used to build more complex inferences and explanations

• explains why something occurs

Hypothesis

Well-substantiated, explanation of some aspect of the natural world that can incorporate facts, laws, inferences, and tested hypotheses.

Theory

• a statement of an order

• Description of what always occurs or relationship between what causes the occurrences every time.

Scientific Law

• a conception, proposition of formula relating to the nature, action, cause, or origin of a phenomenon or group of phenomena, formed by deduction and generalization from facts.

• based on large amounts of data and presented as a cohesive argument that explains this data in a mechanistic manner

Scientific theory

What provides an explanation for how organic life forms undergo changes and pass them on to descendent organisms resulting in increasing diversity of life forms

Theory of evolution

Evolutionary history is composed of a

series of speciation events

What is Anagenesis?

character modification

What is Cladogenesis?

lineage splitting

What is the process of reasoning from a part to a whole or from particular instances to greater generalities?

Inductive logic

What process of reasoning from general cases to particular cases take observations and design specific tests in areas of science, or regarding certain questions in where we do not have all the data?

Deductive Logic

Induction has no place in the logic of science is who’s view?

Karl Poppers

What is Karl Popper’s 2 formulations of the problem with inductive logic?

• the first is the establishment of the truth of a theory by empirical evidence

• the justification of a preference for one theory over another is better supported by empirical evidence

What is genetically based, heritable change, in one or more characteristics in a population or species through time?

Evolution

What is change that occurs below the species level?

Microevolution

What is change that gives rise to a new species?

Macroevolution

Evolution occurs at the

species level

What are higher taxa?

sets of organisms above the species level in taxonomic hierarchy

What is Darwin’s definition of evolution?

All plants and animals reproduce in excess of the numbers that can actually survive, yet adult populations remain relatively constant

What person did Darwin marry and what was their previous relationship?

Susannah Wedgwood Darwin = 1st cousin

What occupation was Darwin originally trained for educationally ?

minister

What was the name of the ship that Darwin had his first voyage on?

Beagle

How old was Darwin when he set out on the Beagle?

22

How many years was Darwin on the Beagle voyage?

5 years

What geologist trained and mentored Darwin and formed uniformitarianism?

Charles Lyell

“An essay on the principle of population as it affects the future improvement of society.” Who wrote this article and caused Darwin to arrive at the conclusion that there is a struggle for existence= idea for natural selection?

Thomas Malthus

Who’s essay was sent to Darwin on some of his ideas before he published the origin?

Alfred Russell Wallace

When was the origin published?

1859

What is the Fixity of Species?

species are immutable and the existence of each species was a result of divine creation or God created everything just the way they are.

What is the Typological Species concept?

designate a single specimen that serves as a representation of the ideal form of the species

What is the transmutation of species concept?

as the environment changed so did the species, this caused the divergence which gave rise to the numerous forms of organisms observed

In 1809 who formed the concept of the transmutation?

Lamarck

What is Progressionism?

after each cataclysmic episode on the earth, life was created again but in a more advanced way

Who was the founder of comparative anatomy?

Georges Cuvier

What is Catastrophism?

explanation of the stratigraphic features of the earth that postulated sudden, violent, and drastic changes interspersed between long periods of stability through geologic history (Eiseley)

The difference between evolution and natural selection is:

evolution is a fact and natural selection is a theory

What did Lamarck conclude in his 2nd law of nature?

all changes that occur in an organism are persevered through the reproductive process in the descendents of those changed = the inheritance of acquired characteristics

What were major impacts on Darwin’s Thinking?

1. Lyell’s Principles of Geology 1830

2. Voyage of the Beagle

3. Malthus’s “An Essay on the Principle of Population” 1798

What was Darwin’s Natural Selection Theory?

Slight variations that benefit an individual in its struggle for existence enables it to survive longer and reproduce more successfully than others. Individuals with injurious variations perish

How does the modern theory of evolution differ from Darwin’s view?

1. origin of variation in a species

2. mechanisms that maintain variation

3. importance of geographic isolation in speciation process

4. Nature of the species

What were the two ways that Darwin thought natural selection only occurred in?

1. sexual selection

2. variability of the environment to which a population is exposed

What 2 paths were sexual selection thought to occur in?

1. male combat

2. courtship

What was Darwin’s major contribution to evolutionary thought?

the concept of natural selection, he provided a mechanism explanation for evolution

Variation within a species is caused by a :

mutation

What are Mendel’s Principles of Heredity?

1. Principle of segregation of unit characters

2. Principle of independent assortment

What is the Principle of segregation of unit characters?

characteristics of organisms are controlled by genes

What was Darwin’s model of speciation?

• no role for the process of geographic isolation

• species could no longer interbreed with one another once they changed

Geographic speciation is also referred to as:

allopatric speciation (Mayr)

Lynch (1989) estimated that ___ of speciation events in vertebrates were consistent with a vicariant mode of speciation.

71%

What does it mean when relatively wide ranging species is fragmented by some external factor, while the 2 or more subsets of the single ancestral species are isolated from one another, and lineage independence among each of the subpopulations is attained?

vicariant speciation mode- one type of allopatric

What is the Principle of independent assortment?

genes within an organism recombine at random causing progeny to have the potential of exhibiting all possible combinations of genes

According to Darwin “Species” is a term given:

arbitrarily- Darwin didn’t believe that species existed since there were so many types of varieties

Dobzhansky( 1973) and Mayr(1963) contributed to the:

adoption of the biological species concept

What is the adoption of the biological species concept ?

stating that species are groups of actually interbreeding natural populations, which are reproductively isolated from other such groups

What 3 levels can fitness be measured in ?

1. the individual

2. the population

3. the genotype

What is Genetic Fitness?

the average contribution of one allele or genotype to the next generation or to succeeding generations, compared with that of other alleles or genotypes (Futuyma)

What is Fitness of an individual or population?

ability to leave viable progeny in relation to the ability of others (Dobzhansky 1962)

What is a gene?

composed of a set of nucleotide sequences that encode the amino acid sequence of an enzyme or other type of protein.

One gene codes for one:

polypeptide

Enzymes are composed of

1 or more polypeptide strands working in concert to achieve the catalysis of a given reaction

What is an allele?

1 of 2 or more alternative states of a gene

What is transcription?

first stage of gene expression in which mRNA is synthesized from a DNA template, initiated when RNA polymerase binds to a particular sequence of nucleotides on the coding DNA strand

What is translation?

second stage of gene expression, in which a polypeptide is synthesized by a ribosome using the sequence of nucleotides in the mRNA molecule to direct the order in which amino acids are added in the growing polypeptide chain

What is a mutation?

any change in the genetic message of a cell

What are point mutations?

alterations in the coding sequence of a gene that involves only one or a few nucleotides

What are two types of point mutations?

1. DNA Damage

2. Spontaneous mispairing

What are chromosomal rearrangements?

organization of the genetic message is changed

what are 3 types of chromosomal rearrangement ?

1. transposition

2. translocation

3. inversion

What is transposition?

process of individual genes move from one place to another on the chromosome which changes it’s expression or expression of neighboring genes

What is translocation?

process in which a segment of one chromosome becomes a part of another chromosome and contains more important effects on gene expression

What is inversion?

when the orientation of a portion of a chromosome becomes reversed and doesn’t usually effect gene expression but has an effect on recombination

What are 3 types of DNA Damage?

1. Ionizing Radiation

2. Ultraviolet radiation

3. Chemical Mutagens

What is Ionizing radiation?

X-rays and gamma rays that are highly mutagenic, absorbed by the water molecules it encounters, imparting energy on the electrons of their outer shell which ultimately leads to free radicals that are highly reactive and can break bonds in the DNA helix

What is ultraviolet radiation?

causes a crosslink pyrimidine dimer and if left unrepaired it can potentially block DNA replication.

What are Chemical Mutagens?

directly modifies DNA bases and alter their base pairing behavior

What is isomerization?

when nucleotides spontaneous shift to alternative conformations which can cause different types of hydrogen bonds, the polymerase will select the wrong nucleotide to pair if the conformation of the hydrogen is not correct

What is “slipped mispairing giving rise to deletion”?

sequence pairs may misalign looping out a portion of one strand, usually sequences will revert to correct alignment but sometimes the loops are excised resulting in a deletion ranging from a few to several 100 base pairs

What is a Frame shift mutation?

when slipped mispairing occurs in the middle of a codon

What is Polymorphism?

the condition of having more than a single allele at a locus

Plants are thought to be:

polymorphic at about 50% of their loci, with a mean of 1.96 alleles per locus

Animals in general are less

polymorphic than plants across loci studied

vertebrates have less ____ and _____ than invetebrates.

polymorphism and heterozygosity

What is monomorphic?

having only a single allele at a locus

What is Heterozygosity?

in a diploid organism, this is the condition of having 2 alternatives to the alleles present at a gene locus

How is Heterozygosity measured ?

1. estimating the average number of loci within a population of heterozygous

2. estimating the average number of individuals that are heterozygous for a particular gene locus

Gymnosperms

are cone bearing plants, pine cones

Which factor from gymnosperms would contribute to high levels of polymorphism?

wind pollination

How is a population genetically defined?

a spatially and temporarily restricted group of a conspecific interbreeding individuals and maintains a continuity over time because of reproductive interconnections between generations

What is a gene pool concept?

• all genetic information distributed among the individuals of an interbreeding group, and held as specific sets of genotypes each generation

• small isolated or semi-isolated colonies whose members can interbreed in a manner approximating panmixia

How are are zygotes or genotypes developed ?

results from the union of gametes produced by preceding generation

What is meiosis?

alleles are sorted and distributed to gametes. The gametes combine during fertilization to produce a new set of genotypes

What is panmixia?

random mating within a breeding population.

What does DEME mean ?

localized genetic populations

What is a modern definition of evolution?

the change in allele frequencies over time