Ch 22 Flashcards
Define Inheritance of acquired characteristics
Suggested by lammarck
-that Individuals develop their phenotype changes in response to environmental changes
-This phenotypic changes I’ve been passed on to their offspring
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Define phenotype
The detectable trait of an individual.
In inheritance of acquired characteristics phenotypic changes are passed on to offspring
What is Darwin’s theory of evolution?
Evolution occurs by natural selection
based Variation among individuals in a population
does not follow a linear progressive pattern and it states that individuals with certain traits produce more offspring than others without these
What was some evidence of change through time and descended from common ancestors
- Data on earths age
- Extinction in the fossil record
- Transitional features in the fossil record
- The presence of vestigial trait
- The change in populations that can be observed today
- The geographic proximity of closely related species
- The existence of genetic, developmental, And structural  homologies
- The formation of new species from pre-existing species that can be observed today
What is the fossil record
Consists of all the fossils that have been found on earth and described in the scientific literature
Define extinct
Species that no longer exist
Define vestigial traits
A vestigial trait in an organisms is a reduced or incompletely developed structure that has no or slight function
Is evidence that species change over time
Ex:
Define phylogenetic tree
A diagram that illustrates the ancestor - descendant relationships among taxa
homologies
Evidence of change over time
Define homology
Is a similarity that exists in species descended from a common ancestor
It can be recognized by :
- Genetic
- Developmental
- Structural 
Define developmental homology
Is similarity of an embryonic form or developmental processes that is due to inheritance from a common ancestor
Structural homology
Similarities in adult organism more structures that are due to inheritance from a common ancestor
Example: limbs 
What does genetic homologles cause?
Cause developmental homologies observed in embryos then developmental homologies lead to structural homologies
Speciation
Is a process that results in one species splitting into 2 or more descendant species
Internal consistencies
The observation that data from independent sources agree in supporting predictions made by a theory and is the most powerful evidence for any scientific theory
Artificial selection
Deliberate manipulation by humans as an animal and plant breeding of the genetic composition of a population by allowing only individuals with desirable traits to reproduce
What are the 4 criteria (postulates) of Darwin’s evolutionary process by natural selection?
- Individuals in a population vary in their traits
- Some of these differences are heritable; they are passed onto offspring
- In each generation many more offspring than others
only some survive long enough to reproduce
some will produce more offspring than others - ## Individuals with certain heritable traits Are more likely to survive and reproduce
Adaptation
Heritable trait that increases an individuals fitness in a particular environment relative to individuals lacking that trait the more favored trait will be increased in frequency in pop.
Occur when the allele frequencies in a population change in response to natural selection but they do not occur because organisms want or need them
Polygenetic trait
Any trait that is influenced by more than one gene polygenic traits are usually quantitative traits
Example: beakdepth
Acclimatization
Occurs when an individuals phenotype changes in response to changes in the environment and the individuals genotype remains fixed or the Changes to offspring are not passed down because no alleles have changed
Population thinking
A way of thinking by Darwin the emphasizes the importance of Variation among individuals in a population
Why does natural selection occur?
It occurs by heritable variation that leads to differential reproductive success
Typological thinking
Plato- The thinking that every organism wasa n example of a perfect essence, or type, created by god and that they are unchanging
Aristotle- put the typological thinking In a linear sense based on increased size and complexity
Summarize Plato’s typological thinking
Plato- present species as unchanged types
Summarize Aristotles typological thinking
Present species as an unchanging type, but put in a linear scheme
Summarize Lammarcks theory of evolution
That species are not static but change through time and move up the latter evolution occurs by inheritance of acquired characteristics and spontaneous generation
Summarize Darwin/wallaces theory of evolution
Purposed that evolution occurs by natural selection.
This was the beginning of population thinking
Does not follow linear pattern
Belief is based of variation among individuals in pop.
And that those with certain traits produce more offspring than those without the certain trait
What evidence proves that species change throughtime ? And related by common ancestry?
1) earth’s age
2) exhinchon in fossil record
3> transitional features in the fossil record
4) presence of vestigial traits
57 change in populations that can be observed today
6) geographic proximity of closely related species
7)existence of genetic, duelopmental, and structural homologies
8 formation of new species fun preexisting ones that can be ousted today
Define internal consistency
Date from several independent scorches are mutually reinforcing
Define adaptation
Is a HEREIBLE trait that increases the fitness of an individual in a particular environment relative to individuals lacking the trait
What’s an example of natural selection regarding tuberculosis?
Tuberculosis is an example which cut be observed and measured in populations today, the incidence of drugresistance, herbicide resistance and pesticide resistance are rising
Do individual organisms evolve / adapt or populations as a whole?
Populations as a whole
Is evolution goal directed?
No
Is evolution goal directed?
No
Are all traits adaptable why or why not?
No because
Genetic drift
Change in allele frequency due to chance. Causes allele frequencies to drift up and down randomly overtime, and eventually can lead to the fixation or loss of alleles
Gene flow
Movement of alleles between populations occurs when individuals leave one population, join another and breed
Mutation
Permanent change in the hereditary material of an orgamsm and is the ONLY source of new alleles in populations
Correcting common misconception about natural selection and evolution
1) natural selection does not change individuals
2) natural selection is not “lamarckian” inheritance
3) individuals do not adapt
47 natural selection is not goal directed
5) mutations occur by chance not on purpose
6) evolution is not progressive
7 there is no such thing as a higher or lover organism
87 natural-sellechion does not head to perfection
9)traits are senethallly, environmentally and torlacelly, constrained
10) natural selection is not the only process of evolution
Define biological fitness?
The ability of an individual to produce surviving fertile offspring relative to that ability in other individuals in the population
Can fitness be measured, if so how?
Yes, by comparing the # of surviving offspring each individual produces
Define artificial selection
Deliberate manipulation by humans in animal and plant breeding, by only allowing those with desirable traits to reproduce
Population thinking
Emphasized the importance of variation among indiviahials in a pop.
Darwin claimed that variation among individuals in pop. Was key to understand evolution
Great chain of being
Aristotle’s claim that species were fixed types as Plato had proposed and that some species are higher- in seas of being more complex or “better” than others
Explain lammarck’S theory of evolution
He was the first to purpose a formal theory of evolution
- based on Aristotle’s chain of being simple organisms come from the base of chain by spontaneous generainon
- Organisms evolve by moving up the chain overtime
- lammarckian evolution is progressive
Transitional features
(Basically recent species evolved from traits in more ancient species you’ll see there’s transitional forms overtime that are expected to occur)
What is a example Of transitional features?
The fossil change from the aquatic fin to terrestrial limb
Why was the theory of evolution by natural selection revolutionary
1.it over turned idea that species are unchanging
- Replaced typological thinking with population thinking
- Was scientific
Genetic homology
Is a similarity of DNA nucleotide sequences RNA nucleotide sequences or amino acid sequences
Selection
Differential reproduction as a result of heritable variation
A result of differences in survival, making success, developmental and fertility due to beneficial traits being favored
Fitness trade-offs
Is a compromise between traits interms of how those traits perform in the environment
Every adaptation is a compromise
It is a process in which some living things survive better in the environment and they’re able to reproduce and pass on their genes
Natural selection
