Chapter 5 Adaptations Flashcards
Ecology
study of the interactions of organisms and their environment
Ecosystem ecology
interactions with physical environment that involve feedback mechanisms
Population ecology
mechanisms relating to competition within a population
Community ecology
Community - mechanisms relation to the interaction between species
Adaptation
characteristics that enable an organism to thrive in a given environment (these characteristics are heritable)
Environmental Tolerances
environmental conditions beyond which an organism can no longer maintain a positive response (many different rages from survival, growth, reproduction, and optimal)
Gene
stretch of DNA coding (eye color)
Allele
forms of a gene (brown eyes allele or green eyes allele)
Locus
position occupied by a gene on the chromosome is called this
Gene expression
process of creating proteins from the genetic code in DNA
Genotype -
genetic makeup of an organism (combined genetic material)
Phenotype –
the expressed traits of an organism (physical expression of genotype)
Two models of gene expression
complete dominance and incomplete dominance
Complete dominance
one allele is completely dominant
Incomplete dominance
heterozygous individuals are intermediate where each allele has a proportional effect on the phenotype
Homo/heter zygous
dependent on alleles at this locus. If the alleles are same vs different at the locus
Norm of reaction –
set of phenotypes expressed by a genotype in different environments…
Phenotypic Plasticity -
ability of a genotype to express different phenotypical characteristics under different environmental conditions
Acclimation –
reversible phenotypical changes in an organism in response to changing environmental conditions
Developmental plasticity –
differences in phenotypical traits for a given genotype under different environmental conditions that OCCUR DURING GROWTH AND DEVELOPMENT THAT ARE IRREVERSIBLE!
Natural Selection –
differential success of individuals within the population resulting from their interaction with their environment
Conditions for Natural Selection:
- variation among individuals in relation to some heritable characteristic 2. that variation among individual results in differences in their survival and reproduction
Fitness –
measured by the proportionate contribution an organism makes to future generations… number of offspring produced that contribute to future generations
Three forms of selection
stabilizing, directional, disruptive
Stabilizing selection –
selection (directional, stabilizing, and disruptive)
Stabilizing – the mean phenotype in a population exhibits the highest relative fitness, and this form of selection looks to decrease all non-conformers/outliers
Directional selection–
distribution of phenotypes is shifted to an extreme… birds with only super huge beaks compared to the population survive for some reason
Disruptive selection
relative fitness is greatest for the extreme vales of phenotype… ends up with a bimodal distribution (cannot be a middle dude… only an outlier dude)
Gene pool
sum of genetic information(alleles) across all individuals in the population is referred to as this
Ways that genetic variation in gene pool can be quantified:
Allele frequency – proportion out of all the alleles present at the local in the population
Genotype frequency – proportion out of all the genotypes present at the local in the population
Two levels that genetic variation can occur:
within subpopulations and among subpopulations!
Genetic differentiation
genetic variation that occurs among subpopulations of the same species… looking at genetic variation between different subpopulations
Cline
measurable gradual change over a geographic region in the average of some phenotypic characteristic
Ecotype
a population adapted to its unique environmental conditions (marked discontinuities among local populations (there are two ecotypes of mice one for fields and one for beaches remember!!)
Ecotype vs Cline
cline more describes the change in a specie’s phenotypical characteristics, whereas ecotype describes the population adjusted to its environment
Reciprocal transplant and common garden experiments
comparing the shape of “naturally occurring populations” of a plant TO the shape of a plant in a “common garden”.
if the plant has the same shape as before then this implies genetic differentiation
if the plant starts to look different then this implies phenotypical plasticity
Adaptive radiation
the evolutionary diversification of a species or single ancestral lineage into various forms that are each specialized to a specific environment/resource
Codominance
when both alleles are expressed when usually there is no one dominant allele
evolution
changes in properties of populations of organisms over the course of generations
Target of selection
phenotypic trait that select acts directly upon (beak sizes leading to natural selection makes beak sizes the target of selection)
Selective agent
environmental cause of fitness differences among organisms (in the birds example, the change in available food resources would be the selective agent)
Genetic drift
the random chance of how only some genes are passed along to future generations
Hardy-Weinberg Principle
no evolutionary change occurs through the process of sexual reproduction alone! Must accompany with natural selection or some sort of selective mating form!
Qualitative vs Quantitative Traits
Qualitative- discrete categories (red or blue)
Quantitative - continuous distribution (height or weight)… most things are quantitative
What does the idea that “beetles become darker in development which helps them absorb more warmth when adults to accommodate for coldness”
Developmental plasticity that aids in the survival of the organism!
Only process that leads to adaption
Natural selection
Mutations
Heritable changes in a gene or chromosome… whether or not there mutations are beneficial depends on the environment!
Migration vs gene flow
Migration- movement of individuals between local populations
Gene flow- movement of genes between populations
You can have migration without gene flow if it doesn’t reproduce!
Other than natural selection, what are some ways that genetic variation can be altered in populations?
Mutations and genetic drift
Merging of ecotypes is called
Zone of hybridization
Geography/boundaries influence ecotypes a lot! (t/f)
True!
Read page 84/85!!
Yes read those!
You have pics!
