Biology of Animals

Science

is the knowledge or a system of knowledge covering general truths, or the operation of general laws especially as obtained and tested through scientific method/process

Basic science

seeks to understand fundamental principles and natural phenomena

Applied science

solves specific problems and create tangible solutions

scientific process

is an iterative and nuanced dynamic process to describe observable patterns and their processes in the physical world

Theory

outlines well-supported explanations about the natural world; can include laws, hypotheses, and observations

Hypothesis

is a statement about the natural world that can be tested; a falsifiable and general explanation regarding a natural phenomenon

Predictions

are statements about what is expected to be observed in a particular system under specific conditions

Proximate

immediate, internal factors that cause a trait to occur (how)

Ultimate

evolutionary history and adaptive significance of a trait (why)

Genes

contain coded information passed from parents to offspring, which – in addition to environmental factors – guide development of an organism

Animal cell

the nucleus contains genetic material

Genotype

organism’s genetic information (DNA)

Phenotype

expression of organism’s genetic information (amino acid)

Recombination

exchange of genetic material between different organisms which leads to production of offspring with unique combos of traits from parents

Meiosis

cell replication

Crossing over (prophase)

exchange of genes between homologous chromosomes

Mutation

a permanent change in the DNA structure of a gene that results in variant form

Substitution

one nucleotide is swapped for another

Deletions

removal of a nucleotide

Insertion

addition of a nucleotide

Inversions

a segment of a chromosome flips 180 degrees

Alleles

a variant of the same gene

Homozygous dominant (AA)

dominant trait shown

Heterozygous (Aa)

dominant trait shown

Homozygous recessive (aa)

recessive trait shown

Species

classification of living organisms that can interbreed and produce fertile offspring

Evolution

change in allele frequency in a population across generations

Microevolution

small-scale changes within a population (modification)

Macroevolution

large-scale changes at species level and above

Hardy Weinberg Equilibrium

indicates the absence of evolution. Allele and genotype frequences will maintain constant proportion from generation to generation. Change over 5%  evolution.

p

frequency of homozygous dominant genotype

2pq

frequency of heterozygous genotype

q

frequency of homozygous recessive genotype

Genetic drift

the proportion of individuals in a population reproducing will likely not represent the population

Gene flow

between a population, alleles will move

Natural selection

organisms with heritable traits better suited for their environment are more likely to survive and reproduce

Trait variability

variation within a population

Trait hereditability

genetic basis to variation

Population growth

must be producing more offspring than environment can handle thus facilitating competition

Fitness and trait correlated

favorable variants have highest success

Adaptation

when a derived trait evolved in response to a specific selective agent increases the fitness of an organism compared to those without the trait

Adaptive traits

increase the relative fitness of an individual with respect to others in the same environment

Relative fitness

an individual’s total number of offspring standardized by the max number of offspring produces by individuals in a species’ population

Plasticity

occurs when one genotype can generate different phenotypes in response to the environment

Tradeoffs

enhance one aspect of fitness while simultaneously decreasing other aspects of fitness

Evolutionary constraints

limitations to adaptive evolution

Heritability

how much variation of a trait is present within a population due to genetic differences

Taxonomy

systematic ordering and naming of organisms

Systematics

the science of taxonomy and reconstruction of phylogeny

Phylogenetics

the study of evolutionary relationships

Phylogeny

a visualization of hypothesized evolutionary relationships among taxa organized in a nested hierarchy

Cladogenesis

splitting of a parent lineage into descendent lineages, clades

Most recent common ancestor (MRCA)

the inferred, shared ancestor between two clades

Root

the base of the tree showing the most ancient ancestor

Tips

taxonomic groups shown as the most recent part of the tree

Nodes

divergent points where phylogeny splits the ancestor to two lineages

Branches/lineages

the line connecting ancestors to descendants

Characters/transitions

traits that indicate changes in a lineage (phenotypic or genetic)

Sister groups

taxa that share MRCA with each other

Autapomorphy

unique, derived character

Synapomorphy

shared, derived character

Plesiomorphy

shared, ancestral character

Monophyletic group

include a common ancestor and ALL descendent lineages

Paraphyletic group

include a common ancestor and SOME descendent lineages

Polyphyletic group

include some ancestors and some descendent lineages