Evolution Flashcards
Stromatolites
Fossilized Cyanobacteria
Coelacanth
A fish group ancestral to amphibians
Evolution
The gradual change or development of something
Biological evolution
The change in the gene pool of a population during the course of time by such processors as mutation, natural selection and genetic drift
Micro evolution
Evolution within a species
Macro evolution
The descent of different species from a common ancestor over many generations
Lamarckism
‘Soft’ inheritance
Inheritance of acquired characteristics
Evolutionary change
Species had modified gradually from ancient ancestors unlike themselves
Natural selection
Individuals best adapted to the environment will leave the most offspring
Paleontology
Study of prehistoric life
Cambrian explosion
(Began 545 million)
Rapid diversification over a relatively short period of 5 million to 10 million years led to the appearance of a huge diversity of complex, multi-celled organisms
Cladogenesis
Branching- shows modified descendants
Cladogram
An family tree that shows evolutionary relationships
Biogeography
The study of where species (both present day and extinct) occur and why
Oceanic islands
Usually formed as the result of volcanic action and are often geographically ‘young’
Comparative anatomy
Comparing external and internal structures to find out how related two structures are
Homologies
Similar structures or characteristics that organisms have acquired from a common ancestor, showing that they are on the same evolutionary lineage
Homologous structures
Same structure; different function
Structures derived from a common ancestor but evolved in different environments
Analogous structures
Same function; different structures
Similar structures in different organisms because they evolved in similar environments
Vestigial organs
Structures or organs that seem stunted and have no function
Peer review researchers
Experts in the same field who look for weaknesses and errors, and make an unbiased evaluation of the piece of research
Phylogeny
The scientific study of evolutionary relationships among species
Phylogenetics
The study of the evolutionary relationships among groups of organisms which have been discovered through extensive evidence
Clade
A life-form group consisting of a common ancestor and all its descendants- representing a single ‘branch’ on the tee of life
Anagenesis
He gradual accumulation of changes to an ancestral species which leads to the species being sufficiently distinct from its original starting form, so that it can be labeled as a new species
Adaptive radiation
The burst of divergence from a single lineage to give rise to many new species from a single ancestor
Gradualism
Hypothesis which put forward that species evolve gradually by small changes over long periods of time
Punctuated equilibrium
Refers to the speed at which evolution takes place
Germ-line
In the eggs or sperm
Gene flow
The movement of genes between populations
Genetic drift
A process that produces random changes in the frequency of characteristics in a population.
Artificial selection
The process of selecting and breeding organisms with desirable characteristics
Inbreeding
The mating of closely related individuals
Outbreeding
The mating of individuals not closely related
Neoteny
Retention of immature characteristics in adults
Classical plant breeding
Uses deliberate interbreeding of closely or distantly related individuals of a species to produce new crop variations with desirable traits
Embryo rescue
The rescue of embryos and seeds of valuable plants
Natural selection
Process by which nature (the environment selects for survival those individuals that are best adapted to environmental conditions, and as a result, will produce the most offspring
Differential reproduction
Better adapted individuals would survive to reproduce
Survival of the fittest
HYV’s
(High-yielding varieties)
Hybrid crops with increased growth rates and yields
Cultigens
Domesticated plants dependent on humans for cultivation
Mutagenesis
Production, by chemicals or radiation, of mutants that may have desirable characteristics
Random mating
Every female gamete, with her particular genotype, has an equal chance to be fertilized by every male gamete, with his particular genotype in the population
The founder effect
Loss of genetic variation when a very small number of individuals from a larger population establish a new colony
Fecundity
The ability to produce abundant healthy offspring
Convergent evolution
Process during which species that are not closely related to each other independently evolve similar kinds of traits to adapt to similar environments or ecological niches
Speciation
The divergence of one species into two or more descendent species.
Evolutionary formation of new species that are genetically distinct from the older, parental species
Extinction
Permanent loss of all meme era of a species
Geographical speciation
New species is formed as a result of whole/ part population = geographically isolated from ancestral species
Sympatric speciation
A new species arises in the same area as ancestral species without any geographical isolation
Polyandrous
Having multiple male partners
Reproductive isolation
Mechanism that prevents two or more species from interbreeding and producing viable, fertile hybrids even though they are not geographically separated
Allopathic
Geographical isolation
Stridulating
To make a chirping/ grating sound by sound by rubbing certain parts of the body together
Biological species
A group of organisms of common ancestry that closely resemble each other and can inbreed to produce viable offspring
