Evidence For Evolution 5 Types
Embryology
Homologous Structures
Genetics
Radioactive Data
Fossils
Common Ancestor
ancestral organism shared by 2 or more descendant lineages (AKA an ancestor 2+ organisms have in common)
Embryology (supports Evidence for Evolution)
Study of embryos (unborn developing offspring)
Embryos of different animals look similar
suggests all animals are related and come from a a common ancestor
Homologous Structures (supports Evidence for Evolution)
The (similar) body parts of different organisms - suggests common ancestor
Difference shows that organisms evolved to adapt to different environments
Genetics (supports Evidence for Evolution)
All living things have dna
Closely related species have similar dna
Suggests all living things evolved from common ancestor
Humans and fruit flies have similar dna sequences - diffferent looking things can be closely related
radioactive data (supports Evidence for Evolution)
Shows age of rocks
Rocks contain fossils - know age
Fossils show life has existed for millions of years
Gives lots of time for evolution to happen
fossil (supports Evidence for Evolution)
Remains of once living organisms
Old vs recent fossils look different
Older fossils from different time periods gradually look more like recent fossils
Proves organisms haven’t remained the same on earth - they’ve become more complex
5 steps of natural selection
Variation
Competition
Survival
Reproduction
Overtime Population Evolves
Variation (step of natural selection)
Individuals of the same species have different versions of the same trait
VERIETY of a trait=biodiversity
ex; hair
Competition (step of natural selection)
Organisms produce more offspring than can survive
Therefore it causes those individuals to compete for LIMITED RESOURCES
Survival (step of natural selection)
Individual with FAVORABLE VERSION OF THE TRAIT is better adapted to their environment; they OUT-COMPETE others and survive
Reproduction (step of natural selection)
Individuals more likely to SURVIVE are more likely to pass favorable trait to offspring
Individual with unfavorable trait is more likely to die without reproducing and PASSING ON ITS GENES
Overtime Population Evolves (step of natural selection)
Over many generations population EVOLVES to include more individuals with favorable trait and less with unfavorable trait aka FREQUENCY
Species
a group of living organisms that can interbreed and produce fertile offspring, meaning their young can also reproduce
Biodiversity
All the different kinds of life you’ll find in one area (animals, plants, microorganisms aka bacteria)
Speciation (step of speciation) and definition
Formation of a new species from an already existing species.
2 populations can no longer produce fertile offspring, therefore they are two separate species
Reproductive isolation (step for speciation)
When two groups of the same species can no longer interbreed
Four steps of speciation
Geographic separation
Reproductive isolation
Genetic divergence
Speciation!
Geographic separation (step for speciation)
Two populations of the same species become isolated from each other
Genetic divergence (step for speciation)
They are adapting to new environmen; the two populations will independently change over time to adapt to their environment via naturally selection
Natural selection
Process by which organisms within a species that are better adapted to their environment survive and reproduce more successfully. (With reproduction they pass genes made of dna for beneficial apaptations to their offspring)
What is trait frequency?
How often a specific version of a trait appears in a popultion
How to calculate trait frequency
individuals with specific trait / # individuals in population • 100%
Three things natural selection is based on
Heritable traits; traits are genetiaclly based characteristics passed on in form of genes
Variety; there’s variety within a heritable trait of species
Limited resources and comp; species produce more offspring that can survive, creating infraspecific competition
