Evolution Unit Flashcards
What’s Darwin’s theory?
• species can evolve over TIME
• and that all species share a common ancestor
what is RADIOMETRIC DATING used for?
• to determine the AGE of the EARTH
what is FITNESS in evolution?
• the lifetime reproductive SUCCESS for an individual
what are VESTICAL STRUCTURES?
• structures that previously had a function, but don’t anymore.
• such as the wisdom tooth
what is NATURAL SELECTION?
• organisms that are more ADAPTED to an environment than others, are likely to SURVIVE & REPRODUCE
EMBRYOLOGY & DEVELOPMENT
• in early stages , many embryos are SIMILAR, but these similar traits disappear over time .
• like birds, fish, mammals have gill slits
what is the theory of PUNCTUATED EQUILIBRIA?
• species evolve really FAST (like a burst??), not gradually
what is LAMARK’s take on evolution?
• if organisms change to adapt to a new environment, they will evolve in their lifetime & pass the new trait to their offspring
what are FOSSIL RECORDS?
• fossils that help trace ancestors to animal that are alive now
what is DNA COMPARISON?
• the more SIMILAR the dna pattern, the more CLOSELY RELATED
• giant panda / bears
what is SPECIES DISTRIBUTION?
• long distanced species in similar environments evolve differently
what are the 5 LINES OF EVIDENCE for evolution?
- comparative anatomy
- embryology & development
- fossil records
- DNA comparison
- species distribution
what are 5 FACTORS that cause EVOLUTIONARY CHANGE?
- genetic drift
- mutations
- gene flow
- natural selection
- sexual selection
what’s CATASTROPHISM
• a theory that said that natural disasters killed off old species
DARWIN’S JOURNEY
• sailed for 5 years to research rocks, plants, minerals, organisms
• galipago islands
• struggled in his research with heredity
what are MUTATIONS?
• they occur in DNA
• more genetic variation = more chance of selective advantage
• harmful mutations are less likely to be passed down
what is GENE FLOW?
• the net movement of ALLELES From one population to another as a result of migration
what is GENETIC DRIFT?
• change in the genetic makeup resulting from chance
EX: gene C is 2% of the population
1000 people = 20
100 people = 2
what is EVOLUTION?
a process in which significant changes occur in a species
what are HOMOLOGOUS STRUCTURES in comparative anatomy?
similar in origin but different in function
• dolphin flipper / human hand
• divergent evolution
what are AMALAGOUS STRUCTURES in comparative anatomy?
similar in function but different in origin
• butterflies’ / birds’ wings
• covergent evolution
what is SEXUAL SELECTION?
the preference of a certain trait in an individual of the opposite sex
• bright colours in male birds
