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43 Cards in this Set

  • Front
  • Back
homologous structures
common structures all members of one species share
transitional fossil
linked to other fossils by a common ancestor...fills in gaps and shows transitions
relative dating
assumption that older things will be in deeper layers and more recent in higher layers
radiometric dating
using half-lives of radioactive isotopes to calculate how much time has passed since the isotope was in its original form
vestigial structures
structures w/ no function, although they may be or have been in the past useful to other members of the species
comparitive embryology
study of developing organisms
what 2 things can scientists use to compare and determine weather 2 organisms are closely related, solely based on the similarity?
DNA and amino acid sequences
where fossils are found (scientists rely on this evidence)
what causes genetic variety in a population?
recombination (during sexual reproduction) and mutations
what is natural selection?
the process by which those who are best suited to their poulation survive and reproduct, whiel those who aren't suited die off
what is the founder effect
when a small poulation w/ limited diversity founds a new population in a new location, in breeding occurs and there is limited genetic variety (ex: amish six fingered hand)
ability to walk on 2 feet and the big toe is aligned w/ the 4 others (distinuishing characteristic between humans and other primates)
genetic drift
rapid change in #'s and kinds of genes in a small isolated population that may lead to the evolution of a new species (ex: bioengineered foods in the environment by wind)
drug resistent pathogens
created by the overuse of antibiotics, over perscription, antibacterial products, etc, these are organisms that cause illness but are resistent to treatment
darwins theory of evolution
1) overeproduction occurs in the environment
2) organisms die (limited resources)
3) variations through recombination and mutations occur
4) offsring continue to inherit variation
5) variations that are suited to the environment carry on, those variation that aren't die out
6) population changes as a response to the environment
products of evolution by nat. selection
raw materials upon which nat. selection acts
structural adaptations
those involving structure or anatomy
physiological adaptations
adaptations with a chemical basis
behavioral adaptations
adapting in their responses to the environment...ex: hunting for prey, growing toward light, etc.
gorup of organisms that can interbreed and produc ferile offspring
geographic isolation
river, canyon, mountain forms and populations are split apart. diff environments=diff variations, therefore diff speceis
convergent evolution
species not closely related evolving similar traits b.c they live in the same or similar environments
punctuated equilibrium
hypothesis that asserts that the normally slow and gradual process of evolution is broken by short periods of rapid chage
evolution of a new species
divergent evolution
one species evolves into 2 or more species
adaptive radiation
ancestral form meets new environment, has basic adaptations suited to environment, and is free from competition. usually a species gets to a new environment, splits up and each takes on diff. roles.
ancestral web for humans
african apes anthropoids
Austrilipithecus afarensis
3.5 million years old...Lucy gave evidence that upright walking evolved before large brain (she had a small brain, 3 ft tall, and was bipedal)
Homo Habilis
"handy man" first to USE tools, largest brain capaciy so far. good learning capabilities, hunted.
homo erectus
1 million years ago, first to Make tools, larger brain capacity, flat face, learned to make and use FIRE, lived in groups
homo sapiens
appeared 100,000 years ago, developed burials for the dead, language, etc.
modern system of classification created by
branch of biology that classifies organisms based on characteristics
binomial nomenclature
2 name naming system- Genus, species.
taxon (groupings)
Kingdom, phylum, Class, Order, Family, Genus, Species
animal, chordate, mammal, primate, hominid, homo, sapien
name all kingdoms and approximate #
animals > 1 million, plants > 500,000, fungi > 100,000, protists >100,000, (monera---> eubacteria >10,000; archaebacteria "ancient" 3.8 billion years old)
evolutionary history of a species
classification system based on phylogeny
evolutionary tree
Dichotomous key
step by step way to identify organisms using paired questions
first classification system---> water, land, air animals