Honors HSBio 12 - Natural Selection and Evidence of Evolution

evolution

change over time

artificial selection

selective breeding of plants and animals to get desirable traits

natural selection

process by which traits that help organisms survive are "picked" by nature.

homologous structures

structures on different organisms that have similar internal bone structures but different external forms. (Ex: human arm and cat leg)

vestigial structures

structure that has lost much of its original fuction (ex. appendix)

analogous structure

structures on different organisms that have different bone structure but provide the same or similar function. (Ex: dolphin fin and shark fin)

diversity

a variety of traits or genes among a population or between populations

cladogram

a diagram that shows shared characteristics among species

fitness

how well an organism can survive and reproduce in its environment

sexual selection

selection of mates based on heritable traits

adaptations

characteristic an organism is born with that increases an organism's abiltiy to survive and reproduce

species

group of organisms that can reproduce fertile offspring

embryo

early stage in development of humans and other animals or plants soon after fertilization between egg and sperm

logistic growth

a pattern of growth that starts off exponential but then slows as the population reaches its carrying capacity in the environment...making a "S" shape graph

exponential growth

a pattern of growth where the population grows at a constant rate that does not stop...making a "J" shaped graph

carrying capacity

largest number of individuals of a species that can be supported in a environment

common ancestor

an extinct ancestor organism that is shared by two or more species