Unit 1 terms Flashcards
natural selection
a mechanism of evolution that favors heritable traits that increase an organism’s chance of survival and reproduction
fitness
the ability of an individual to successfully reproduce
evolution
change in the genetic composition of a population over time
adaptation
an increase in fitness due to evolution
genotypes
the specific genes of a trait
phenotypes
how the trait is actually presented
Natural Theology
Earth is young; everything is according to the Scala Naturae; species don’t change
catastrophism
change occurs randomly
* fossil records
uniformitarianism
change is uniform
Lamarck
spontaneous generation produces species that evolve over time due to 1. drive towards complexity 2. adaptive force (giraffe neck example)
Malthus
populations increase over time; food production can’t keep up; not everyone can survive
On the origin of species
famous publication by Darwin in 1859
hypothesis
testable prediction
theory
strongly supported explanation, often deemed fact
law
specific prediction derived from a broader theory
evolution occurs on a level of ___
population
3 conditions for evolution by natural selection
- variability among species
- traits are heritable
- difference in survivability
comparative study
compare populations from naturally-differing environments
experimental study
actively manipulate the population or environment to create differences
common-garden experiment
bring samples of populations into the same lab to grow under the same conditions
know the bacterial resistance example
some bacteria had a mutation that made them resistant to an antibiotic – these bacteria could survive and reproduce more
transitional species
transitional forms of species will be found in past or current populations (ex. whales)
biogeography
species in closer geographic proximity should be more closely related when species cannot easily disperse
taxonomic relationships
species that diverged more recently share more features than those that diverged longer ago
homologous and vestigial traits
complex structures and functions cannot appear from nothing, but must evolve from existing structures (ex. limb bones in terrestrial vertebrates)
adaptation vs. acclimation
adaptation: long-term evolutionary change in response to a changed environment
acclimation: short-term adjustment to a changed environment
evolution is not ________
PROGRESSIVE; species may become more/less complex or gain/lose traits (use derived)
ex. flightless birds from flighted birds
what is wrong with acting “for the good of the species”
there is no objective “good” for a species; there is no target for how evolved a species needs to be
vestigial traits
traits that have lost their function in a particular species
Hardy-Weinberg principle
allele and genotype frequencies will remain constant from one generation to the next without evolutionary conditions (use allele frequencies to predict genotype frequencies)
Hardy-Weinberg conditions
- no natural selection
- no genetic drift
- no gene flow
- no new mutations
- random mating
assortative mating
mates are chosen for their similarity (+) or dissimilarity (-) to self
positive assortative mating ex.
mating for height (two tall people mate)