Exam 1 - Week 4/5 Chapter 8 & 4 Flashcards
Essence of natural selection
more offspring produced in a pop than can survive
Variation in characteristics occurs in the population
Variation in biological fitness occurs in the population
individuals in the population compete for resources
influence which individuals with a given genetic phenotype will best survive and compete, and thus will leave the most offspring in the next generation
prevailing environmental conditions
why are the gophers of white sands national monument not white when gophers elsewhere match moist soil coloration
trade off - dark pigmentation is more resistant to wear and tear.
sesamoid bone
a bone embedded within a tendon
pandas - acts like a 6th finger to help hold onto bamboo
moles - makes hand paddle like so its easier to dig
what is the BEST measure of fitness
the number of copies of your genes left in future generations; extremely hard to measure
convergent evolution
the independent origin of similar traits in separate evolutionary lineages
ex. wings (seen in birds, bats, beetles - but they are all in different lineages)
a visual representation of the evolutionary history of populations, genes, or species
phylogeny
analogous structures
structures that are similar because they have converged on a shared form. they are not derived from a common ancestor
character state similarity not due to shared descent (produced by convergent evolution or evolutionary reversal)
homoplasy
monophyletic groups
groups of organisms that form a clade
an organism and all of its descendants
clade
a shared derived character; this is a character that evolved in an immediate common ancestor
synapomorphy
convergent evolution
(a cause of homoplasy) independent evolution of similar trait
evolutionary reversals
(a cause of homoplasy) reversion back to an ancestral character state
a criterion for selecting amoung alternative patters or explanations based on minimizing the total amount of change or complexity
parsimony
