bio 2 exam 1 cozza fiu

speciation

branch point

multiple speciation events leads to

more branches

most of the tree

will never be known

parsimony

fewest changes

maximum likelihood

given certain rules about how DNA changes over time, a tree can be found that reflects the most likely sequence of evolutionary events

homology

shared character from a common ancestor

informative homology types

morphology, develeopment, behavior, cell structures, molecular(chromosomes, dna sequences, proteins)

rare genomic changes

give more traits and are v informative

wedge shape

branching diversity within a clade

mrca

most recent common ancestor

ancestral character

Evolved in a common ancestor of both groups

ancestral branch

evolved right off the mrca

derived character

trait that appears in recent parts of a lineage, but not in its older members

derived clade

the group with the derived character

Synapomorphy

shared derived character

Homoplasy

The separate evolutionary development of similar characteristics in different groups of organisms.

outgroup

closely related taxon with ancestral traits, may not be shown

clade

A group of species that includes an ancestral species and all its descendants.

ingroup

not the outgroup

sister taxa

Groups of organisms that share an immediate common ancestor and hence are each other's closest relatives.

monophyletic

ALL descendants came from one common ancestor

paraphyletic

Pertaining to a group of taxa that consists of a common ancestor and some, but not all, of its descendants.

polyphyletic

pertaining to a group of taxa derived from two or more different ancestors

polytomy

a branch point from which more than two descendant groups emerge

Phylogram

Branch length is proportional to the amount of evolutionary change

Virus-first hypothesis

Viruses existed before cells

Progressive hypothesis

Existing genetic elements gradually gained the ability to move from cell to cell

regressive hypothesis

Viruses are cells that lost some of the replicative and metabolic traits over time

bacteria cell wall

peptidoglycan, mesh

gram positive

1 membrane, thick wall

gram negative

Thin walls, outer and inner membrane

genetic recombination by lateral gene transfer

Involves plasmid

shapes of bacteria

round, rod, and spiral

Multicellularity

Single species, division of labor, some cells give up reproduction

Biofilms

Wildly concerning

Great Oxidation Event

Thanks to bacteria

Stromatolites

Producing the earths atmospheric oxygen

How many organisms in the bosy

100+ trillion

Flagella owners

Archaea and bacteria

Archaea are everywhere

Open ocean, soil, lake water, animal guts, skin