The Tree of Life and Phylogeny

Question 1

How has the Tree of Life developed?

Answer 1

Through natural selection and evolution

Question 2

What is natural selection?

Answer 2

process by which individuals that have a certain heritable trait survive to reproduce at a higher rate than individuals without the beneficial trait
stems from environmental pressures
acts on individuals

Question 3

What is evolution?

Answer 3

over many generations, natural selection can cause the accumulation of so many advantageous traits within members of a population that it can become a new species
genetic change over time
acts on populations/species

Question 4

How does genetic variation affect natural selection and evolution?

Answer 4

more allele diversity increases species survival in different environmental conditions

Question 5

How do different selective pressures affect a species?

Answer 5

Over many generations, the environment favors different traits in each population, leading to descendants that diverge genetically and physically, thereby causing evolution two separate species.

Question 6

What is phylogeny?

Answer 6

the evolutionary history of the formation of species, stemming from a common ancestor

Question 7

What are phylogenetic trees?

Answer 7

used understand patterns of evolution

Question 8

What are the two levels of biological diversity?

Answer 8

Intraspecific Variation: different types of alleles among individuals from the same species/population
Interspecific Variation: the variation between millions of different species

Question 9

What is the branch point?

Answer 9

divergence of one group into two separate groups

Question 10

What are talons?

Answer 10

can be the species, genera, family, etc, depending on the reference level you’re observing

Question 11

What is sister taxa?

Answer 11

groups that share a common ancestor

Question 12

What do phylogenetic trees NOT show?

Answer 12

patterns of descent

A taxon did not evolve from a taxon next to it, but rather shared a common ancestor

Question 13

What is cladistics?

Answer 13

the method in systematics that groups organisms by common descent from an ancestor

Question 14

What is a clade?

Answer 14

a group of species that will include an Ancestral Species and all its descendants that share particular traits or characteristics
a lineage grouping that includes an ancestral species and all its descendants

Question 15

What is a monophyletic group?

Answer 15

a clade, groups that share a common ancestor and all its decedents.

Question 16

What is paraphyletic group?

Answer 16

groups that include a common ancestor and some, but not all, decedents.

Question 17

What is a polyphyletic group?

Answer 17

groups that don’t include the common ancestor of its members.

Question 18

What is a shared ancestral character?

Answer 18

trait that originated in an ancestor of the taxon

Question 19

What is a shared derived character?

Answer 19

trait that is an Evolutionary Novelty unique to a particular clade

Question 20

What is a homology?

Answer 20

similarity due to shared ancestry (humans and chimps)

Question 21

What is an analogy?

Answer 21

similarity in morphology occurs in unrelated species due to adaptation to a similar environment (cactus and euphoria)

Question 22

What is synapomorphy?

Answer 22

a characteristic present in an ancestral species and shared exclusively by its evolutionary descendant

Question 23

What is an outgrip?

Answer 23

a living species or group that is most closely related to the in-group (clade) being studied
usually represents a species that most closely resembles a common ancestor before branch divergence

Question 24

What is taxonomy?

Answer 24

naming through a two part species name or hierarchical classification