17.2

Explain and give an example of a derived character

Derived character is a feature that involved only within the group under consideration. E.g. Feathers of bird, because the evolved within the bird lineage.

Explain and give an example of a share character.

E.g. Hair mammals Feathers birds

What does embryological mean?

Embryological describes the study of the organism in the early stages of life

Which of the following do cladistic taxonomists not compare when hypothesizing evolutionarily realtionships among organisms

Morphological similarities

What are analogous features. Give examples of analogous features.

These items are the similar due to their function as opposed to similar linneage. E.g. Bats, birds, butterflies

How do scientists use chromosomes to establish relationships one classifying organisms?

They look at gene placement

Systematics

Systematics is the study of biological diversity. Systematics classifies organisms based on natural relationships.

What is an out group?

The out group is the starting point for comparison with other groups being evaluated, during the construction of a cladogram. The out group is purposely distantly related to the other groups.

Describe a clade.

A clade is a group of organisms with the ancestor, plus all of its descendants.

What is a karyotype?

A karyotype is when you take and stain chromosomes in the metaphase during cellular division. The specie's karyotype is then compared with another specie's, and if the banding matches it is likely to have been inherited from a single chromosome in the most recent common ancestor.

What is amnion?

Amnion is the fluid filled sac that in cases an embryo

The molecular-clock model of evolutionary relationships is based on the assumption that changes and macromolecule sequences

Are greater in species with more distant common ancestors

How do scientists use amino acids in the grouping or classifying of organisms?

Biologists count the shared, derived amino acids at each position in a protein and from that they construct a tree that hypothesizes the relationships between various species. This creates a molecular clock which indicates the past evolutionary event.

Include cladistics what term is used for a group of organisms that includes an ancestor and all of its descendants

Clade

Define cladogram.

Cladogram is a phylogenetic diagram created by cladists

The scale is the snakes and the scales of pangolins

Evolved independently in the two groups

What example of a derived character is provided by

Feathers of birds

What type of evidence from the past is used establish relationships among organisms?

Fossils are used as evidence from the past, to establish relationships amongst organisms.

What did the German biologist Willi Henning develop in 1966?Describe what he developed.

He developed cladistics which is a system of phylogenic analysis that uses shared and drivived characteristics as the only criteria for grouping taxa.

What are homologous features? Give examples of homologous features. Recall that HOMO means what.

Homologous are items that are similar and are shared by organisms that have a common ancestry. E.g. Jaws of dogs and pangolins Homo means same.

A clade gram show what type of relationship?

It shows an evolutionary relationship.

What is a phylogenetic diagram? What can a phylogenetic diagram be compared to?

Phylogenetic diagram is what systematists use to express their hypotheses about how closely organisms or taxa are related. It's an indicator of how closely related subset taxa are thought to be. This diagram is comparable to a family tree.

Phylogentics

Phylogenetics is the analysis of evolutionary or ancestral relationships amongst organisms or taxa.

Phylogony

Phylogony is the study of evolutionary history of an organism or taxa

What do systematists use to come up with phylogenetic relationships?

Physical features Embryological development Macromolecules Mitochondrial DNA Ribosomal DNA (proteins)

Need the organisms that are classified as amniotes?

Reptiles birds mammals