L2: Anatomy & Evolution Flashcards
Learning Objectives: 1. Recognise phylogenies and understand where we sit in the phylogenetic tree 2. Understand how phylogenies are arrived at 3. Understand the we are chordates and the features that define this phylum 4. Know the major groups of vertebrates 5. Understand the differences between the vertebrates and other chordates 6. Understand the differences between jawless and jawed vertebrates 7. Understand the features that define us as tetrapods, amniotes and mammals
What is phylogenies?
Trace patterns of shared ancestry between lineages
What is a phylogenetic tree?
Graphical representation of evolutionary history
What is ontogeny?
The origination & development of an organism, usually from the time of fertilisation of the egg to adult
What is phylogeny?
Evolutionary history & relationships among a group of organisms
What kind of organisms will share more closely related genes?
Related organisms
What can be constructed using comparisons between gene sequences from different organisms?
Phylogenies
What was previously used to construct phylogenies?
Ribosomal RNA genes
What are chordates?
Animals with a flexible rod supporting their back
What were the new adaptations for vertebrates?
Complex CNS, paired sense organs
What was the evolution of vertebrates regarding jaws?
Went from jawless to jawed vertebrates
What were vertebrates able to do after the evolution of jaws?
Explore new ecological niches
How many nostrils in cyclostomes?
1
How many nostrils in gnathostomes?
2
Anatomical changes of tetrapods?
Fins to limbs
Loss of gills
Developed a mobile necj
What is locomotion?
Ability to move
What are tetrapods?
Vertebrates that live on land, characterised by 4 limbs