Chapter !7 - Genomes of Eukaryotes Code : KSI0016
<Index of Chapter 7>
The origin and evolution of eukaryotes
-In order to reconstruct evolutionary history from genomes, we must analyse genomes from species, the ancestors of which first arose in the distant past. What do they share with their close relatives, that might offer genomic characterization of a group of species. What are the defining genomic features of vertebrates ? What do ancient species share with their precessors and successors? What innovations did they achieve? Which of those were dead ends and which did other species descended from them adopt and develop?
Evolution and phylogenetic relationships in eukaryotes
-The yeast genome
-The evolution of plants
> Plants share some functions with animals. At the genomic and proteomic level, are they achieved in similar ways?
> Some functions are unique to plants. At the genomic and proteomic level, where did they come from? Were they invented, adapted, or borrowed?
-The genome of the sea squirt
> Vertebrates arose within the chordate phylum, branching off from other lines that led to seq squirts and lancelets. The sea squirt represents one of the most primitive of our chordate relatives. Its genome provides insight into chordate and vertebrate origins.
-The genome of the pufferfish
> The pufferfish is a vertebrate. At least 3- quarters of its genes have human homologues. By comparision of its genome with humans, it's possible to reconstruct the ancestral vertebrate karyotype.
-The chicken genome
>milk proteins such as casein
> enamel proteins, associated with loss of teeth in the itd lineage subsequent to Archaeoptertyx a primititive bird that did have teeth.
-The platypus genome
-The dog genome
> Dogs and humans have lived and cared for each other for over 10000 years. Dogs are work, sport, and companion animals.
The dog is an outgroup of other mammals for which complete genome sequences have been determined.
Dogs are an ideal species in which to study domestication .
Dogs share many human genetic disease.
Because many drugs are tested in dogs, understanding of their molecular biology is useful.
Dogs show a vast morphological variation, notably in size.
Palaeosequencing - ancient DNA
-Recovery of DNA from ancient samples
DNA from extinct birds
-The moas of New Zealand
- The dodo and the solitaire
High-throughput sequencing of mammoth DNA
-The mammoth nuclear genome
-The phylogeny of elephants
Returning to the question of what defines species boundaries, it is clear that this distinction was drawn at least rimarily on the basis of similarity of DNA sequence. What about the classical biological definition of whether the species hybridize in nature.
