Major Transitions In Evolution Flashcards Preview

Evolution > Major Transitions In Evolution > Flashcards

Flashcards in Major Transitions In Evolution Deck (6)
Loading flashcards...
1
Q

What are the eight transitions?

A

Replicating molecules-> molecules in compartments

Independent replicators -> chromosomes

RNA as gene and enzyme -> DNA and protein (code)

Prokaryotes -> eukaryotes

Asexual clones -> sexual reproduction

Protists -> multicellularity

Solitary -> colonies

Primitive societies -> human societies with language

2
Q

Why are they major? (6)

A
  1. Focuses on major changes in how info passed between generations
  2. Not major phenotype transitions
  3. Had to be selected for
  4. Increase fitness
  5. Differences we see now, may not be first reason that they were favoured
  6. Ancestral version hypothesised bs ancestral version still extant.
3
Q

Replicating molecules to molecules in compartments

A

Origin of cells

4
Q

Independent replicators to chromosomes

A

Genes

Collection of multiple genes:

  • slower to replicate (bad)
  • chromosomes selected for (good)
  • info is more robust as linked genes have synchronised replication (good)

Prokaryotes are circular and eukaryotes are linear

Caenorhabditis elegans (worm) 
-were complex like this worm
5
Q

RNA as gene and enzyme to dna and protein

A

Transition from enzymatic replicator
-bad as need to make translocation system

System needs to have single origin

Amino acid have more chemical functions than nucleotides so they’re food cofactors (essential to enzymes).

6
Q

Prokaryotes to eukaryotes

A

Eukaryotes:
Cytoskeleton maintains shape
Internal membranes
Linear chromosomes in nucleus

Prokaryotes:
Ridged cell walls
No internal membranes
Single circular chromosome