topic 6 - co-evolution conflict

Molecular clock

Character change in molecular phylogeny can occur in a clock like fashion that enables us to put time stamps on evolutionary events

Cladogram

Phylogeny

Parsimony

Requiring the fewest assumptions or evolutionary changes - is mot likely to be correct

Used in phylogenetic to infer evolutionary relationships

Favours the tree that explains the data with the least number of evolutionary steps (like mutations or trait changes)

List three factors we need to know to construct a parsimony

Character data: these are the traits or features you’re comparing across species; can be morphological (eg number of limbs, presence of feathers), molecular (eg DNA or protein sequences)

Character states: describe the form or version of each trait in each species (eg presence of a backbone)

Adaptive phenotype

Set of observable traits (morphological, physiological, behavioural) that increases an organism’s fitness - meaning it improves the individual’s ability to survive and reproduce in its specific environment

Phenotype

Any observable characteristic, such as body size, colouration, metabolism or behaviour that results from the interaction of genes and enviornment

Adaptive

The trait provides a selective advantage in the current environment (eg camouflage reduces predation, thicker fur in cold climates, antibiotic resistance in bacteria)

Natural selection

Favours adaptive phenotypes because individuals with these traits tend to leave more offspring, spreading the advantageous genes through the population.

Reproductively isolated

Population structure

Arises when the demographic processes produce systematic differences in allele frequencies between subsets of a larger population

Isolation or some other factor that causes non-random mating

Eg. Western and Eastern deer separated by mountain range. No gene flow can happen. Relatively recent opening of the pass allows gene flow