phylogenetics
Tags
bio/eco
cegep/3
Word count
175 words
Reading time
2 minutes
Study of the evolutionary history of life
[!abstract] phylogenetic tree
Tree representing the evolutionary history of taxaAka.phylogeny
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Hypothesis
The phylogenetic relationship is hypothesized by:
- Morphological characters
E.g.size, shape, structure- Cheaper and more accessible
- Molecular characters
E.g.DNA and protein sequences- Dominant and more accurate
Types of evolutionary similarity
- Homology: similarity between taxa due to shared history
- Arises through divergent evolution
E.g.the arrangement of bones in the forelimbs of mammals
- Analogy: similarity between taxa due to adaptation to similar environments
- Arises through convergent evolution
E.g.modification of forelimbs into fins in both whales and penguins- Homoplasy: molecular analogy
In general, the more complex the features similar between two taxa (e.g. similar DNA sequences), the more likely they are homologous.
[!example] Analogy: marsupial and placental evolve similar structures in dark tunnels.
[!example] Analogy: sugar glider and flying squirrel evolve gliding wings independently.
[!example] Homology: chicken and human embryos look similar.
Ajitani Hifumi