Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
49 Cards in this Set
- Front
- Back
|
Traits of an animal
|
Multicellular eukaryotes
Heterotrophic No cell walls Collagen for support HOX genes Tissues and nervous system |
|
|
Adaptive evolution
|
Makes individual more suited to their environment
|
|
|
Indirect reproduction
|
Genes help relative reproduce
Kin selection |
|
|
Fitness
|
Measure of an individual/genes genetic contribution to the next generation relative to others in the population
Only character that natural selection works on directly |
|
|
Measure fitness via
|
Tracking gene frequencies over time
|
|
|
Irreducible complexity
|
Complex eye needs all parts to function
One mutation unlikely to create whole eye No benefit unless whole? Many eye types via natural selection |
|
|
Mutation rate in humans
|
~ 60/person/generation
|
|
|
Disruptive selection
|
Diverse types in the same population
|
|
|
Negative frequency dependence
|
Fitness drops as frequency increases
|
|
|
Heterozygote advantage
|
Maintains both alleles
|
|
|
Biological species concept
|
Populations reproductively isolated from other populations in the area
Can diverge Only works for sexual Hard to determine |
|
|
Phylogenetic species concept
|
Irreducible cluster of organisms diagnosible different from other clusters
Parental pattern of descent Ignores how species comes about Easy and quick to determine |
|
|
Evo-devo view
|
Most important changes are due to regulatory gene mutations
No strong evidence |
|
|
Traditional view of genetics of species differences
|
No special role for regulatory genes in species divergence
|
|
|
Chimps and humans
|
99% identical genes
80% proteins differ by 1+ aa |
|
|
dn = ds
|
Evolving neutrally
|
|
|
dn < ds
|
Non-synonymous under negative selection
|
|
|
dn > ds
|
Non-synonymous under positive selection
|
|
|
Trees used for:
|
Evolutionary relationships
Morphological evolution Speciation Co-evolution Rate |
|
|
Outgroup
|
1+ taxa known to have diverged before group being studied
|
|
|
Monophyly
|
All share single common ancestor
Birds and mammals |
|
|
Paraphyly
|
Doesn't include all branches from common ancestor
Lizards |
|
|
Polyphyly
|
Grouping organisms with others inbetween
Missing out some branches |
|
|
Parsimony reconstruction
|
Between organisms not connected directly
Fewest state changes Least evolution Multiple train gain or gain then losss |
|
|
Subphylum Trilobitomorpha
|
Extinct
Gills on limbs No jaws Marine |
|
|
Subphylum Cherlicerata
|
Chelicerae
Book gills/lungs Spiders Scorpions |
|
|
Subphylum Myriapoda
|
Mandibles
Tracheae Centipedes |
|
|
Subphylum Crustacea
|
Mandibles
Gills on limbs Crabs |
|
|
Subphylum Hexapoda
|
Insects
Young group Terrestrial Mandibles Tracheae |
|
|
Homoplasy
|
Convergent evolution of shared characters
|
|
|
Arthropod characters
|
Bilateral, segmented, teloblastic growth
Triploblast, tagmosis Protostomious, appendages on each segment Haemocoel, cilia absent Open circulation, ecdysis moulting |
|
|
Grade
|
Grouping based on morphological similarity
|
|
|
Uniramous limbs
|
1 set segments
|
|
|
Biramous limbs
|
2 sets segments
|
|
|
Polyphyletic origin suggestion
|
3 origins - 2 limb types, no mandible type
|
|
|
Lobopod
|
Likely arthropod ancestor
Similar to onychophora (velvet worms) and tardigrada (water bears) |
|
|
Burgess Shale
|
Fossils preserved due to sea cliff collapse
15 possible rooted trees 505 mya Some easily slotted into current places |
|
|
Monophyla origin
|
More likely
Molecular data, HOX genes used Mitochondrial genome, limb development, tracheal system |
|
|
Articulata hypothesis
|
Arthropoda + annelida
Shared characters: segments with 1 appendage each, CNS with ventral cords, segmented ganglia, dorsal tubular heart, teloblastic |
|
|
Coelomata / Pseudocoelomate hypothesis
|
Arthropoda + annelida + mollusca
|
|
|
Protostomia
|
Articulata + mollusca + others
Lophotrochozoa + ecdysozoa |
|
|
Coelomata
|
Protostomia + deuterostomia
|
|
|
Differences between annelids and arthropods
|
Annelids don't moult, coelomic
Arthropods haemocoel Larval stages |
|
|
Ecdysozoa
|
Nematoda + panarthropoda
Moutling, lack of cilia, triradiate pharynx |
|
|
Lophotrochozoa
|
Annelida + mollusca
|
|
|
Phylogenetic fuses
|
How a group diverged
Short Long and gradual Long and rapid |
|
|
Uniramia
|
Hexapoda + myriapoda
Tracheal gas exchange, uniramous appendages, Malphigian tubules, loss of second antennae, loss of mandibular palps Convergence?? |
|
|
Mandibulate theory
|
Crustacea + uniramia
|
|
|
TCC Hypothesis
|
Crustacea close to chelicerata
|
