evolution and domestication of dogs Flashcards
dogs closest relative
grey wolf (canis lupus)
dog and grey wolf are sister taxa ie
both evolved from common ancestor
order and family
carnivora, canidae
miacis
ancestor of canidae, 60 MYA, small weasel-like mammal
miacis evolved into
cynodictis (greek for inbetween dog)
elongated limbs and feet for running
carnassial teeth specialized for shearing
expanded cranium and brain
evolution of dogs is characterized by what 3 traits
elongated limbs and feet for running
carnassial teeth specialized for shearing
expanded cranium and brain
cynodictis gave rise to 2 branches
africa and eurasia
eurasian branch: tomarctus is progenitor for wolves dogs and foxesw
cynodictis have rise to african and eurasian branch
which was progentior for wolves, dogs and foxes
eurasian: tomarctus
domestication
process of developing mutually useful relationship between animals an humans
domestication criteria (6)
- flexible diet
- reasonable growth rate
- breed in captivity
- pleasant disposition
- steady temperament
- modifiable social hierarchy
did dogs evolve from the eurasian grey wold (canis lupus)
NO, originally thought yes but they both evolved from a now extinct common wolf ancestor
they r close relatives but dogs did not evolve from them
dogs were domesticated
twice
initial wold population split into
european and asian populations
out of the european and asian wold populations, which were most modern dogs derived from
asian
dogs were domesticated before of after humans transitioned to agriculture societies
BEFORE
why might have dogs been domesticated
- ate carcasses humans left so over time moved close to humans
- people who had dogs during hunt would have advantage
- migrating wolves (the ones following humans) give up their territory and less likely to provide with resident territorial wolves
some shared features of humans and dogs/ wolf packs
- hierarchical order
- work cooperatively
- strong kinship
- suspicious of outsiders
- care for and protect young even if not theirs
- refined ability to interpret moods
ability of dogs to read human gestures (2 examples)
left gaze bias: when humans meet new face eyes shift to left to settle on right side of face because right side better at expressing emotional state dogs do this to only when looking at humans
finger pointing
dogs have ability to digest
starch; dogs have multiple (4-30) copies of a gene for amylase where as wolves only have 2
extended eye contact between dogs and their humans increases
oxytocin in both
paedomorphosis
retention of juvenile traits into adulthood
pleiotropy
one gene affects several traits
some phenotypes associated with domestication are similar to those seen in individuals with pathologies in
neural crest development
role of sorcs1 gene
mutations in humans associated w behavioural disorders
when animals are domesticated the selection processes that influence wild animals are removed or disrupted, such as:
- reduced fighting between males
- fewer males for females to choose between
- more reliable sources of food
- fewer predators
does size differentiation in early dogs have anything to do with current dog breeds? why?
no
because the oldest modern dog breeds are only 500 yr olds and most are only 150 yrs old