Evolution 2 Flashcards
Altruism
To act kindly to others
Kin selection
Parents consume energy and resources to raise their kids but still pass on their genetic legacy
Siblings and cousins
Siblings share half of their genes and first cousins share 1/8
Eusocial insects
live only in social groups
Coefficient of relatedness
diagram that explains how related different individuals are
Females and males
Females are diploid and males are haploid
Risk of eusocial insects
cheating
Only non-arthropod animal to form social group
Naked-mole rats
reciprocal altruism
another source of altruistic behavior, 1. Frequent interactions. 2. Recognizing individuals. 3. Remembering past interactions. 4. Assisting only those who provided assistance in the past
Coevolution
when the evolution of one species affects evolution of another species
Mycorrhizae
Beneficial relationship between fungus and root plants
Ant-acacias
have hollow thorns that ants live in and will defend the tree
Pollination
wind pollination, animal pollination
Pseudo-copulation
The flower mimics a female looking up and releases a pheromone
Other form of dispersal for plants
Fruit dispersal
Elaiosomes
fleshy attachments to attract small animals… cheaper than making full fruits
Speciation
when two diverging groups are unable to produce viable offspring together
anagenesis
one species becomes another
cladogenesis
a small population branches off and now there are two species
biological species concept
the new group can’t interbreed with the original population
morphological species concept
the species really look different
Allopatric speciation
when groups are physically isolated
Parapatric speciation
when groups are somewhat isolated
sympatric speciation
when groups are not physically isolated
hybrid zones
area where populations that split only recently came back into contact
Genetic bottleneck
event that results in a change of the dwindling population, ex. northern elephant seals
Founder effect
individuals who are founders have a major effect on the genetic composition of the population
Ring species
interbreeding populations where members in the far ends cannot interbreed, even if they meet each other. ex. salamanders
Sticklebacks
both sympatric and allopatric speciation
Polyploidy
Having multiple copies of chromosomes
“Pre-zygotic” isolation mechanism
these operate before mating occurs. they tend to prevent intermingling of species. Ex. different breeding seasons and lack of fit in genitalia
Adaptive radiation
the daughter species that “radiate” from the mother species
convergent evolution
If selective pressures are similar unrelated species may develop similar adaptations
Feeding specialization
Cichlids developing different eating methods to reduce competition in their environment
Phenotypic plasticity
The ability of individual genotypes to develop of different phenotypes due to unique environmental conditions
Mouth-brooding
A behavioral adaptation that helps parents prevent predation of their young/eggs
Sexual dimorphism
physical differences between sexes is related to finding a mate
Phylogeny
akin to a family tree
