Lecture 15 - Dementia, Natural Selection And Senescence Flashcards
What determines the length of life of an individual?
An individual must survive to sexual maturity and have long enough to reproduce and look after their offspring, so you have to survive through all of that…but not really any longer because then resources get taken away from reproduction and put toward longevity
What is sexual selection?
Natural selection that selects adaptations which increase the number or choice of mates e.g. Peacocks tails or fights between stags
How does female mate choice help keep life length stable?
It acts as a gene filter, because females want males with good genes, and not short lived/ unhealthy lives. So it filters out males with short lifespans.
In what way may sexual selection like mate choice or male competition reduce life length?
Testosterone is damaging to health but it is necessary to win male vs male competition. Therefore males have adapted to be able to reproduce quickly and frequently, and females have slightly longer lifespans because they can’t.
Examples of how males live shorter lives?
Peacocks tails lead to increase predation risk,
Elephant seals fight to the death to be alpha
Blackbirds sing on exposed perches
Define dementia
Global decline in 3 or more faculties of cognition for example, memory, intelligence, personality, language , executive functioning and emotionality.
What kind of changes do you see in demented patients?
Reduced ability to work or self care, change in personality, hoarding, hiding or wondering behaviour , change in sleep patterns with more activity at night
What is the epidemiology of dementia?
Will everyone have it?
65 - 5%
80 - 20%
90 - 50%
If everyone lived long enough they probably would all suffer dementia
Define: senescence
Age related decline in function and then death
