BIOL3045 Lecture Notes - Lecture 13: Semen, Anisogamy, Coevolution
3 Jul 2018
School
Department
Course
Professor
Animal Ecological Physiology BIOL3045 460381099
Lecture 13: Paternal effects.
Parental Investment: any investment by the parent in an individual offspring that increases the
offspring’s chance of surviving (and hence reproductive success) at the cost of the parent’s ability to
invest in other offspring.
Anisogamy: Many sperm compete to fertilize the egg.
Why paternal investment? Traits that protect paternity can co-evolve with care. Can increase
mating success. Example: subordinate males - biased sex ratio. Paternal offspring care can affect a
broad range of offspring traits. Because paternal influences on offspring can be mediated by
maternal responses, it is difficult to determine whether they should be defined as a maternal or
paternal effect. Non-genetic effects, Initially overlooked as males typically invest less in offspring
than females, now recognised as common and widespread. Difficult to disentangle from maternal
effects. Effects in offspring often sex-specific. Can be mediated by sperm or seminal fluid.
Document Summary
Parental investment: any investment by the parent in an individual offspring that increases the offspring"s (cid:272)han(cid:272)e of surviving (cid:894)and hen(cid:272)e reprodu(cid:272)tive su(cid:272)(cid:272)ess(cid:895) at the (cid:272)ost of the parent"s a(cid:271)ility to invest in other offspring. Anisogamy: many sperm compete to fertilize the egg. Traits that protect paternity can co-evolve with care. Paternal offspring care can affect a broad range of offspring traits. Because paternal influences on offspring can be mediated by maternal responses, it is difficult to determine whether they should be defined as a maternal or paternal effect. Non-genetic effects, initially overlooked as males typically invest less in offspring than females, now recognised as common and widespread.
