1 / 10

Parental Care and Investment

Parental Care and Investment. Psychology 3107. Introduction. In many species, eggs are lad after reproduction and the young are left to fend for themselves Parents can go make more… However, parents do care for young in varying degrees and ways in a number of species. A Definition.

magee-workman
Download Presentation

Parental Care and Investment

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Parental Care and Investment Psychology 3107

  2. Introduction • In many species, eggs are lad after reproduction and the young are left to fend for themselves • Parents can go make more… • However, parents do care for young in varying degrees and ways in a number of species

  3. A Definition • Parental Investment: • Anything done for the offspring that increases offspring survival, while decreasing the parents’ ability to produce additional offspring • So there is a cost!

  4. Sex Differences • So, why is it then that, as a rule, females give more investment than males? • Reliability of paternity • Pretty obvious • Gamete release • ‘my work here is done’ • Association with young • The females are there at birth

  5. Parent Offspring Conflict • If there is investment, the offspring would like it to go on forever, the parents, eventually want to have more babies • OK, look at this genetically, the mother and daughter/son share .5 of their genes • At some point, the mother would be better served by having another child.

  6. Parent offspring conflict • The conflict continues until the parental cost = 2 x the benefits to the offspring • Then, it is in the best interests of the parent and the kid to have another kid show up • Not just the continuation of investment, but also the amount can be a bone of contention

  7. Sex Allocation • ‘Shall we have girls or boys dear?’ • Not as odd a question as it seems • Think evolutionarily • Proximate mechanisms? • Stress • X v y sperm • Temperature

  8. Parent Offspring Conflict • The second kid would be related to the mom by .5, to the other kid by .5 • This is NOT in the best interests of kid no.1 • It shares 1.0 of its genes with itself, only .5 with new kid • The offspring are only ½ as interested in parental costs as the parent is

  9. More sex allocation • Low Ranking pairs may have more females, high ranking pairs have more males • Example • Zebra finches • More attractive males have more males • (Burley, 1981)

  10. Conclusions • Trivers (1974) parent offspring conflict model is an amazing thing • You must think evolutionarily • This stuff dovetails nicely with the stuff on mating systems

More Related