1. Mechanisms for kin recognition: Preferences that develop as a result of association during ontogeny -“Mediated recognition” through a 3 rd individual Phenotypic matching Depends on a strong correlation between phenotypic similarity and genotypic similarity

2. Environmental and social factors determine the timing, form,and limits of kin recognition Learned mechanisms: Location (in nest, territory) Olfactory, auditory, visual cues Prolonged social contact Genetic mechanisms: phenotypic matching

3. Wood frog tadpoles

4. American toad tadpoles

5. Belding’s ground squirrels SiblingsNon-kin

6. Belding’s ground squirrels Litter-mates

7. Familiar odor Unfamiliar odor Duration (sec) Frequency

8. Littermate odor Non-littermate odor Duration (sec) Frequency

9. Help to offspring minus help to all unrelated juvs, Help to offspring minus help to ‘behavioral’ offspring Help to ‘behavioral’ offspring minus help to unconnected juvs, Difference between % of help given to juveniles of each type 15 8 9 Aid given by adult male baboons to juveniles

10. Factors favoring phenotypic matching: Polygamy: distinguish full from half sibs If nests contain both related and unrelated young Brood parasitism BUT it seems that phenotypic matching doesn’t occur as often as it should

11. Research on congenic mice suggests that: Individuals with the same MHC (major histocompatability complex) treat each other as kin. The neuropeptide oxytocin seems to be necessary for social recognition.

12. Function of kin recognition: Cooperation (kin selection) Inbreeding avoidance

13. Types of “kin” recognition: 1. Kin vs. non-kin 2. Within kin class, different degrees of r *3. Other individuals’ kin (or close associates) *4. Abstract kin classes (e.g. ‘uncle’, ‘sister’) * = not favored by kin selection

14. Protocol for playback experiments: Two unrelated females (A and B) are sitting together. A is dominant to B. On 3 different occasions, play: 1. Kin of both involved: Threat-grunt of A’s relative paired with scream of B’s relative 2. Kin of one involved: Threat-grunt of A’s relative paired with scream of D 3. Kin of neither involved: Threat-grunt of C paired with scream of E.

15. Subjects look toward each other Duration of looking (sec) Both kin Dom.kin No kin Dominant female (A) Subordinate female (B)

16. A supplants BA appr. BB appr. A Subjects’ behavioral responses Duration of looking (sec) Both kin Dom.kin No kin Behavior following experiment