The evolutionary constraints that lead to the evolution of sexual reproduction are framed by the better repair mechanisms that repair fatal mutations, as well as the need for variable immune systems imposed on large organisms by parasites, such as viruses and bacteria. Besides the evolution of sexual reproduction, these factors also affect mate choice, especially as regards the gene complex that encodes the immune system. The need to increase both the likelihood of gametes to encounter each other as well as sufficient provision of nutrition for the offspring then leads to the evolution of two sexes: large numbers of small mobile sperms ensure that gametes meet, whereas large egg cells full of energy provide for the zygote, thus leading to a developmental advantage. The asymmetric investment in the offspring then affects not only mate choice criteria, but also cognitive strategies. Men place more importance on youthfulness and fertility than women, who regard resource holding potential as a more relevant criterion. Consequently, female jealousy is connected to endangered access to resources, whereas male jealousy is rooted in paternal uncertainty. Cognitive adaptations developed to ensure reproductive success show sex differences, such as in error management. The most obvious function of sexual behavior is reproduction. To foster the benefits for the offspring, reproduction partners should also develop an emotional bond, which is mediated by hormones connected to sexual intercourse. With increasing age, reproduction loses importance, while pair bonding functions remain relevant. Therefore, sexuality never ceases to be part of a relationship.

Keywords:
Mate choice, Sex difference, Reproduction, Error management, Evolution, Sexuality
This content is only available via PDF.
© 2009 S. Karger AG, Basel
2009
Copyright / Drug Dosage / Disclaimer
Copyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher.
Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in government regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug.
Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.