06b male repro organs

06b male repro organs - Penile Morphology &...

Info iconThis preview shows pages 1–5. Sign up to view the full content.

View Full Document Right Arrow Icon
E.g. Os Penis & Spines
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
E.g. Curvature & Papillae
Background image of page 2
Evolution of Male Genitalia  – specialized structures as a species isolating mechanism. Genitalic recognition hypothesis  - fertilization occurs only if appropriate copulatory  stimulation. F ‘recognizes’ M. Pleiotropism  - side effect, accident of evolution as result of changes in other systems. Mechanical conflict of interest  - to bypass F barriers. Sexual selection  - F choice (‘internal courtship device’).  M-M competition: penile morphology (especially penile spines) may contribute to  improved sperm competition.
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Sexual Selection of Penile Morphology Answer:   “depends” Question: “is bigger better?” F’s view of M:  degree of sexual dimorphism in body size            size of erect penis
Background image of page 4
Background image of page 5
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Penile Morphology & Mating Systems Monogamy & Polygamy: Multi-M Multi-F & Dispersed: * small, short penis * elongated penis (if F has sex skin, adds depth => penis even longer) * relatively unspecialized (e.g. fewer spines, less color) * exceedingly diverse in specializations * copulate less often => maintain erection less frequently => smaller bulbocavernosus muscle * copulate often => maintain erection frequently => larger BC muscle * or intromission maintained post ejaculation (prolonged) => os penis * ejaculate less often => semen produced in smaller volume => smaller, less elaborate seminal vesicles * ejaculate often => semen produced in larger volume => larger, more lobulated seminal vesicles...
View Full Document

Page1 / 5

06b male repro organs - Penile Morphology &...

This preview shows document pages 1 - 5. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online