Question

In a few species, males are limiting and females must compete with rival females over access to them despite female eggs being larger than male sperm. How can this occur?

1) Males in these species invest in offspring in other ways that offset the initial female investment into gametes.
2) The operational sex ratio is skewed toward females in these role-reversed species, because females recycle between breeding events faster than males do.
3) Elaborate courtship and repeated matings in these species result in unusually high certainty of paternity for the caring males.
4) All of the above.
5) None of the above.

Answer 1

In certain species with sex-role reversal, females compete for males due to males investing in offspring beyond gamete production, a skewed operational sex ratio favoring females, and males ensuring high paternity certainty through elaborate courtship, making the correct answer 'All of the above'.

Step-by-step explanation:

The question explores a scenario where in a few species with sex-role reversal, females compete for males, an uncommon situation considering females typically invest more in gamete production. There are several explanations for why this might occur. Firstly, males could be investing in offspring in ways other than gamete production, balancing the initial female investment into large gametes. Secondly, the operational sex ratio could be skewed towards females, leading them to compete more for the available males. Finally, the certainty of paternity might be higher due to elaborate courtship and repeated matings by males, thus making them choosier about their partners.

In conclusion, these factors synergistically explain why females in these species can find themselves in the position of competing for males. Therefore, the correct answer to this question is option 4) All of the above. This comprehensive approach acknowledges the complex nature of sexual selection and the varying reproductive strategies across different species.