Concept explainers
To determine:
Why the evolution selects for males that mimic females, even though the chances of success is relatively low.
Concept introduction:
Australian giant cuttlefish (Sepia apama) show sexual dimorphism. The males and females of the species greatly differ from each other in appearance. Females have shorter arms and dark patches on a white background. On the other hand, the males have longer arms and are whiter.
The species has a sex ration of four males to one female, leading to fierce competition among males for fathering the offspring. The largest males mate with the females and guard them after insemination. The males fight with other males that try to inseminate the females. This behavior accounts for larger male’s reproductive success.
The smaller males use another behavioral strategy called deception. They disguise themselves as a female by hiding the arms and changing skin color. This behavior allows the smaller males to increase their chances of reproductive success.
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Biology: Concepts and Investigations
- What is meant by “sexual selection”? a. Having an XX or XY chromosome pattern determines whether one develops as a female or a male. b. Hormones during a sensitive period produce longlasting effects on anatomy and behavior. c. Some people choose to switch from one gender identity to another. d. Evolution favors characteristics that make an individual more appealing to the opposite sex.arrow_forwardHow and why do female mating preferences evolve?arrow_forwardDo females select mates basedon traits indicative of “good genes”?arrow_forward
- Which of these situations offers the lowest “opportunity for selection” for males? A. Females choose mates with a fancy ornament. B. Every female chooses one male to mate with for life. C. Locations that females need access to in order to reproduce are rare. D. Males fight each other for access to groups of females.arrow_forwardHow do female preferences for certain male characteristics evolve in the first place?arrow_forwardOn what assumptions Ratio of Males to Females in Humans is determined ?arrow_forward
- What are Mate Preferences Between Women and Men?arrow_forwardWhat sorts of studies would we undertake in order to confirm that human mating behaviors are truly driven by biological forces, e.g., evolutionary fitness, rather than cultural or societal advantages?arrow_forwardWith your knowledge of sexual selection theory, can you formulate a hypothesis that explains why female courtship might have evolved in this species? Is there anything about pipefish biology that might support your hypothesis?arrow_forward
- Do you believe that humans (whether consciously or unconsciously) use natural selection when choosing a mate? Why or why not?arrow_forwardIn seahorses, males incubate and care for offspring. Thus, the males are more likely to be tied up in reproduction at any point in time relative to females. Which sex do you predict will be the choosey sex in this species and why? Males -- because fewer are available to mate Males – because male-male competition is incredibly strong Females – because sperm are cheap to produce Female – because the operational sex ratio is biased in their favorarrow_forward why do females have a greater disadvantage compared to males concerning sexual reproduction? How has this difference between the sex shape sexual selection in general? Choose one form of communication and explain how it is used by competing sex is attracting a mate. arrow_forward
- Biology (MindTap Course List)BiologyISBN:9781337392938Author:Eldra Solomon, Charles Martin, Diana W. Martin, Linda R. BergPublisher:Cengage Learning