Question

T/F Selection only affects fitness in terms of fecundity

Answer 1

The statement is false because fitness is affected by survival, mating success, and the production of offspring, with parental care and mating behaviors playing significant roles. Sperm-depleted male fruit flies choosing more fecund females exemplify the multifactorial nature of fitness.

Step-by-step explanation:

The statement that selection only affects fitness in terms of fecundity is false. Fitness is influenced by several factors, including an organism's survival, mating success, and ability to produce offspring, not just fecundity alone. A key example of this multifaceted approach to selection can be seen in the mating behaviors of sperm-depleted male fruit flies. These flies choose larger, more fecund females as it maximizes their limited reproductive resources and increases their chances of passing on their genes.

Parental care also plays a vital role in an organism's fitness. In animal species with high fecundity, typically less energy is invested in parental care. This strategy allows a greater number of offspring, albeit with a higher susceptibility to predation. Conversely, species that invest more in parental care tend to have fewer offspring, but those offspring have a higher survival rate. This energy tradeoff and varying parental care strategies demonstrate the complexity of evolutionary fitness beyond just fecundity. Moreover, the behavior of organisms, like mating choices affected by the physiological state of sperm-depleted males, is essential in evolutionary biology, particularly within the discipline of behavioral biology or ethology.

Answer 2

The statement is false; selection affects fitness through numerous factors such as survival, mating success, and fecundity. Parental care and reproductive strategies, as well as sexual selection, greatly influence an individual's fitness beyond just fecundity.

Step-by-step explanation:

The statement "Selection only affects fitness in terms of fecundity" is false. Selection affects fitness through many factors, such as survival and mating success, in addition to fecundity. Fecundity denotes the potential reproductive capacity of an organism and is tied to the number of offspring produced. However, in the context of natural selection, individual fitness is not determined solely by fecundity.

Parental care is another aspect affecting fitness. It is generally inversely related to fecundity; species that produce many offspring tend to provide less care to each one. This lack of care makes the offspring more vulnerable, but the sheer number of offspring increases the odds of species survival. Reproductive strategies are influenced by an organism's energy budgets, as seen in studies of sperm-depleted male fruit flies selecting more fecund females — this maximizes their reproductive opportunities under limited conditions.

Additionally, sexual selection can also play a significant role in fitness. Certain traits can make an individual more attractive to potential mates, impacting reproductive success. For example, in many species, males have developed traits that help them compete for or attract mates, such as larger body size or elaborate ornaments. Thus, fitness is a composite measure influenced by various factors, including but not limited to fecundity.