How can evolutionary fitness be measured? Select True or False for each statement. T/F Document how long individuals survive. T/F Count the number of healthy, fertile offspring produced. T/F Determine which individuals are strongest. T/F Determine which phenotype is the most common.

Video transcript

Welcome back. Here's our next problem. How can we determine if one variant of a species is more fit than another? What we recall that fitness in this sense is the ability, more likelihood of an organism two survive and reproduce. So let's look at our answer choices to see which would help us determine if one very variant is more fit than another choice. A says they can reproduce successfully. Well this would be how we would determine this because fitness has to do with how likely is an organism is to survive and then to reproduce. So successful reproduction would determine that. But let's be thorough and look at the others choice. B says they have a bigger appetite. Well again, fitness doesn't have to do with the actual condition of the body. It's just how likely that individual is to survive to reproduce to Joyce being out? Our correct answer choice C. Says they have a larger body mass. Again, body mass doesn't have to do with fitness necessarily. Um We're just looking at how much more likely something is to reproduce. So body mass is not a determiner of that. That's not our answer. And finally, Choice D. They can attract many mates that could directly be part of it. But it doesn't necessarily mean they will successfully reproduce which is the actual measure of fitness. How likely are they to reproduce successfully and pass on their genes? So choice D. Is not the correct answer. Again, how can we determine if one variant of a species is more fit than another? Choice A. They can reproduce successfully. See you in the next video.